Commit graph

6068 commits

Author SHA1 Message Date
Ed Swierk
3a9f84d354 signals, debug: fix BUG: using smp_processor_id() in preemptible code in print_fatal_signal()
With print-fatal-signals=1 on a kernel with CONFIG_PREEMPT=y, sending an
unexpected signal to a process causes a BUG: using smp_processor_id() in
preemptible code.

get_signal_to_deliver() releases the siglock before calling
print_fatal_signal(), which calls show_regs(), which calls
smp_processor_id(), which is not supposed to be called from a
preemptible thread.

Make sure show_regs() runs with preemption disabled.

Signed-off-by: Ed Swierk <eswierk@aristanetworks.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-27 00:36:19 +01:00
Linus Torvalds
2034563ca3 Merge git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild-fixes
* git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild-fixes:
  kbuild: fix kbuild.txt typos
  kbuild: print usage with no arguments in scripts/config
  Revert "kbuild: strip generated symbols from *.ko"
2009-01-26 15:10:37 -08:00
Linus Torvalds
37f5fed555 Merge branch 'sh/for-2.6.29' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6
* 'sh/for-2.6.29' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6: (22 commits)
  dma-coherent: Restore dma_alloc_from_coherent() large alloc fall back policy.
  dma-coherent: per-device coherent area is in pages, not bytes.
  sh: fix unaligned and nonexistent address handling
  nommu: Stub in vm_map_ram()/vm_unmap_ram()/vm_unmap_aliases().
  sh: fix sh-sci / early printk build on sh7723
  sh: export the sh7343 JPU to user space
  sh: update defconfigs.
  serial: sh-sci: Fix up SH7720/SH7721 SCI build.
  sh: Kill off obsolete busses from arch/sh/Kconfig.
  sh: sh7785lcr/highlander/hp6xx need linux/irq.h.
  sh: Migo-R MMC support using spi_gpio and mmc_spi.
  sh: ap325rxa MMC support using spi_gpio and mmc_spi
  sh: mach-x3proto: needs linux/irq.h.
  sh: Drop the BKL from sys_execve() on SH-5.
  sh: convert rsk7203 to use smsc911x.
  sh: convert magicpanelr2 platform to use smsc911x.
  sh: convert ap325rxa platform to use smsc911x.
  sh: mach-migor: Add tw9910 support.
  sh: mach-migor: Delete soc_camera_platform setup.
  sh: mach-migor: Add ov772x support.
  ...
2009-01-26 10:12:08 -08:00
Linus Torvalds
3386c05bdb Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  debugobjects: add and use INIT_WORK_ON_STACK
  rcu: remove duplicate CONFIG_RCU_CPU_STALL_DETECTOR
  relay: fix lock imbalance in relay_late_setup_files
  oprofile: fix uninitialized use of struct op_entry
  rcu: move Kconfig menu
  softlock: fix false panic which can occur if softlockup_thresh is reduced
  rcu: add __cpuinit to rcu_init_percpu_data()
2009-01-26 09:47:56 -08:00
Linus Torvalds
1e70c7f7a9 Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  hrtimers: fix inconsistent lock state on resume in hres_timers_resume
  time-sched.c: tick_nohz_update_jiffies should be static
  locking, hpet: annotate false positive warning
  kernel/fork.c: unused variable 'ret'
  itimers: remove the per-cpu-ish-ness
2009-01-26 09:47:43 -08:00
Linus Torvalds
810ee58de2 Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (29 commits)
  xen: unitialised return value in xenbus_write_transaction
  x86: fix section mismatch warning
  x86: unmask CPUID levels on Intel CPUs, fix
  x86: work around PAGE_KERNEL_WC not getting WC in iomap_atomic_prot_pfn.
  x86: use standard PIT frequency
  xen: handle highmem pages correctly when shrinking a domain
  x86, mm: fix pte_free()
  xen: actually release memory when shrinking domain
  x86: unmask CPUID levels on Intel CPUs
  x86: add MSR_IA32_MISC_ENABLE bits to <asm/msr-index.h>
  x86: fix PTE corruption issue while mapping RAM using /dev/mem
  x86: mtrr fix debug boot parameter
  x86: fix page attribute corruption with cpa()
  Revert "x86: signal: change type of paramter for sys_rt_sigreturn()"
  x86: use early clobbers in usercopy*.c
  x86: remove kernel_physical_mapping_init() from init section
  fix: crash: IP: __bitmap_intersects+0x48/0x73
  cpufreq: use work_on_cpu in acpi-cpufreq.c for drv_read and drv_write
  work_on_cpu: Use our own workqueue.
  work_on_cpu: don't try to get_online_cpus() in work_on_cpu.
  ...
2009-01-26 09:47:28 -08:00
Ingo Molnar
bfe2a3c3b5 Merge branch 'core/percpu' into perfcounters/core
Conflicts:
	arch/x86/include/asm/hardirq_32.h
	arch/x86/include/asm/hardirq_64.h

Semantic merge:
	arch/x86/include/asm/hardirq.h
	[ added apic_perf_irqs field. ]

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-23 10:20:15 +01:00
Steven Rostedt
91a8d07d82 ring-buffer: reset timestamps when ring buffer is reset
Impact: fix bad times of recent resets

The ring buffer needs to reset its timestamps when reseting of the
buffer, otherwise the timestamps are stale and might be used to
calculate times in the buffer causing funny timestamps to appear.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-22 10:31:58 +01:00
Thomas Gleixner
6552ebae25 Merge branch 'core/debugobjects' into core/urgent 2009-01-22 10:03:02 +01:00
Ingo Molnar
77835492ed Merge commit 'v2.6.29-rc2' into perfcounters/core
Conflicts:
	include/linux/syscalls.h
2009-01-21 16:37:27 +01:00
Steven Rostedt
1092307d58 trace: set max latency variable to zero on default
Impact: trace max latencies on start of latency tracing

This patch sets the max latency to zero whenever one of the
irq variant tracers or the wakeup tracer is set to current tracer.

Most developers expect to see output when starting up a latency
tracer. But since the max_latency is already set to max, and
it takes a latency greater than max_latency to be recorded, there
is no trace. This is not the expected behavior and has even confused
myself.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-21 15:21:30 +01:00
Steven Rostedt
a442e5e0a2 trace: stop all recording to ring buffer on ftrace_dump
Impact: limit ftrace dump output

Currently ftrace_dump only calls ftrace_kill that is a fast way
to prevent the function tracer functions from being called (just sets
a flag and clears the function to call, nothing else). It is better
to also turn off any recording to the ring buffers as well.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-21 15:21:30 +01:00
Steven Rostedt
faf6861ebd trace: print ftrace_dump at KERN_EMERG log level
Impact: fix to print out ftrace_dump when expected

I was debugging a hard race condition to only find out that
after I hit the race, my log level was not at level to show
KERN_INFO. The time it took to trigger the race was wasted because
I did not capture the trace.

Since ftrace_dump is only called from kernel oops (and only when
it is set in the kernel command line to do so), or when a
developer adds it to their own local tree, the log level of
the print should be at KERN_EMERG to make sure the print appears.

ftrace_dump is not called by a normal user setup, and will not
add extra unwanted print out to the console. There is no reason
it should be at KERN_INFO.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-21 15:21:30 +01:00
Lai Jiangshan
551b4048b3 ring_buffer: reset write when reserve buffer fail
Impact: reset struct buffer_page.write when interrupt storm

if struct buffer_page.write is not reset, any succedent committing
will corrupted ring_buffer:

static inline void
rb_set_commit_to_write(struct ring_buffer_per_cpu *cpu_buffer)
{
	......
		cpu_buffer->commit_page->commit =
			cpu_buffer->commit_page->write;
	......
}

when "if (RB_WARN_ON(cpu_buffer, next_page == reader_page))", ring_buffer
is disabled, but some reserved buffers may haven't been committed.
we need reset struct buffer_page.write.

when "if (unlikely(next_page == cpu_buffer->commit_page))", ring_buffer
is still available, we should not corrupt it.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-21 15:21:30 +01:00
Frederic Weisbecker
00f57f545a tracing/function-graph-tracer: fix a regression while suspend to disk
Impact: fix a crash while kernel image restore

When the function graph tracer is running and while suspend to disk, some racy
and dangerous things happen against this tracer.

The current task will save its registers including the stack pointer which
contains the return address hooked by the tracer. But the current task will
continue to enter other functions after that to save the memory, and then
it will store other return addresses, and finally loose the old depth which
matches the return address saved in the old stack (during the registers saving).

So on image restore, the code will return to wrong addresses.
And there are other things: on restore, the task will have it's "current"
pointer overwritten during registers restoring....switching from one task to
another... That would be insane to try to trace function graphs at these
stages.

This patch makes the function graph tracer listening on power events, making
it's tracing disabled for the current task (the one that performs the
hibernation work) while suspend/resume to disk, making the tracing safe
during hibernation.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-21 15:21:30 +01:00
Paul Mundt
0609697eab dma-coherent: Restore dma_alloc_from_coherent() large alloc fall back policy.
When doing large allocations (larger than the per-device coherent area)
the generic memory allocators are silently fallen back on regardless of
consideration for the per-device constraints.

In the DMA_MEMORY_EXCLUSIVE case falling back on generic memory is not
an option, as it tends not to be addressable by the DMA hardware in
question. This issue showed up with the 8139too breakage on the
Dreamcast, where non-addressable buffers were silently allocated due to
the size mismatch calculation -- while it should have simply errored out
upon being unable to satisfy the allocation with the given device
constraints.

This restores fall back behaviour to what it was before the oversized
request change caused multiple regressions.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-01-21 18:51:53 +09:00
Adrian McMenamin
cdf57cab27 dma-coherent: per-device coherent area is in pages, not bytes.
Commit 58c6d3dfe4 ("dma-coherent: catch
oversized requests to dma_alloc_from_coherent()") attempted to add a
sanity check to bail out on allocations larger than the coherent area.

Unfortunately when this was implemented, the fact the coherent area
is tracked in pages rather than bytes was overlooked, which subsequently
broke every single dma_alloc_from_coherent() user, forcing the allocation
silently through generic memory instead.

Signed-off-by: Adrian McMenamin <adrian@mcmen.demon.co.uk >
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-01-21 18:47:38 +09:00
Ingo Molnar
198030782c Merge branch 'x86/mm' into core/percpu
Conflicts:
	arch/x86/mm/fault.c
2009-01-21 10:39:51 +01:00
Ingo Molnar
3eb3963fd1 Merge branch 'cpus4096' into core/percpu
Conflicts:
	arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
	arch/x86/kernel/tlb_32.c

Merge it here because both the cpumask changes and the ongoing percpu
work is touching the TLB code. The percpu changes take precedence, as
they eliminate tlb_32.c altogether.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-21 10:14:17 +01:00
Steven Rostedt
082605de5f ring-buffer: fix alignment problem
Impact: fix to allow some archs to use the ring buffer

Commits in the ring buffer are checked by pointer arithmetic.
If the calculation is incorrect, then the commits will never take
place and the buffer will simply fill up and report an error.

Each page in the ring buffer has a small header:

struct buffer_data_page {
	u64		time_stamp;
	local_t		commit;
	unsigned char	data[];
};

Unfortuntely, some of the calculations used sizeof(struct buffer_data_page)
to know the size of the header. But this is incorrect on some archs,
where sizeof(struct buffer_data_page) does not equal
offsetof(struct buffer_data_page, data), and on those archs, the commits
are never processed.

This patch replaces the sizeof with offsetof.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-20 13:09:06 +01:00
Rusty Russell
8ccad40df8 work_on_cpu: Use our own workqueue.
Impact: remove potential clashes with generic kevent workqueue

Annoyingly, some places we want to use work_on_cpu are already in
workqueues.  As per Ingo's suggestion, we create a different workqueue
for work_on_cpu.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-19 22:36:07 +01:00
Rusty Russell
31ad908120 work_on_cpu: don't try to get_online_cpus() in work_on_cpu.
Impact: remove potential circular lock dependency with cpu hotplug lock

This has caused more problems than it solved, with a pile of cpu
hotplug locking issues.

Followup patches will get_online_cpus() in callers that need it, but
if they don't do it they're no worse than before when they were using
set_cpus_allowed without locking.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-19 22:36:02 +01:00
Miao Xie
f90d4118ba cpuset: fix possible deadlock in async_rebuild_sched_domains
Lockdep reported some possible circular locking info when we tested cpuset on
NUMA/fake NUMA box.

=======================================================
[ INFO: possible circular locking dependency detected ]
2.6.29-rc1-00224-ga652504 #111
-------------------------------------------------------
bash/2968 is trying to acquire lock:
 (events){--..}, at: [<ffffffff8024c8cd>] flush_work+0x24/0xd8

but task is already holding lock:
 (cgroup_mutex){--..}, at: [<ffffffff8026ad1e>] cgroup_lock_live_group+0x12/0x29

which lock already depends on the new lock.
......
-------------------------------------------------------

Steps to reproduce:
# mkdir /dev/cpuset
# mount -t cpuset xxx /dev/cpuset
# mkdir /dev/cpuset/0
# echo 0 > /dev/cpuset/0/cpus
# echo 0 > /dev/cpuset/0/mems
# echo 1 > /dev/cpuset/0/memory_migrate
# cat /dev/zero > /dev/null &
# echo $! > /dev/cpuset/0/tasks

This is because async_rebuild_sched_domains has the following lock sequence:
run_workqueue(async_rebuild_sched_domains)
	-> do_rebuild_sched_domains -> cgroup_lock

But, attaching tasks when memory_migrate is set has following:
cgroup_lock_live_group(cgroup_tasks_write)
	-> do_migrate_pages -> flush_work

This patch fixes it by using a separate workqueue thread.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-19 02:44:00 +01:00
Peter Zijlstra
1d4a7f1c4f hrtimers: fix inconsistent lock state on resume in hres_timers_resume
Andrey Borzenkov reported this lockdep assert:

> [17854.688347] =================================
> [17854.688347] [ INFO: inconsistent lock state ]
> [17854.688347] 2.6.29-rc2-1avb #1
> [17854.688347] ---------------------------------
> [17854.688347] inconsistent {in-hardirq-W} -> {hardirq-on-W} usage.
> [17854.688347] pm-suspend/18240 [HC0[0]:SC0[0]:HE1:SE1] takes:
> [17854.688347]  (&cpu_base->lock){++..}, at: [<c0136fcc>] retrigger_next_event+0x5c/0xa0
> [17854.688347] {in-hardirq-W} state was registered at:
> [17854.688347]   [<c01443cd>] __lock_acquire+0x79d/0x1930
> [17854.688347]   [<c01455bc>] lock_acquire+0x5c/0x80
> [17854.688347]   [<c03092e5>] _spin_lock+0x35/0x70
> [17854.688347]   [<c0136e61>] hrtimer_run_queues+0x31/0x140
> [17854.688347]   [<c0128d98>] run_local_timers+0x8/0x20
> [17854.688347]   [<c0128dd3>] update_process_times+0x23/0x60
> [17854.688347]   [<c013e274>] tick_periodic+0x24/0x80
> [17854.688347]   [<c013e2e2>] tick_handle_periodic+0x12/0x70
> [17854.688347]   [<c0104e24>] timer_interrupt+0x14/0x20
> [17854.688347]   [<c01607b9>] handle_IRQ_event+0x29/0x60
> [17854.688347]   [<c0161c59>] handle_level_irq+0x69/0xe0
> [17854.688347]   [<ffffffff>] 0xffffffff
> [17854.688347] irq event stamp: 55771
> [17854.688347] hardirqs last  enabled at (55771): [<c0309125>] _spin_unlock_irqrestore+0x35/0x60
> [17854.688347] hardirqs last disabled at (55770): [<c0309419>] _spin_lock_irqsave+0x19/0x80
> [17854.688347] softirqs last  enabled at (54836): [<c0124f54>] __do_softirq+0xc4/0x110
> [17854.688347] softirqs last disabled at (54831): [<c01049ae>] do_softirq+0x8e/0xe0
> [17854.688347]
> [17854.688347] other info that might help us debug this:
> [17854.688347] 3 locks held by pm-suspend/18240:
> [17854.688347]  #0:  (&buffer->mutex){--..}, at: [<c01dd4c5>] sysfs_write_file+0x25/0x100
> [17854.688347]  #1:  (pm_mutex){--..}, at: [<c015056f>] enter_state+0x4f/0x140
> [17854.688347]  #2:  (dpm_list_mtx){--..}, at: [<c027880f>] device_pm_lock+0xf/0x20
> [17854.688347]
> [17854.688347] stack backtrace:
> [17854.688347] Pid: 18240, comm: pm-suspend Not tainted 2.6.29-rc2-1avb #1
> [17854.688347] Call Trace:
> [17854.688347]  [<c0306248>] ? printk+0x18/0x20
> [17854.688347]  [<c0141fac>] print_usage_bug+0x16c/0x1d0
> [17854.688347]  [<c0142bcf>] mark_lock+0x8bf/0xc90
> [17854.688347]  [<c0106b8f>] ? pit_next_event+0x2f/0x40
> [17854.688347]  [<c01441b0>] __lock_acquire+0x580/0x1930
> [17854.688347]  [<c030916d>] ? _spin_unlock+0x1d/0x20
> [17854.688347]  [<c0106b8f>] ? pit_next_event+0x2f/0x40
> [17854.688347]  [<c013dd38>] ? clockevents_program_event+0x98/0x160
> [17854.688347]  [<c0142fe8>] ? mark_held_locks+0x48/0x90
> [17854.688347]  [<c0309125>] ? _spin_unlock_irqrestore+0x35/0x60
> [17854.688347]  [<c0143229>] ? trace_hardirqs_on_caller+0x139/0x190
> [17854.688347]  [<c014328b>] ? trace_hardirqs_on+0xb/0x10
> [17854.688347]  [<c01455bc>] lock_acquire+0x5c/0x80
> [17854.688347]  [<c0136fcc>] ? retrigger_next_event+0x5c/0xa0
> [17854.688347]  [<c03092e5>] _spin_lock+0x35/0x70
> [17854.688347]  [<c0136fcc>] ? retrigger_next_event+0x5c/0xa0
> [17854.688347]  [<c0136fcc>] retrigger_next_event+0x5c/0xa0
> [17854.688347]  [<c013711a>] hres_timers_resume+0xa/0x10
> [17854.688347]  [<c013aa8e>] timekeeping_resume+0xee/0x150
> [17854.688347]  [<c0273384>] __sysdev_resume+0x14/0x50
> [17854.688347]  [<c0273407>] sysdev_resume+0x47/0x80
> [17854.688347]  [<c02791ab>] device_power_up+0xb/0x20
> [17854.688347]  [<c015043f>] suspend_devices_and_enter+0xcf/0x150
> [17854.688347]  [<c0150c2f>] ? freeze_processes+0x3f/0x90
> [17854.688347]  [<c0150614>] enter_state+0xf4/0x140
> [17854.688347]  [<c01506dd>] state_store+0x7d/0xc0
> [17854.688347]  [<c0150660>] ? state_store+0x0/0xc0
> [17854.688347]  [<c0202da4>] kobj_attr_store+0x24/0x30
> [17854.688347]  [<c01dd53c>] sysfs_write_file+0x9c/0x100
> [17854.688347]  [<c019916c>] vfs_write+0x9c/0x160
> [17854.688347]  [<c0103494>] ? restore_nocheck_notrace+0x0/0xe
> [17854.688347]  [<c01dd4a0>] ? sysfs_write_file+0x0/0x100
> [17854.688347]  [<c01992ed>] sys_write+0x3d/0x70
> [17854.688347]  [<c0103371>] sysenter_do_call+0x12/0x31

Andrey's analysis:

> timekeeping_resume() is called via class ->resume
> method; and according to comments in sysdev_resume() and
> device_power_up(), they are called with interrupts disabled.
>
> Looking at suspend_enter, irqs *are* disabled at this point.
>
> So it actually looks like something (may be some driver)
> unconditionally enabled irqs in resume path.

Add a debug check to test this theory. If it triggers then it
triggers because the resume code calls it with irqs enabled,
which is a no-no not just for timekeeping_resume(), but also
bad for a number of other resume handlers.

Reported-by: Andrey Borzenkov <arvidjaar@mail.ru>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-18 21:31:37 +01:00
Jiri Slaby
b786c6a98e relay: fix lock imbalance in relay_late_setup_files
One fail path in relay_late_setup_files() omits
mutex_unlock(&relay_channels_mutex);
Add it.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-18 20:29:35 +01:00
Ingo Molnar
b2b062b816 Merge branch 'core/percpu' into stackprotector
Conflicts:
	arch/x86/include/asm/pda.h
	arch/x86/include/asm/system.h

Also, moved include/asm-x86/stackprotector.h to arch/x86/include/asm.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-18 18:37:14 +01:00
Ingo Molnar
af37501c79 Merge branch 'core/percpu' into perfcounters/core
Conflicts:
	arch/x86/include/asm/pda.h

We merge tip/core/percpu into tip/perfcounters/core because of a
semantic and contextual conflict: the former eliminates the PDA,
while the latter extends it with apic_perf_irqs field.

Resolve the conflict by moving the new field to the irq_cpustat
structure on 64-bit too.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-18 18:15:49 +01:00
Paul Mackerras
d859e29fe3 perf_counter: Add counter enable/disable ioctls
Impact: New perf_counter features

This primarily adds a way for perf_counter users to enable and disable
counters and groups.  Enabling or disabling a counter or group also
enables or disables all of the child counters that have been cloned
from it to monitor children of the task monitored by the top-level
counter.  The userspace interface to enable/disable counters is via
ioctl on the counter file descriptor.

Along the way this extends the code that handles child counters to
handle child counter groups properly.  A group with multiple counters
will be cloned to child tasks if and only if the group leader has the
hw_event.inherit bit set - if it is set the whole group is cloned as a
group in the child task.

In order to be able to enable or disable all child counters of a given
top-level counter, we need a way to find them all.  Hence I have added
a child_list field to struct perf_counter, which is the head of the
list of children for a top-level counter, or the link in that list for
a child counter.  That list is protected by the perf_counter.mutex
field.

This also adds a mutex to the perf_counter_context struct.  Previously
the list of counters was protected just by the lock field in the
context, which meant that perf_counter_init_task had to take that lock
and then take whatever lock/mutex protects the top-level counter's
child_list.  But the counter enable/disable functions need to take
that lock in order to traverse the list, then for each counter take
the lock in that counter's context in order to change the counter's
state safely, which will lead to a deadlock.

To solve this, we now have both a mutex and a spinlock in the context,
and taking either is sufficient to ensure the list of counters can't
change - you have to take both before changing the list.  Now
perf_counter_init_task takes the mutex instead of the lock (which
incidentally means that inherit_counter can use GFP_KERNEL instead of
GFP_ATOMIC) and thus avoids the possible deadlock.  Similarly the new
enable/disable functions can take the mutex while traversing the list
of child counters without incurring a possible deadlock when the
counter manipulation code locks the context for a child counter.

We also had an misfeature that the first counter added to a context
would possibly not go on until the next sched-in, because we were
using ctx->nr_active to detect if the context was running on a CPU.
But nr_active is the number of active counters, and if that was zero
(because the context didn't have any counters yet) it would look like
the context wasn't running on a cpu and so the retry code in
__perf_install_in_context wouldn't retry.  So this adds an 'is_active'
field that is set when the context is on a CPU, even if it has no
counters.  The is_active field is only used for task contexts, not for
per-cpu contexts.

If we enable a subsidiary counter in a group that is active on a CPU,
and the arch code can't enable the counter, then we have to pull the
whole group off the CPU.  We do this with group_sched_out, which gets
moved up in the file so it comes before all its callers.  This also
adds similar logic to __perf_install_in_context so that the "all on,
or none" invariant of groups is preserved when adding a new counter to
a group.

Signed-off-by: Paul Mackerras <paulus@samba.org>
2009-01-17 18:10:22 +11:00
Rusty Russell
e1d9ec6246 work_on_cpu: Use our own workqueue.
Impact: remove potential clashes with generic kevent workqueue

Annoyingly, some places we want to use work_on_cpu are already in
workqueues.  As per Ingo's suggestion, we create a different workqueue
for work_on_cpu.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Mike Travis <travis@sgi.com>
2009-01-16 15:31:15 -08:00
Rusty Russell
68564a4697 work_on_cpu: don't try to get_online_cpus() in work_on_cpu.
Impact: remove potential circular lock dependency with cpu hotplug lock

This has caused more problems than it solved, with a pile of cpu
hotplug locking issues.

Followup patches will get_online_cpus() in callers that need it, but
if they don't do it they're no worse than before when they were using
set_cpus_allowed without locking.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Mike Travis <travis@sgi.com>
2009-01-16 15:31:15 -08:00
Rafael J. Wysocki
091d71e023 PM: Fix compilation warning in kernel/power/main.c
Reorder the code in kernel/power/main.c to fix compilation warning
triggered by unsetting CONFIG_SUSPEND.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
2009-01-16 18:13:41 -05:00
Len Brown
88d998c264 Merge branch 'misc' into release 2009-01-16 14:45:34 -05:00
Masami Hiramatsu
5a4ccaf37f kprobes: check CONFIG_FREEZER instead of CONFIG_PM
Check CONFIG_FREEZER instead of CONFIG_PM because kprobe booster
depends on freeze_processes() and thaw_processes() when CONFIG_PREEMPT=y.

This fixes a linkage error which occurs when CONFIG_PREEMPT=y, CONFIG_PM=y
and CONFIG_FREEZER=n.

Reported-by: Cheng Renquan <crquan@gmail.com>
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Len Brown <len.brown@intel.com>
2009-01-16 14:32:17 -05:00
Rafael J. Wysocki
33f1d7ecc6 PM: Fix freezer compilation if PM_SLEEP is unset
Freezer fails to compile if with the following configuration
settings:

CONFIG_CGROUPS=y
CONFIG_CGROUP_FREEZER=y
CONFIG_MODULES=y
CONFIG_FREEZER=y
CONFIG_PM=y
CONFIG_PM_SLEEP=n

Fix this by making process.o compilation depend on CONFIG_FREEZER.

Reported-by: Cheng Renquan <crquan@gmail.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Len Brown <len.brown@intel.com>
2009-01-16 14:32:17 -05:00
Linus Torvalds
7cb36b6ccd Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched: sched_slice() fixlet
  sched: fix update_min_vruntime
  sched: SCHED_OTHER vs SCHED_IDLE isolation
  sched: SCHED_IDLE weight change
  sched: fix bandwidth validation for UID grouping
  Revert "sched: improve preempt debugging"
2009-01-15 16:55:00 -08:00
Randy Dunlap
6ae301e85c resources: fix parameter name and kernel-doc
Fix __request_region() parameter kernel-doc notation and parameter name:

Warning(linux-2.6.28-git10//kernel/resource.c:627): No description found for parameter 'flags'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-15 16:39:38 -08:00
Li Zefan
45ce80fb6b cgroups: consolidate cgroup documents
Move Documentation/cpusets.txt and Documentation/controllers/* to
Documentation/cgroups/

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-15 16:39:37 -08:00
Lin Ming
6272d68cc6 sched: sched_slice() fixlet
Mike's change: 0a582440f "sched: fix sched_slice())" broke group
scheduling by forgetting to reload cfs_rq on each loop.

This patch fixes aim7 regression and specjbb2005 regression becomes
less than 1.5% on 8-core stokley.

Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Tested-by: Jayson King <dev@jaysonking.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-15 21:07:57 +01:00
Doug Chapman
88fc241f54 [IA64] dump stack on kernel unaligned warnings
Often the cause of kernel unaligned access warnings is not
obvious from just the ip displayed in the warning.  This adds
the option via proc to dump the stack in addition to the warning.
The default is off (just display the 1 line warning).  To enable
the stack to be shown: echo 1 > /proc/sys/kernel/unaligned-dump-stack

Signed-off-by: Doug Chapman <doug.chapman@hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2009-01-15 10:38:56 -08:00
Ingo Molnar
49a93bc978 Merge branch 'linus' into cpus4096 2009-01-15 15:45:31 +01:00
Peter Zijlstra
e17036dac1 sched: fix update_min_vruntime
Impact: fix SCHED_IDLE latency problems

OK, so we have 1 running task A (which is obviously curr and the tree is
equally obviously empty).

'A' nicely chugs along, doing its thing, carrying min_vruntime along as it
goes.

Then some whacko speed freak SCHED_IDLE task gets inserted due to SMP
balancing, which is very likely far right, in that case

update_curr
  update_min_vruntime
    cfs_rq->rb_leftmost := true (the crazy task sitting in a tree)
      vruntime = se->vruntime

and voila, min_vruntime is waaay right of where it ought to be.

OK, so why did I write it like that to begin with...

Aah, yes.

Say we've just dequeued current

schedule
  deactivate_task(prev)
    dequeue_entity
      update_min_vruntime

Then we'll set

  vruntime = cfs_rq->min_vruntime;

we find !cfs_rq->curr, but do find someone in the tree. Then we _must_
do vruntime = se->vruntime, because

 vruntime = min_vruntime(vruntime := cfs_rq->min_vruntime, se->vruntime)

will not advance vruntime, and cause lags the other way around (which we
fixed with that initial patch: 1af5f730fc
(sched: more accurate min_vruntime accounting).

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Tested-by: Mike Galbraith <efault@gmx.de>
Acked-by: Mike Galbraith <efault@gmx.de>
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-15 15:12:19 +01:00
Peter Zijlstra
6bc912b71b sched: SCHED_OTHER vs SCHED_IDLE isolation
Stronger SCHED_IDLE isolation:

 - no SCHED_IDLE buddies
 - never let SCHED_IDLE preempt on wakeup
 - always preempt SCHED_IDLE on wakeup
 - limit SLEEPER fairness for SCHED_IDLE.

Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-15 15:07:29 +01:00
Peter Zijlstra
cce7ade803 sched: SCHED_IDLE weight change
Increase the SCHED_IDLE weight from 2 to 3, this gives much more stable
vruntime numbers.

time advanced in 100ms:

 weight=2

 64765.988352
 67012.881408
 88501.412352

 weight=3

 35496.181411
 34130.971298
 35497.411573

Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-15 15:07:28 +01:00
Peter Zijlstra
98a4826b99 sched: fix bandwidth validation for UID grouping
Impact: make rt-limit tunables work again

Mark Glines reported:

> I've got an issue on x86-64 where I can't configure the system to allow
> RT tasks for a non-root user.
>
> In 2.6.26.5, I was able to do the following to set things up nicely:
> echo 450000 >/sys/kernel/uids/0/cpu_rt_runtime
> echo 450000 >/sys/kernel/uids/1000/cpu_rt_runtime
>
> Seems like every value I try to echo into the /sys files returns EINVAL.

For UID grouping we initialize the root group with infinite bandwidth
which by default is actually more than the global limit, therefore the
bandwidth check always fails.

Because the root group is a phantom group (for UID grouping) we cannot
runtime adjust it, therefore we let it reflect the global bandwidth
settings.

Reported-by: Mark Glines <mark@glines.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-15 15:07:27 +01:00
Ingo Molnar
7f268f4352 Merge branches 'cpus4096', 'x86/cleanups' and 'x86/urgent' into x86/percpu 2009-01-15 13:18:57 +01:00
Jaswinder Singh Rajput
934d96eafa time-sched.c: tick_nohz_update_jiffies should be static
Impact: cleanup, reduce kernel size a bit, avoid sparse warning

Fixes sparse warning:

 kernel/time/tick-sched.c:137:6: warning: symbol 'tick_nohz_update_jiffies' was not declared. Should it be static?

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-15 12:06:56 +01:00
Linus Torvalds
bca268565f Merge branch 'syscalls' of git://git390.osdl.marist.edu/pub/scm/linux-2.6
* 'syscalls' of git://git390.osdl.marist.edu/pub/scm/linux-2.6: (44 commits)
  [CVE-2009-0029] s390 specific system call wrappers
  [CVE-2009-0029] System call wrappers part 33
  [CVE-2009-0029] System call wrappers part 32
  [CVE-2009-0029] System call wrappers part 31
  [CVE-2009-0029] System call wrappers part 30
  [CVE-2009-0029] System call wrappers part 29
  [CVE-2009-0029] System call wrappers part 28
  [CVE-2009-0029] System call wrappers part 27
  [CVE-2009-0029] System call wrappers part 26
  [CVE-2009-0029] System call wrappers part 25
  [CVE-2009-0029] System call wrappers part 24
  [CVE-2009-0029] System call wrappers part 23
  [CVE-2009-0029] System call wrappers part 22
  [CVE-2009-0029] System call wrappers part 21
  [CVE-2009-0029] System call wrappers part 20
  [CVE-2009-0029] System call wrappers part 19
  [CVE-2009-0029] System call wrappers part 18
  [CVE-2009-0029] System call wrappers part 17
  [CVE-2009-0029] System call wrappers part 16
  [CVE-2009-0029] System call wrappers part 15
  ...
2009-01-14 19:58:40 -08:00
Sam Ravnborg
2ea038917b Revert "kbuild: strip generated symbols from *.ko"
This reverts commit ad7a953c52.

And commit: ("allow stripping of generated symbols under CONFIG_KALLSYMS_ALL")
            9bb482476c

These stripping patches has caused a set of issues:

1) People have reported compatibility issues with binutils due to
   lack of support for `--strip-unneeded-symbols' with objcopy 2.15.92.0.2
   Reported by: Wenji
2) ccache and distcc no longer works as expeced
   Reported by: Ted, Roland, + others
3) The installed modules increased a lot in size
   Reported by: Ted, Davej + others

Reported-by: Wenji Huang <wenji.huang@oracle.com>
Reported-by: "Theodore Ts'o" <tytso@mit.edu>
Reported-by: Dave Jones <davej@redhat.com>
Reported-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2009-01-14 21:38:20 +01:00
Andrew Morton
9316fcacb8 kernel/up.c: omit it if SMP=y, USE_GENERIC_SMP_HELPERS=n
Fix the sparc build - we were including `up.o' on SMP builds, when
CONFIG_USE_GENERIC_SMP_HELPERS=n.

Tested-by: Robert Reif <reif@earthlink.net>
Fixed-by: Robert Reif <reif@earthlink.net>
Cc: David Miller <davem@davemloft.net>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-14 09:42:11 -08:00
Heiko Carstens
d4e82042c4 [CVE-2009-0029] System call wrappers part 32
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 14:15:31 +01:00
Heiko Carstens
836f92adf1 [CVE-2009-0029] System call wrappers part 31
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 14:15:31 +01:00
Heiko Carstens
6559eed8ca [CVE-2009-0029] System call wrappers part 30
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 14:15:30 +01:00
Heiko Carstens
1e7bfb2134 [CVE-2009-0029] System call wrappers part 27
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 14:15:29 +01:00
Heiko Carstens
c4ea37c26a [CVE-2009-0029] System call wrappers part 26
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 14:15:29 +01:00
Heiko Carstens
e48fbb699f [CVE-2009-0029] System call wrappers part 24
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 14:15:28 +01:00
Heiko Carstens
5a8a82b1d3 [CVE-2009-0029] System call wrappers part 23
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 14:15:28 +01:00
Heiko Carstens
003d7ab479 [CVE-2009-0029] System call wrappers part 19
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 14:15:26 +01:00
Heiko Carstens
a6b42e83f2 [CVE-2009-0029] System call wrappers part 18
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 14:15:25 +01:00
Heiko Carstens
ca013e945b [CVE-2009-0029] System call wrappers part 17
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 14:15:25 +01:00
Heiko Carstens
a5f8fa9e9b [CVE-2009-0029] System call wrappers part 09
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 14:15:21 +01:00
Heiko Carstens
17da2bd90a [CVE-2009-0029] System call wrappers part 08
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 14:15:21 +01:00
Heiko Carstens
754fe8d297 [CVE-2009-0029] System call wrappers part 07
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 14:15:20 +01:00
Heiko Carstens
5add95d4f7 [CVE-2009-0029] System call wrappers part 06
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 14:15:20 +01:00
Heiko Carstens
362e9c07c7 [CVE-2009-0029] System call wrappers part 05
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 14:15:20 +01:00
Heiko Carstens
b290ebe2c4 [CVE-2009-0029] System call wrappers part 04
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 14:15:19 +01:00
Heiko Carstens
ae1251ab78 [CVE-2009-0029] System call wrappers part 03
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 14:15:19 +01:00
Heiko Carstens
dbf040d9d1 [CVE-2009-0029] System call wrappers part 02
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 14:15:19 +01:00
Heiko Carstens
58fd3aa288 [CVE-2009-0029] System call wrappers part 01
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 14:15:18 +01:00
Heiko Carstens
f627a741d2 [CVE-2009-0029] Make sys_syslog a conditional system call
Remove the -ENOSYS implementation for !CONFIG_PRINTK and use
the cond_syscall infrastructure instead.

Acked-by: Kyle McMartin <kyle@redhat.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 14:15:16 +01:00
Heiko Carstens
2ed7c03ec1 [CVE-2009-0029] Convert all system calls to return a long
Convert all system calls to return a long. This should be a NOP since all
converted types should have the same size anyway.
With the exception of sys_exit_group which returned void. But that doesn't
matter since the system call doesn't return.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 14:15:14 +01:00
Ingo Molnar
14819ea1e0 irq: export __set_irq_handler() and handle_level_irq()
Impact: build fix

ARM updates broke x86 allmodconfig builds:

 ERROR: "__set_irq_handler" [drivers/mfd/pcf50633-core.ko] undefined!
 ERROR: "handle_level_irq" [drivers/mfd/pcf50633-core.ko] undefined!

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-14 12:34:21 +01:00
Mandeep Singh Baines
baf48f6577 softlock: fix false panic which can occur if softlockup_thresh is reduced
At run-time, if softlockup_thresh is changed to a much lower value,
touch_timestamp is likely to be much older than the new softlock_thresh.

This will cause a false softlockup to be detected. If softlockup_panic
is enabled, the system will panic.

The fix is to touch all watchdogs before changing softlockup_thresh.

Signed-off-by: Mandeep Singh Baines <msb@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-14 11:48:07 +01:00
Lai Jiangshan
e4fa4c9701 rcu: add __cpuinit to rcu_init_percpu_data()
Impact: reduce memory footprint

add __cpuinit to rcu_init_percpu_data(), and this function's text
will be discarded after boot when !CONFIG_HOTPLUG_CPU.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-14 11:26:40 +01:00
Paul Mackerras
3b6f9e5cb2 perf_counter: Add support for pinned and exclusive counter groups
Impact: New perf_counter features

A pinned counter group is one that the user wants to have on the CPU
whenever possible, i.e. whenever the associated task is running, for
a per-task group, or always for a per-cpu group.  If the system
cannot satisfy that, it puts the group into an error state where
it is not scheduled any more and reads from it return EOF (i.e. 0
bytes read).  The group can be released from error state and made
readable again using prctl(PR_TASK_PERF_COUNTERS_ENABLE).  When we
have finer-grained enable/disable controls on counters we'll be able
to reset the error state on individual groups.

An exclusive group is one that the user wants to be the only group
using the CPU performance monitor hardware whenever it is on.  The
counter group scheduler will not schedule an exclusive group if there
are already other groups on the CPU and will not schedule other groups
onto the CPU if there is an exclusive group scheduled (that statement
does not apply to groups containing only software counters, which can
always go on and which do not prevent an exclusive group from going on).
With an exclusive group, we will be able to let users program PMU
registers at a low level without the concern that those settings will
perturb other measurements.

Along the way this reorganizes things a little:
- is_software_counter() is moved to perf_counter.h.
- cpuctx->active_oncpu now records the number of hardware counters on
  the CPU, i.e. it now excludes software counters.  Nothing was reading
  cpuctx->active_oncpu before, so this change is harmless.
- A new cpuctx->exclusive field records whether we currently have an
  exclusive group on the CPU.
- counter_sched_out moves higher up in perf_counter.c and gets called
  from __perf_counter_remove_from_context and __perf_counter_exit_task,
  where we used to have essentially the same code.
- __perf_counter_sched_in now goes through the counter list twice, doing
  the pinned counters in the first loop and the non-pinned counters in
  the second loop, in order to give the pinned counters the best chance
  to be scheduled in.

Note that only a group leader can be exclusive or pinned, and that
attribute applies to the whole group.  This avoids some awkwardness in
some corner cases (e.g. where a group leader is closed and the other
group members get added to the context list).  If we want to relax that
restriction later, we can, and it is easier to relax a restriction than
to apply a new one.

This doesn't yet handle the case where a pinned counter is inherited
and goes into error state in the child - the error state is not
propagated up to the parent when the child exits, and arguably it
should.

Signed-off-by: Paul Mackerras <paulus@samba.org>
2009-01-14 21:00:30 +11:00
Paul Mackerras
01d0287f06 powerpc/perf_counter: Make sure PMU gets enabled properly
This makes sure that we call the platform-specific ppc_md.enable_pmcs
function on each CPU before we try to use the PMU on that CPU.  If the
CPU goes off-line and then on-line, we need to do the enable_pmcs call
again, so we use the hw_perf_counter_setup hook to ensure that.  It gets
called as each CPU comes online, but it isn't called on the CPU that is
coming up, so this adds the CPU number as an argument to it (there were
no non-empty instances of hw_perf_counter_setup before).

This also arranges to set the pmcregs_in_use field of the lppaca (data
structure shared with the hypervisor) on each CPU when we are using the
PMU and clear it when we are not.  This allows the hypervisor to optimize
partition switches by not saving/restoring the PMU registers when we
aren't using the PMU.

Signed-off-by: Paul Mackerras <paulus@samba.org>
2009-01-14 13:44:19 +11:00
Linus Torvalds
28839855bf Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  smp_call_function_single(): be slightly less stupid, fix #2
  lockdep, mm: fix might_fault() annotation
2009-01-13 09:02:21 -08:00
Yinghai Lu
4a046d1754 x86: arch_probe_nr_irqs
Impact: save RAM with large NR_CPUS, get smaller nr_irqs

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Mike Travis <travis@sgi.com>
2009-01-12 17:39:24 -08:00
Arjan van de Ven
37a76bd4f1 async: fix __lowest_in_progress()
At 37000 feet somewhere near Greenland I woke up from a half-sleep with the
realisation that __lowest_in_progress() is buggy. After landing I checked
and there were indeed 2 problems with it; this patch fixes both:
* The order of the list checks was wrong
* The locking was not correct.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-12 16:39:58 -08:00
Linus Torvalds
12847095e9 Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  kernel/sched.c: add missing forward declaration for 'double_rq_lock'
  sched: partly revert "sched debug: remove NULL checking in print_cfs_rt_rq()"
  cpumask: fix CONFIG_NUMA=y sched.c
2009-01-12 16:29:00 -08:00
Ingo Molnar
6e96281412 smp_call_function_single(): be slightly less stupid, fix #2
fix m68k build failure:

 tip/kernel/up.c: In function 'smp_call_function_single':
 tip/kernel/up.c:16: error: dereferencing pointer to incomplete type
 make[2]: *** [kernel/up.o] Error 1

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-12 16:04:37 +01:00
Ingo Molnar
01e3eb8227 Revert "sched: improve preempt debugging"
This reverts commit 7317d7b87e.

This has been reported (and bisected) by Alexey Zaytsev and
Kamalesh Babulal to produce annoying warnings during bootup
on both x86 and powerpc.

kernel_locked() is not a valid test in IRQ context (we update the
BKL's ->lock_depth and the preempt count separately and non-atomicalyy),
so we cannot put it into the generic preempt debugging checks which
can run in IRQ contexts too.

Reported-and-bisected-by: Alexey Zaytsev <alexey.zaytsev@gmail.com>
Reported-and-bisected-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-12 13:00:50 +01:00
Paul Mackerras
dd0e6ba22e perf_counter: Always schedule all software counters in
Software counters aren't subject to the limitations imposed by the
fixed number of hardware counter registers, so there is no reason not
to enable them all in __perf_counter_sched_in.  Previously we used to
break out of the loop when we got to a group that wouldn't fit on the
PMU; with this we continue through the list but only schedule in
software counters (or groups containing only software counters) from
there on.

Signed-off-by: Paul Mackerras <paulus@samba.org>
2009-01-12 15:12:50 +11:00
Mike Travis
92296c6d6e cpumask, irq: non-x86 build failures
Ingo Molnar wrote:

> All non-x86 architectures fail to build:
>
> In file included from /home/mingo/tip/include/linux/random.h:11,
>                  from /home/mingo/tip/include/linux/stackprotector.h:6,
>                  from /home/mingo/tip/init/main.c:17:
> /home/mingo/tip/include/linux/irqnr.h:26:63: error: asm/irq_vectors.h: No such file or directory

Do not include asm/irq_vectors.h in generic code - it's not available
on all architectures.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-11 19:13:45 +01:00
Mike Travis
542d865bbe kstat: modify kstat_irqs_legacy to be variable sized
Impact: reduce memory usage.

Allocate kstat_irqs_legacy based on nr_cpu_ids to deal with this
memory usage bump when NR_CPUS bumped from 128 to 4096:

     8192   +253952    262144 +3100%  kstat_irqs_legacy(.bss)

This is only when CONFIG_SPARSE_IRQS=y.

Signed-off-by: Mike Travis <travis@sgi.com>
2009-01-11 19:13:42 +01:00
Mike Travis
9332fccded irq: initialize nr_irqs based on nr_cpu_ids
Impact: Reduce memory usage.

This is the second half of the changes to make the irq_desc_ptrs be
variable sized based on nr_cpu_ids.  This is done by adding a new
"max_nr_irqs" macro to irq_vectors.h (and a dummy in irqnr.h) to
return a max NR_IRQS value based on NR_CPUS or nr_cpu_ids.

This necessitated moving the define of MAX_IO_APICS to a separate
file (asm/apicnum.h) so it could be included without the baggage
of the other asm/apicdef.h declarations.

Signed-off-by: Mike Travis <travis@sgi.com>
2009-01-11 19:13:38 +01:00
Mike Travis
0fa0ebbf15 irq: allocate irq_desc_ptrs array based on nr_irqs
Impact: allocate irq_desc_ptrs in preparation for making it variable-sized.

This addresses this memory usage bump when NR_CPUS bumped from 128 to 4096:

    34816   +229376    264192  +658%  irq_desc_ptrs(.data.read_mostly)

The patch is split into two parts, the first simply allocates the
irq_desc_ptrs array.  Then next will deal with making it variable.
This is only when CONFIG_SPARSE_IRQS=y.

Signed-off-by: Mike Travis <travis@sgi.com>
2009-01-11 19:13:35 +01:00
Mike Travis
e2f4d06545 irq: use WARN() instead of WARN_ON().
Impact: cleanup WARN msg.

Ingo requested:
> While at it, could you please also convert this to a WARN() construct
> instead? (in a separate commit)

... and it shall be done.  ;-)

Signed-off-by: Mike Travis <travis@sgi.com>
2009-01-11 19:13:32 +01:00
Mike Travis
9594949b06 irq: change references from NR_IRQS to nr_irqs
Impact: preparation, cleanup, add KERN_INFO printk

Modify references from NR_IRQS to nr_irqs as the later will become
variable-sized based on nr_cpu_ids when CONFIG_SPARSE_IRQS=y.

Signed-off-by: Mike Travis <travis@sgi.com>
2009-01-11 19:13:29 +01:00
Mike Travis
d38b223c86 cpumask: reduce stack usage in find_lowest_rq
Impact: reduce stack usage, cleanup

Use a cpumask_var_t in find_lowest_rq() and clean up other old
cpumask_t calls.

Signed-off-by: Mike Travis <travis@sgi.com>
2009-01-11 19:13:22 +01:00
Mike Travis
802bf931f2 cpumask: fix bug in use cpumask_var_t in irq_desc
Impact: fix bug where new irq_desc uses old cpumask pointers which are freed.

As Yinghai pointed out, init_copy_one_irq_desc() copies the old desc to
the new desc overwriting the cpumask pointers.  Since the old_desc and
the cpumask pointers are freed, then memory corruption will occur if
these old pointers are used.

Move the allocation of these pointers to after the copy.

Signed-off-by: Mike Travis <travis@sgi.com>
Cc: Yinghai Lu <yinghai@kernel.org>
2009-01-11 19:13:02 +01:00
Mike Travis
7f7ace0cda cpumask: update irq_desc to use cpumask_var_t
Impact: reduce memory usage, use new cpumask API.

Replace the affinity and pending_masks with cpumask_var_t's.  This adds
to the significant size reduction done with the SPARSE_IRQS changes.

The added functions (init_alloc_desc_masks & init_copy_desc_masks) are
in the include file so they can be inlined (and optimized out for the
!CONFIG_CPUMASKS_OFFSTACK case.)  [Naming chosen to be consistent with
the other init*irq functions, as well as the backwards arg declaration
of "from, to" instead of the more common "to, from" standard.]

Includes a slight change to the declaration of struct irq_desc to embed
the pending_mask within ifdef(CONFIG_SMP) to be consistent with other
references, and some small changes to Xen.

Tested: sparse/non-sparse/cpumask_offstack/non-cpumask_offstack/nonuma/nosmp on x86_64

Signed-off-by: Mike Travis <travis@sgi.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: virtualization@lists.osdl.org
Cc: xen-devel@lists.xensource.com
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
2009-01-11 19:12:46 +01:00
Steven Noonan
783adf42cf kernel/fork.c: unused variable 'ret'
Removed the unused variable.

Signed-off-by: Steven Noonan <steven@uplinklabs.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-11 15:34:10 +01:00
Ingo Molnar
d19b85db9d Merge commit 'v2.6.29-rc1' into timers/urgent 2009-01-11 15:34:05 +01:00
Steven Noonan
fd2ab30b65 kernel/sched.c: add missing forward declaration for 'double_rq_lock'
Impact: build fix on certain configs

Added 'double_rq_lock' forward declaration, allowing double_rq_lock
to be used in _double_lock_balance().

Signed-off-by: Steven Noonan <steven@uplinklabs.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-11 13:06:07 +01:00
Ingo Molnar
93423b8665 smp_call_function_single(): be slightly less stupid, fix
Impact: build fix on Alpha

 kernel/up.c: In function 'smp_call_function_single':
 kernel/up.c:12: error: 'cpuid' undeclared (first use in this function)
 kernel/up.c:12: error: (Each undeclared identifier is reported only once
 kernel/up.c:12: error: for each function it appears in.)

The typo didnt show up on x86 because 'cpuid' happens to be a
function address as well ...

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-11 05:15:21 +01:00
Andrew Morton
53ce3d9564 smp_call_function_single(): be slightly less stupid
If you do

	smp_call_function_single(expression-with-side-effects, ...)

then expression-with-side-effects never gets evaluated on UP builds.

As always, implementing it in C is the correct thing to do.

While we're there, uninline it for size and possible header dependency
reasons.

And create a new kernel/up.c, as a place in which to put
uniprocessor-specific code and storage.  It should mirror kernel/smp.c.

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-11 03:41:58 +01:00
Ingo Molnar
abede81c4f Merge commit 'v2.6.29-rc1' into core/urgent 2009-01-11 03:41:39 +01:00
Ingo Molnar
c0d362a832 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/perfcounters into perfcounters/core 2009-01-11 02:44:08 +01:00
Ingo Molnar
506c10f26c Merge commit 'v2.6.29-rc1' into perfcounters/core
Conflicts:
	include/linux/kernel_stat.h
2009-01-11 02:42:53 +01:00
Li Zefan
805194c35b sched: partly revert "sched debug: remove NULL checking in print_cfs_rt_rq()"
Impact: avoid accessing NULL tg.css->cgroup

In commit 0a0db8f5c9, I removed checking
NULL tg.css->cgroup, but I realized I was wrong when I found reading
/proc/sched_debug can race with cgroup_create().

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-11 02:40:32 +01:00
Rusty Russell
62ea9ceb17 cpumask: fix CONFIG_NUMA=y sched.c
Impact: fix panic on ia64 with NR_CPUS=1024

struct sched_domain is now a dangling structure; where we really want
static ones, we need to use static_sched_domain.

(As the FIXME in this file says, cpumask_var_t would be better, but
this code is hairy enough without trying to add initialization code to
the right places).

Reported-by: Mike Travis <travis@sgi.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-11 01:04:16 +01:00
Linus Torvalds
9a100a4464 Merge git://git.kernel.org/pub/scm/linux/kernel/git/arjan/linux-2.6-async-2
* git://git.kernel.org/pub/scm/linux/kernel/git/arjan/linux-2.6-async-2:
  async: make async a command line option for now
  partial revert of asynchronous inode delete
2009-01-09 15:32:26 -08:00
Linus Torvalds
c40f6f8bbc Merge git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-2.6-nommu
* git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-2.6-nommu:
  NOMMU: Support XIP on initramfs
  NOMMU: Teach kobjsize() about VMA regions.
  FLAT: Don't attempt to expand the userspace stack to fill the space allocated
  FDPIC: Don't attempt to expand the userspace stack to fill the space allocated
  NOMMU: Improve procfs output using per-MM VMAs
  NOMMU: Make mmap allocation page trimming behaviour configurable.
  NOMMU: Make VMAs per MM as for MMU-mode linux
  NOMMU: Delete askedalloc and realalloc variables
  NOMMU: Rename ARM's struct vm_region
  NOMMU: Fix cleanup handling in ramfs_nommu_get_umapped_area()
2009-01-09 14:00:58 -08:00
Linus Torvalds
1a7d0f0bec Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6:
  CRED: Fix commit_creds() on a process that has no mm
2009-01-09 13:59:25 -08:00
Arjan van de Ven
cdb80f630b async: make async a command line option for now
... and have it default off.
This does allow people to work with it for testing.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
2009-01-09 13:23:45 -08:00
Linus Torvalds
4ce5f24193 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rric/oprofile
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rric/oprofile: (31 commits)
  powerpc/oprofile: fix whitespaces in op_model_cell.c
  powerpc/oprofile: IBM CELL: add SPU event profiling support
  powerpc/oprofile: fix cell/pr_util.h
  powerpc/oprofile: IBM CELL: cleanup and restructuring
  oprofile: make new cpu buffer functions part of the api
  oprofile: remove #ifdef CONFIG_OPROFILE_IBS in non-ibs code
  ring_buffer: fix ring_buffer_event_length()
  oprofile: use new data sample format for ibs
  oprofile: add op_cpu_buffer_get_data()
  oprofile: add op_cpu_buffer_add_data()
  oprofile: rework implementation of cpu buffer events
  oprofile: modify op_cpu_buffer_read_entry()
  oprofile: add op_cpu_buffer_write_reserve()
  oprofile: rename variables in add_ibs_begin()
  oprofile: rename add_sample() in cpu_buffer.c
  oprofile: rename variable ibs_allowed to has_ibs in op_model_amd.c
  oprofile: making add_sample_entry() inline
  oprofile: remove backtrace code for ibs
  oprofile: remove unused ibs macro
  oprofile: remove unused components in struct oprofile_cpu_buffer
  ...
2009-01-09 12:43:06 -08:00
Linus Torvalds
a3a798c88a Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6: (94 commits)
  ACPICA: hide private headers
  ACPICA: create acpica/ directory
  ACPI: fix build warning
  ACPI : Use RSDT instead of XSDT by adding boot option of "acpi=rsdt"
  ACPI: Avoid array address overflow when _CST MWAIT hint bits are set
  fujitsu-laptop: Simplify SBLL/SBL2 backlight handling
  fujitsu-laptop: Add BL power, LED control and radio state information
  ACPICA: delete utcache.c
  ACPICA: delete acdisasm.h
  ACPICA: Update version to 20081204.
  ACPICA: FADT: Update error msgs for consistency
  ACPICA: FADT: set acpi_gbl_use_default_register_widths to TRUE by default
  ACPICA: FADT parsing changes and fixes
  ACPICA: Add ACPI_MUTEX_TYPE configuration option
  ACPICA: Fixes for various ACPI data tables
  ACPICA: Restructure includes into public/private
  ACPI: remove private acpica headers from driver files
  ACPI: reboot.c: use new acpi_reset interface
  ACPICA: New: acpi_reset interface - write to reset register
  ACPICA: Move all public H/W interfaces to new hwxface
  ...
2009-01-09 11:55:14 -08:00
David Howells
43529c9712 CRED: Must initialise the new creds in prepare_kernel_cred()
The newly allocated creds in prepare_kernel_cred() must be initialised
before get_uid() and get_group_info() can access them.  They should be
copied from the old credentials.

Reported-by: Steve Dickson <steved@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Steve Dickson <steved@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-09 11:53:53 -08:00
David Howells
0de3368141 CRED: Missing put_cred() in prepare_kernel_cred()
Missing put_cred() in the error handling path of prepare_kernel_cred().

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Steve Dickson <steved@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-09 11:53:53 -08:00
Len Brown
b2576e1d44 Merge branch 'linus' into release 2009-01-09 03:39:43 -05:00
Len Brown
3cc8a5f4ba Merge branch 'suspend' into release 2009-01-09 03:38:15 -05:00
Paul Mackerras
4eb96fcfe0 perf_counter: Add dummy perf_counter_print_debug function
Impact: minimize requirements on architectures

Currently, an architecture just enabling CONFIG_PERF_COUNTERS but not
providing any extra functions will fail to build with
perf_counter_print_debug being undefined, since we don't provide an
empty dummy definition like we do with the hw_perf_* functions.

This provides an empty dummy perf_counter_print_debug() to make it
easier for architectures to turn on CONFIG_PERF_COUNTERS.

Signed-off-by: Paul Mackerras <paulus@samba.org>
2009-01-09 17:24:34 +11:00
Paul Mackerras
3cbed429a9 perf_counter: Add optional hw_perf_group_sched_in arch function
Impact: extend perf_counter infrastructure

This adds an optional hw_perf_group_sched_in() arch function that enables
a whole group of counters in one go.  It returns 1 if it added the group
successfully, 0 if it did nothing (and therefore the core needs to add
the counters individually), or a negative number if an error occurred.
It should add all the counters and enable any software counters in the
group, or else add none of them and return an error.

There are a couple of related changes/improvements in the group handling
here:

* As an optimization, group_sched_out() and group_sched_in() now check the
  state of the group leader, and do nothing if the leader is not active
  or disabled.

* We now call hw_perf_save_disable/hw_perf_restore around the complete
  set of counter enable/disable calls in __perf_counter_sched_in/out,
  to give the arch code the opportunity to defer updating the hardware
  state until the hw_perf_restore call if it wants.

* We no longer stop adding groups after we get to a group that has more
  than one counter.  We will ultimately add an option for a group to be
  exclusive.  The current code doesn't really implement exclusive groups
  anyway, since a group could end up going on with other counters that
  get added before it.

Signed-off-by: Paul Mackerras <paulus@samba.org>
2009-01-09 16:43:42 +11:00
Paul Mackerras
9abf8a08bc perf_counter: Fix the cpu_clock software counter
Impact: bug fix

Currently if you do (e.g.) timec -e -1 ls, it will report 0 for the
value of the cpu_clock counter.  The reason is that the core assumes
that a counter's count field is up-to-date when the counter is inactive,
and doesn't call the counter's read function.  However, the cpu_clock
counter code only updates the count in the read function.

This fixes it by making both the read and disable functions update the
count.  It also makes the counter ignore time passing while the counter
is disabled, by making the enable function update the hw.prev_count field.

Signed-off-by: Paul Mackerras <paulus@samba.org>
2009-01-09 16:26:43 +11:00
Paul Mackerras
ff6f05416e perf_counter: Fix return value from dummy hw_perf_counter_init
Impact: fix oops-causing bug

Currently, if you try to use perf_counters on an architecture that has
no hardware support, and you select an event that doesn't map to any of
the defined software counters, you get an oops rather than an error.
This is because the dummy hw_perf_counter_init returns ERR_PTR(-EINVAL)
but the caller (perf_counter_alloc) only tests for NULL.

This makes the dummy hw_perf_counter_init return NULL instead.

Signed-off-by: Paul Mackerras <paulus@samba.org>
2009-01-09 16:19:25 +11:00
Arjan van de Ven
33b04b9308 async: make async_synchronize_full() more serializing
turns out that there are real problems with allowing async
tasks that are scheduled from async tasks to run after
the async_synchronize_full() returns.

This patch makes the _full more strict and a complete
synchronization. Later I might need to add back a lighter
form of synchronization for other uses.. but not right now.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 12:58:09 -08:00
Wu Fengguang
df4927bf6c generic swap(): sched: remove local swap() macro
Use the new generic implementation.

Signed-off-by: Wu Fengguang <wfg@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:15 -08:00
Eric W. Biederman
61bce0f137 pid: generalize task_active_pid_ns
Currently task_active_pid_ns is not safe to call after a task becomes a
zombie and exit_task_namespaces is called, as nsproxy becomes NULL.  By
reading the pid namespace from the pid of the task we can trivially solve
this problem at the cost of one extra memory read in what should be the
same cacheline as we read the namespace from.

When moving things around I have made task_active_pid_ns out of line
because keeping it in pid_namespace.h would require adding includes of
pid.h and sched.h that I don't think we want.

This change does make task_active_pid_ns unsafe to call during
copy_process until we attach a pid on the task_struct which seems to be a
reasonable trade off.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Bastian Blank <bastian@waldi.eu.org>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Nadia Derbey <Nadia.Derbey@bull.net>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:12 -08:00
Li Zefan
6af866af34 cpuset: remove remaining pointers to cpumask_t
Impact: cleanups, use new cpumask API

Final trivial cleanups: mainly s/cpumask_t/struct cpumask

Note there is a FIXME in generate_sched_domains(). A future patch will
change struct cpumask *doms to struct cpumask *doms[].
(I suppose Rusty will do this.)

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Mike Travis <travis@sgi.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:11 -08:00
Li Zefan
300ed6cbb7 cpuset: convert cpuset->cpus_allowed to cpumask_var_t
Impact: use new cpumask API

This patch mainly does the following things:
- change cs->cpus_allowed from cpumask_t to cpumask_var_t
- call alloc_bootmem_cpumask_var() for top_cpuset in cpuset_init_early()
- call alloc_cpumask_var() for other cpusets
- replace cpus_xxx() to cpumask_xxx()

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Mike Travis <travis@sgi.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:11 -08:00
Li Zefan
645fcc9d2f cpuset: don't allocate trial cpuset on stack
Impact: cleanups, reduce stack usage

This patch prepares for the next patch.  When we convert
cpuset.cpus_allowed to cpumask_var_t, (trialcs = *cs) no longer works.

Another result of this patch is reducing stack usage of trialcs.
sizeof(*cs) can be as large as 148 bytes on x86_64, so it's really not
good to have it on stack.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Mike Travis <travis@sgi.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:11 -08:00
Li Zefan
2341d1b659 cpuset: convert cpuset_attach() to use cpumask_var_t
Impact: reduce stack usage

Allocate a global cpumask_var_t at boot, and use it in cpuset_attach(), so
we won't fail cpuset_attach().

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Mike Travis <travis@sgi.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:11 -08:00
Li Zefan
5771f0a223 cpuset: remove on stack cpumask_t in cpuset_can_attach()
Impact: reduce stack usage

Just use cs->cpus_allowed, and no need to allocate a cpumask_var_t.

Signed-off-by: Li Zefan <lizf@cn.fujistu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Mike Travis <travis@sgi.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:11 -08:00
Li Zefan
5a7625df72 cpuset: remove on stack cpumask_t in cpuset_sprintf_cpulist()
This patchset converts cpuset to use new cpumask API, and thus
remove on stack cpumask_t to reduce stack usage.

Before:
 # cat kernel/cpuset.c include/linux/cpuset.h | grep -c cpumask_t
 21
After:
 # cat kernel/cpuset.c include/linux/cpuset.h | grep -c cpumask_t
 0

This patch:

Impact: reduce stack usage

It's safe to call cpulist_scnprintf inside callback_mutex, and thus we can
just remove the cpumask_t and no need to allocate a cpumask_var_t.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Mike Travis <travis@sgi.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:11 -08:00
Miao Xie
f5813d9427 cpusets: set task's cpu_allowed to cpu_possible_map when attaching it into top cpuset
I found a bug on my dual-cpu box.  I created a sub cpuset in top cpuset
and assign 1 to its cpus.  And then we attach some tasks into this sub
cpuset.  After this, we offline CPU1.  Now, the tasks in this new cpuset
are moved into top cpuset automatically because there is no cpu in sub
cpuset.  Then we online CPU1, we find all the tasks which doesn't belong
to top cpuset originally just run on CPU0.

We fix this bug by setting task's cpu_allowed to cpu_possible_map when
attaching it into top cpuset.  This method needn't modify the current
behavior of cpusets on CPU hotplug, and all of tasks in top cpuset use
cpu_possible_map to initialize their cpu_allowed.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:11 -08:00
Lai Jiangshan
13337714f3 cpuset: rcu_read_lock() to protect task_cs()
task_cs() calls task_subsys_state().

We must use rcu_read_lock() to protect cgroup_subsys_state().

It's correct that top_cpuset is never freed, but cgroup_subsys_state()
accesses css_set, this css_set maybe freed when task_cs() called.

We use use rcu_read_lock() to protect it.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: Paul Menage <menage@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:11 -08:00
Paul Menage
e7c5ec9193 cgroups: add css_tryget()
Add css_tryget(), that obtains a counted reference on a CSS.  It is used
in situations where the caller has a "weak" reference to the CSS, i.e.
one that does not protect the cgroup from removal via a reference count,
but would instead be cleaned up by a destroy() callback.

css_tryget() will return true on success, or false if the cgroup is being
removed.

This is similar to Kamezawa Hiroyuki's patch from a week or two ago, but
with the difference that in the event of css_tryget() racing with a
cgroup_rmdir(), css_tryget() will only return false if the cgroup really
does get removed.

This implementation is done by biasing css->refcnt, so that a refcnt of 1
means "releasable" and 0 means "released or releasing".  In the event of a
race, css_tryget() distinguishes between "released" and "releasing" by
checking for the CSS_REMOVED flag in css->flags.

Signed-off-by: Paul Menage <menage@google.com>
Tested-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:10 -08:00
Paul Menage
999cd8a450 cgroups: add a per-subsystem hierarchy_mutex
These patches introduce new locking/refcount support for cgroups to
reduce the need for subsystems to call cgroup_lock(). This will
ultimately allow the atomicity of cgroup_rmdir() (which was removed
recently) to be restored.

These three patches give:

1/3 - introduce a per-subsystem hierarchy_mutex which a subsystem can
     use to prevent changes to its own cgroup tree

2/3 - use hierarchy_mutex in place of calling cgroup_lock() in the
     memory controller

3/3 - introduce a css_tryget() function similar to the one recently
      proposed by Kamezawa, but avoiding spurious refcount failures in
      the event of a race between a css_tryget() and an unsuccessful
      cgroup_rmdir()

Future patches will likely involve:

- using hierarchy mutex in place of cgroup_lock() in more subsystems
 where appropriate

- restoring the atomicity of cgroup_rmdir() with respect to cgroup_create()

This patch:

Add a hierarchy_mutex to the cgroup_subsys object that protects changes to
the hierarchy observed by that subsystem.  It is taken by the cgroup
subsystem (in addition to cgroup_mutex) for the following operations:

- linking a cgroup into that subsystem's cgroup tree
- unlinking a cgroup from that subsystem's cgroup tree
- moving the subsystem to/from a hierarchy (including across the
  bind() callback)

Thus if the subsystem holds its own hierarchy_mutex, it can safely
traverse its own hierarchy.

Signed-off-by: Paul Menage <menage@google.com>
Tested-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:10 -08:00
Balbir Singh
28dbc4b6a0 memcg: memory cgroup resource counters for hierarchy
Add support for building hierarchies in resource counters.  Cgroups allows
us to build a deep hierarchy, but we currently don't link the resource
counters belonging to the memory controller control groups, in the same
fashion as the corresponding cgroup entries in the cgroup hierarchy.  This
patch provides the infrastructure for resource counters that have the same
hiearchy as their cgroup counter parts.

These set of patches are based on the resource counter hiearchy patches
posted by Pavel Emelianov.

NOTE: Building hiearchies is expensive, deeper hierarchies imply charging
the all the way up to the root.  It is known that hiearchies are
expensive, so the user needs to be careful and aware of the trade-offs
before creating very deep ones.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Paul Menage <menage@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:05 -08:00
Paul Menage
a47295e6bc cgroups: make cgroup_path() RCU-safe
Fix races between /proc/sched_debug by freeing cgroup objects via an RCU
callback.  Thus any cgroup reference obtained from an RCU-safe source will
remain valid during the RCU section.  Since dentries are also RCU-safe,
this allows us to traverse up the tree safely.

Additionally, make cgroup_path() check for a NULL cgrp->dentry to avoid
trying to report a path for a partially-created cgroup.

[lizf@cn.fujitsu.com: call deactive_super() in cgroup_diput()]
Signed-off-by: Paul Menage <menage@google.com>
Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Tested-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:03 -08:00
Gowrishankar M
e7b80bb695 cgroups: skip processes from other namespaces when listing a cgroup
Once tasks are populated from system namespace inside cgroup, container
replaces other namespace task with 0 while listing tasks, inside
container.

Though this is expected behaviour from container end, there is no use of
showing unwanted 0s.

In this patch, we check if a process is in same namespace before loading
into pid array.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Gowrishankar M <gowrishankar.m@in.ibm.com>
Acked-by: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:03 -08:00
Li Zefan
c12f65d439 cgroups: introduce link_css_set() to remove duplicate code
Add a common function link_css_set() to link a css_set to a cgroup.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:03 -08:00
Li Zefan
33a68ac1c1 cgroups: add inactive subsystems to rootnode.subsys_list
Though for an inactive hierarchy, we have subsys->root == &rootnode, but
rootnode's subsys_list is always empty.

This conflicts with the code in find_css_set():

	for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
		...
		if (ss->root->subsys_list.next == &ss->sibling) {
			...
		}
	}
	if (list_empty(&rootnode.subsys_list)) {
		...
	}

The above code assumes rootnode.subsys_list links all inactive
hierarchies.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:03 -08:00
Li Zefan
e5f6a8609b cgroups: make root_list contains active hierarchies only
Don't link rootnode to the root list, so root_list contains active
hierarchies only as the comment indicates.  And rename for_each_root() to
for_each_active_root().

Also remove redundant check in cgroup_kill_sb().

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:03 -08:00
Lai Jiangshan
7534432dcc cgroups: remove rcu_read_lock() in cgroupstats_build()
cgroup_iter_* do not need rcu_read_lock().

In cgroup_enable_task_cg_lists(), do_each_thread() and while_each_thread()
are protected by RCU, it's OK, for write_lock(&css_set_lock) implies
rcu_read_lock() in non-RT kernel.

If we need explicit rcu_read_lock(), we should add rcu_read_lock() in
cgroup_enable_task_cg_lists(), not cgroup_iter_*.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: Paul Menage <menage@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:03 -08:00
Lai Jiangshan
77efecd9e0 cgroups: call find_css_set() safely in cgroup_attach_task()
In cgroup_attach_task(), tsk maybe exit when we call find_css_set().  and
find_css_set() will access to invalid css_set.

This patch increases the count before get_css_set(), and decreases it
after find_css_set().

NOTE:

css_set's refcount is also taskcount, after this patch applied, taskcount
may be off-by-one WHEN cgroup_lock() is not held.  but I reviewed other
code which use taskcount, they are still correct.  No regression found by
reviewing and simply testing.

So I do not use two counters in css_set.  (one counter for taskcount, the
other for refcount.  like struct mm_struct) If this fix cause regression,
we will use two counters in css_set.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:02 -08:00
Lai Jiangshan
104cbd5537 cgroups: use task_lock() for access tsk->cgroups safe in cgroup_clone()
Use task_lock() protect tsk->cgroups and get_css_set(tsk->cgroups).

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: Paul Menage <menage@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:02 -08:00
Lai Jiangshan
b2aa30f7bb cgroups: don't put struct cgroupfs_root protected by RCU
We don't access struct cgroupfs_root in fast path, so we should not put
struct cgroupfs_root protected by RCU

But the comment in struct cgroup_subsys.root confuse us.

struct cgroup_subsys.root is used in these places:

1 find_css_set(): if (ss->root->subsys_list.next == &ss->sibling)
2 rebind_subsystems(): if (ss->root != &rootnode)
                       rcu_assign_pointer(ss->root, root);
                       rcu_assign_pointer(subsys[i]->root, &rootnode);
3 cgroup_has_css_refs(): if (ss->root != cgrp->root)
4 cgroup_init_subsys(): ss->root = &rootnode;
5 proc_cgroupstats_show(): ss->name, ss->root->subsys_bits,
                           ss->root->number_of_cgroups, !ss->disabled);
6 cgroup_clone(): root = subsys->root;
                  if ((root != subsys->root) ||

All these place we have held cgroup_lock() or we don't dereference to
struct cgroupfs_root.  It's means wo don't need RCU when use struct
cgroup_subsys.root, and we should not put struct cgroupfs_root protected
by RCU.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Reviewed-by: Paul Menage <menage@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:02 -08:00
Lai Jiangshan
2019f634ce cgroups: fix cgroup_iter_next() bug
We access res->cgroups without the task_lock(), so res->cgroups may be
changed.  it's unreliable, and "if (l == &res->cgroups->tasks)" may be
false forever.

We don't need add any lock for fixing this bug.  we just access to struct
css_set by struct cg_cgroup_link, not by struct task_struct.

Since we hold css_set_lock, struct cg_cgroup_link is reliable.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Reviewed-by: Paul Menage <menage@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:02 -08:00
Lai Jiangshan
b12b533fa5 cgroups: add lock for child->cgroups in cgroup_post_fork()
When cgroup_post_fork() is called, child is seen by find_task_by_vpid(),
so child->cgroups maybe be changed, It'll incorrect.

child->cgroups<old>'s refcnt is decreased
child->cgroups<new>'s refcnt is increased
but child->cg_list is added to child->cgroups<old>'s list.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Reviewed-by: Paul Menage <menage@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:02 -08:00
Li Zefan
cae7a366f7 ns_cgroup: remove unused spinlock
I happened to find the spinlock in struct ns_cgroup is never used.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:02 -08:00
Li Zefan
75139b8274 cgroups: remove some redundant NULL checks
- In cgroup_clone(), if vfs_mkdir() returns successfully,
  dentry->d_fsdata will be the pointer to the newly created
  cgroup and won't be NULL.

- a cgroup file's dentry->d_fsdata won't be NULL, guaranteed
  by cgroup_add_file().

- When walking through the subsystems of a cgroup_fs (using
  for_each_subsys), cgrp->subsys[ss->subsys_id] won't be NULL,
  guaranteed by cgroup_create().

(Also remove 2 unused variables in cgroup_rmdir().

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:01 -08:00
Robert Richter
d2852b932f Merge branch 'oprofile/ring_buffer' into oprofile/oprofile-for-tip 2009-01-08 14:27:34 +01:00
David Howells
b9456371a7 CRED: Fix commit_creds() on a process that has no mm
Fix commit_creds()'s handling of a process that has no mm (such as one that is
calling or has called daemonize()).  commit_creds() should check to see if
task->mm is not NULL before calling set_dumpable() on it.

Reported-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-01-08 23:13:56 +11:00
Paul Mundt
dd8632a12e NOMMU: Make mmap allocation page trimming behaviour configurable.
NOMMU mmap allocates a piece of memory for an mmap that's rounded up in size to
the nearest power-of-2 number of pages.  Currently it then discards the excess
pages back to the page allocator, making that memory available for use by other
things.  This can, however, cause greater amount of fragmentation.

To counter this, a sysctl is added in order to fine-tune the trimming
behaviour.  The default behaviour remains to trim pages aggressively, while
this can either be disabled completely or set to a higher page-granular
watermark in order to have finer-grained control.

vm region vm_top bits taken from an earlier patch by David Howells.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Mike Frysinger <vapier.adi@gmail.com>
2009-01-08 12:04:47 +00:00
David Howells
8feae13110 NOMMU: Make VMAs per MM as for MMU-mode linux
Make VMAs per mm_struct as for MMU-mode linux.  This solves two problems:

 (1) In SYSV SHM where nattch for a segment does not reflect the number of
     shmat's (and forks) done.

 (2) In mmap() where the VMA's vm_mm is set to point to the parent mm by an
     exec'ing process when VM_EXECUTABLE is specified, regardless of the fact
     that a VMA might be shared and already have its vm_mm assigned to another
     process or a dead process.

A new struct (vm_region) is introduced to track a mapped region and to remember
the circumstances under which it may be shared and the vm_list_struct structure
is discarded as it's no longer required.

This patch makes the following additional changes:

 (1) Regions are now allocated with alloc_pages() rather than kmalloc() and
     with no recourse to __GFP_COMP, so the pages are not composite.  Instead,
     each page has a reference on it held by the region.  Anything else that is
     interested in such a page will have to get a reference on it to retain it.
     When the pages are released due to unmapping, each page is passed to
     put_page() and will be freed when the page usage count reaches zero.

 (2) Excess pages are trimmed after an allocation as the allocation must be
     made as a power-of-2 quantity of pages.

 (3) VMAs are added to the parent MM's R/B tree and mmap lists.  As an MM may
     end up with overlapping VMAs within the tree, the VMA struct address is
     appended to the sort key.

 (4) Non-anonymous VMAs are now added to the backing inode's prio list.

 (5) Holes may be punched in anonymous VMAs with munmap(), releasing parts of
     the backing region.  The VMA and region structs will be split if
     necessary.

 (6) sys_shmdt() only releases one attachment to a SYSV IPC shared memory
     segment instead of all the attachments at that addresss.  Multiple
     shmat()'s return the same address under NOMMU-mode instead of different
     virtual addresses as under MMU-mode.

 (7) Core dumping for ELF-FDPIC requires fewer exceptions for NOMMU-mode.

 (8) /proc/maps is now the global list of mapped regions, and may list bits
     that aren't actually mapped anywhere.

 (9) /proc/meminfo gains a line (tagged "MmapCopy") that indicates the amount
     of RAM currently allocated by mmap to hold mappable regions that can't be
     mapped directly.  These are copies of the backing device or file if not
     anonymous.

These changes make NOMMU mode more similar to MMU mode.  The downside is that
NOMMU mode requires some extra memory to track things over NOMMU without this
patch (VMAs are no longer shared, and there are now region structs).

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Mike Frysinger <vapier.adi@gmail.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
2009-01-08 12:04:47 +00:00
Linus Torvalds
8cfc7f9c00 Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched: fix possible recursive rq->lock
2009-01-07 15:43:58 -08:00
Linus Torvalds
b424e8d3b4 Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6
* 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6: (98 commits)
  PCI PM: Put PM callbacks in the order of execution
  PCI PM: Run default PM callbacks for all devices using new framework
  PCI PM: Register power state of devices during initialization
  PCI PM: Call pci_fixup_device from legacy routines
  PCI PM: Rearrange code in pci-driver.c
  PCI PM: Avoid touching devices behind bridges in unknown state
  PCI PM: Move pci_has_legacy_pm_support
  PCI PM: Power-manage devices without drivers during suspend-resume
  PCI PM: Add suspend counterpart of pci_reenable_device
  PCI PM: Fix poweroff and restore callbacks
  PCI: Use msleep instead of cpu_relax during ASPM link retraining
  PCI: PCIe portdrv: Add kerneldoc comments to remining core funtions
  PCI: PCIe portdrv: Rearrange code so that related things are together
  PCI: PCIe portdrv: Fix suspend and resume of PCI Express port services
  PCI: PCIe portdrv: Add kerneldoc comments to some core functions
  x86/PCI: Do not use interrupt links for devices using MSI-X
  net: sfc: Use pci_clear_master() to disable bus mastering
  PCI: Add pci_clear_master() as opposite of pci_set_master()
  PCI hotplug: remove redundant test in cpq hotplug
  PCI: pciehp: cleanup register and field definitions
  ...
2009-01-07 15:41:01 -08:00
Linus Torvalds
67acd8b4b7 Merge git://git.kernel.org/pub/scm/linux/kernel/git/arjan/linux-2.6-async
* git://git.kernel.org/pub/scm/linux/kernel/git/arjan/linux-2.6-async:
  async: don't do the initcall stuff post boot
  bootchart: improve output based on Dave Jones' feedback
  async: make the final inode deletion an asynchronous event
  fastboot: Make libata initialization even more async
  fastboot: make the libata port scan asynchronous
  fastboot: make scsi probes asynchronous
  async: Asynchronous function calls to speed up kernel boot
2009-01-07 15:35:47 -08:00
Paul E. McKenney
c9d557c19f rcu: fix bug in rcutorture system-shutdown code
This patch fixes an rcutorture bug found by Eric Sesterhenn that
resulted in oopses in response to "rmmod rcutorture".  The problem
was in some new code that attempted to handle the case where a system
is shut down while rcutorture is still running, for example, when
rcutorture is built into the kernel so that it cannot be removed.
The fix causes the rcutorture threads to "park" in an
schedule_timeout_uninterruptible(MAX_SCHEDULE_TIMEOUT) rather than
trying to get them to terminate cleanly.  Concurrent shutdown and
rmmod is illegal.

I believe that this is 2.6.29 material, as it is used in some testing
setups.

For reference, here are the rcutorture operating modes:

CONFIG_RCU_TORTURE_TEST=m

	This is the normal rcutorture build.  Use "modprobe rcutorture"
	(with optional arguments) to start, and "rmmod rcutorture" to
	stop.  If you shut the system down without doing the rmmod, you
	should see console output like:

	rcutorture thread rcu_torture_writer parking due to system shutdown

	One for each rcutorture kthread.

CONFIG_RCU_TORTURE_TEST=y
CONFIG_RCU_TORTURE_TEST_RUNNABLE=n

	Use this if you want rcutorture built in, but don't want the
	test to start running during early boot.  To start the
	torturing:

		echo 1 > /proc/sys/kernel/rcutorture_runnable

	To stop the torturing, s/1/0/

	You will get "parking" console messages as noted above when
	you shut the system down.

CONFIG_RCU_TORTURE_TEST=y
CONFIG_RCU_TORTURE_TEST_RUNNABLE=y

	Same as above, except that the torturing starts during early
	boot.  Only for the stout of heart and strong of stomach.
	The same /proc entry noted above may be used to control the
	test.

Located-by: Eric Sesterhenn <snakebyte@gmx.de>
Tested-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-07 23:36:25 +01:00