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1418 commits

Author SHA1 Message Date
Mike Travis
9f248bde9d x86: remove the static 256k node_to_cpumask_map
* Consolidate node_to_cpumask operations and remove the 256k
    byte node_to_cpumask_map.  This is done by allocating the
    node_to_cpumask_map array after the number of possible nodes
    (nr_node_ids) is known.

  * Debug printouts when CONFIG_DEBUG_PER_CPU_MAPS is active have
    been increased.  It now shows faults when calling node_to_cpumask()
    and node_to_cpumask_ptr().

For inclusion into sched-devel/latest tree.

Based on:
	git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
    +   sched-devel/latest  .../mingo/linux-2.6-sched-devel.git

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-07-08 11:31:24 +02:00
Mike Travis
7891a24e1e x86: restore pda nodenumber field
* Restore the nodenumber field in the x86_64 pda.  This field is slightly
    different than the x86_cpu_to_node_map mainly because it's a static
    indication of which node the cpu is on while the cpu to node map is a
    dyanamic mapping that may get reset if the cpu goes offline.  This also
    simplifies the numa_node_id() macro.

For inclusion into sched-devel/latest tree.

Based on:
	git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
    +   sched-devel/latest  .../mingo/linux-2.6-sched-devel.git

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-07-08 11:31:23 +02:00
Mike Travis
23ca4bba3e x86: cleanup early per cpu variables/accesses v4
* Introduce a new PER_CPU macro called "EARLY_PER_CPU".  This is
    used by some per_cpu variables that are initialized and accessed
    before there are per_cpu areas allocated.

    ["Early" in respect to per_cpu variables is "earlier than the per_cpu
    areas have been setup".]

    This patchset adds these new macros:

	DEFINE_EARLY_PER_CPU(_type, _name, _initvalue)
	EXPORT_EARLY_PER_CPU_SYMBOL(_name)
	DECLARE_EARLY_PER_CPU(_type, _name)

	early_per_cpu_ptr(_name)
	early_per_cpu_map(_name, _idx)
	early_per_cpu(_name, _cpu)

    The DEFINE macro defines the per_cpu variable as well as the early
    map and pointer.  It also initializes the per_cpu variable and map
    elements to "_initvalue".  The early_* macros provide access to
    the initial map (usually setup during system init) and the early
    pointer.  This pointer is initialized to point to the early map
    but is then NULL'ed when the actual per_cpu areas are setup.  After
    that the per_cpu variable is the correct access to the variable.

    The early_per_cpu() macro is not very efficient but does show how to
    access the variable if you have a function that can be called both
    "early" and "late".  It tests the early ptr to be NULL, and if not
    then it's still valid.  Otherwise, the per_cpu variable is used
    instead:

	#define early_per_cpu(_name, _cpu) 			\
		(early_per_cpu_ptr(_name) ?			\
			early_per_cpu_ptr(_name)[_cpu] :	\
			per_cpu(_name, _cpu))

    A better method is to actually check the pointer manually.  In the
    case below, numa_set_node can be called both "early" and "late":

	void __cpuinit numa_set_node(int cpu, int node)
	{
	    int *cpu_to_node_map = early_per_cpu_ptr(x86_cpu_to_node_map);

	    if (cpu_to_node_map)
		    cpu_to_node_map[cpu] = node;
	    else
		    per_cpu(x86_cpu_to_node_map, cpu) = node;
	}

  * Add a flag "arch_provides_topology_pointers" that indicates pointers
    to topology cpumask_t maps are available.  Otherwise, use the function
    returning the cpumask_t value.  This is useful if cpumask_t set size
    is very large to avoid copying data on to/off of the stack.

  * The coverage of CONFIG_DEBUG_PER_CPU_MAPS has been increased while
    the non-debug case has been optimized a bit.

  * Remove an unreferenced compiler warning in drivers/base/topology.c

  * Clean up #ifdef in setup.c

For inclusion into sched-devel/latest tree.

Based on:
	git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
    +   sched-devel/latest  .../mingo/linux-2.6-sched-devel.git

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-07-08 11:31:20 +02:00
Mike Travis
7496b60654 x86: fix remove cpu_pda table patch
Mike Travis wrote:
> Ingo Molnar wrote:
>> * Mike Travis <travis@sgi.com> wrote:
>>
>>> [Ingo - please replace "PATCH 07/11" with this one.]
>>>
>>>     *	Remove 544k bytes from the kernel by removing the boot_cpu_pda
>>> 	array from the data section and allocating it during startup.
>>>
>>> 	Fixed panic in setup_per_cpu_areas when HOTPLUG_CPU not set.
>>>
>>> For inclusion into sched-devel/latest tree.
>> sched-devel.git randconfig testing found another crash with your queue:
>>
>> [    0.111060] Brought up 1 CPUs
>> [    0.111986] Total of 1 processors activated (4022.73 BogoMIPS).
>> [    0.112987] Testing NMI watchdog ... <1>BUG: unable to handle kernel NULL pointer dereference at 0000000000000040
>> [    0.114982] IP: [<ffffffff8180d4a0>] check_nmi_watchdog+0xb0/0x210
>> [    0.114982] PGD 0
>> [    0.114982] Oops: 0000 [1] SMP
>> [    0.114982] CPU 0
>> [............]
>>
>>  http://redhat.com/~mingo/misc/config-Mon_Apr_28_23_25_25_CEST_2008.bad
>>  http://redhat.com/~mingo/misc/log-Mon_Apr_28_23_25_25_CEST_2008.bad
>>
>> 	Ingo
>
> Hi Ingo,
>
> I need a bit more information on your hardware configuration.  Building a
> kernel with the above config file started up fine on both the Intel and AMD
> boxes.
>
> Based on the above output it looks like it might be a UP machine?
...

Ok, I think I found it.  In check_nmi_watchdog():

        for (cpu = 0; cpu < NR_CPUS; cpu++)
                prev_nmi_count[cpu] = cpu_pda(cpu)->__nmi_count;

As I mentioned it works fine on both of my systems so could you try it out?

Thanks!
Mike
--

  * Change function check_nmi_watchdog() to use nr_cpu_ids instead of NR_CPUS.

Based on:
	git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
    +   sched-devel/latest  .../mingo/linux-2.6-sched-devel.git

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-07-08 11:28:47 +02:00
Ingo Molnar
a1716d508a Merge branch 'x86/s2ram-fix' into x86/urgent 2008-07-05 08:42:45 +02:00
Rafael J. Wysocki
64e83b5a91 x86 ACPI: fix resume from suspend to RAM on uniprocessor x86-64
Since the trampoline code is now used for ACPI resume from suspend to RAM,
the trampoline page tables have to be fixed up during boot not only on SMP
systems, but also on UP systems that use the trampoline.

Reference: http://bugzilla.kernel.org/show_bug.cgi?id=10923

Reported-by: Dionisus Torimens <djtm@gmx.net>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: pm list <linux-pm@lists.linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-05 08:42:28 +02:00
H. Peter Anvin
4b4f7280d7 x86 ACPI: normalize segment descriptor register on resume
Some Dell laptops enter resume with apparent garbage in the segment
descriptor registers (almost certainly the result of a botched
transition from protected to real mode.)  The only way to clean that
up is to enter protected mode ourselves and clean out the descriptor
registers.

This fixes resume on Dell XPS M1210 and Dell D620.

Reference: http://bugzilla.kernel.org/show_bug.cgi?id=10927

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: pm list <linux-pm@lists.linux-foundation.org>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Tested-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-05 08:25:40 +02:00
Linus Torvalds
b8a0b6ccf2 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:
  xen: fix address truncation in pte mfn<->pfn conversion
  arch/x86/mm/init_64.c: early_memtest(): fix types
  x86: fix Intel Mac booting with EFI
2008-07-04 10:46:46 -07:00
Hugh Dickins
216705d272 x86: fix Intel Mac booting with EFI
Fedora reports that mem_init()'s zap_low_mappings(), extended to SMP in
61165d7a03 x86: fix app crashes after SMP
resume causes 32-bit Intel Mac machines to reboot very early when
booting with EFI.

The EFI code appears to manage low mappings for itself when needed; but
like many before it, confuses PSE with PAE.  So it has only been mapping
half the space it needed when PSE but not PAE.  This remained unnoticed
until we moved the SMP zap_low_mappings() before
efi_enter_virtual_mode().  Presumably could have been noticed years ago
if anyone ran a UP kernel on such machines?

Reported-by: Peter Jones <pjones@redhat.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Peter Jones <pjones@redhat.com>
Cc: Glauber Costa <gcosta@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Tested-by: Peter Jones <pjones@redhat.com>
2008-07-03 08:19:18 +02:00
Linus Torvalds
bbad5d4750 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:
  ptrace GET/SET FPXREGS broken
  x86: fix cpu hotplug crash
  x86: section/warning fixes
  x86: shift bits the right way in native_read_tscp
2008-06-30 08:56:57 -07:00
TAKADA Yoshihito
11dbc963a8 ptrace GET/SET FPXREGS broken
When I update kernel 2.6.25 from 2.6.24, gdb does not work.
On 2.6.25, ptrace(PTRACE_GETFPXREGS, ...) returns ENODEV.

But 2.6.24 kernel's ptrace() returns EIO.
It is issue of compatibility.

I attached test program as pt.c and patch for fix it.

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <signal.h>
#include <errno.h>
#include <sys/ptrace.h>
#include <sys/types.h>

struct user_fxsr_struct {
	unsigned short	cwd;
	unsigned short	swd;
	unsigned short	twd;
	unsigned short	fop;
	long	fip;
	long	fcs;
	long	foo;
	long	fos;
	long	mxcsr;
	long	reserved;
	long	st_space[32];	/* 8*16 bytes for each FP-reg = 128 bytes */
	long	xmm_space[32];	/* 8*16 bytes for each XMM-reg = 128 bytes */
	long	padding[56];
};

int main(void)
{
  pid_t pid;

  pid = fork();

  switch(pid){
  case -1:/*  error */
    break;
  case 0:/*  child */
    child();
    break;
  default:
    parent(pid);
    break;
  }
  return 0;
}

int child(void)
{
  ptrace(PTRACE_TRACEME);
  kill(getpid(), SIGSTOP);
  sleep(10);
  return 0;
}
int parent(pid_t pid)
{
  int ret;
  struct user_fxsr_struct fpxregs;

  ret = ptrace(PTRACE_GETFPXREGS, pid, 0, &fpxregs);
  if(ret < 0){
    printf("%d: %s.\n", errno, strerror(errno));
  }
  kill(pid, SIGCONT);
  wait(pid);
  return 0;
}

/* in the kerel, at kernel/i387.c get_fpxregs() */

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-30 14:35:18 +02:00
Zhang, Yanmin
fcb43042ef x86: fix cpu hotplug crash
Vegard Nossum reported crashes during cpu hotplug tests:

  http://marc.info/?l=linux-kernel&m=121413950227884&w=4

In function _cpu_up, the panic happens when calling
__raw_notifier_call_chain at the second time. Kernel doesn't panic when
calling it at the first time. If just say because of nr_cpu_ids, that's
not right.

By checking the source code, I found that function do_boot_cpu is the culprit.
Consider below call chain:
 _cpu_up=>__cpu_up=>smp_ops.cpu_up=>native_cpu_up=>do_boot_cpu.

So do_boot_cpu is called in the end. In do_boot_cpu, if
boot_error==true, cpu_clear(cpu, cpu_possible_map) is executed. So later
on, when _cpu_up calls __raw_notifier_call_chain at the second time to
report CPU_UP_CANCELED, because this cpu is already cleared from
cpu_possible_map, get_cpu_sysdev returns NULL.

Many resources are related to cpu_possible_map, so it's better not to
change it.

Below patch against 2.6.26-rc7 fixes it by removing the bit clearing in
cpu_possible_map.

Signed-off-by: Zhang Yanmin <yanmin_zhang@linux.intel.com>
Tested-by: Vegard Nossum <vegard.nossum@gmail.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-30 13:15:43 +02:00
Gerd Hoffmann
f6e16d5ad4 x86: KVM guest: Use the paravirt clocksource structs and functions
This patch updates the kvm host code to use the pvclock structs
and functions, thereby making it compatible with Xen.

The patch also fixes an initialization bug: on SMP systems the
per-cpu has two different locations early at boot and after CPU
bringup.  kvmclock must take that in account when registering the
physical address within the host.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-06-24 21:02:33 +03:00
Gerd Hoffmann
7af192c954 x86: Add structs and functions for paravirt clocksource
This patch adds structs for the paravirt clocksource ABI
used by both xen and kvm (pvclock-abi.h).

It also adds some helper functions to read system time and
wall clock time from a paravirtual clocksource (pvclock.[ch]).
They are based on the xen code.  They are enabled using
CONFIG_PARAVIRT_CLOCK.

Subsequent patches of this series will put the code in use.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-06-24 21:02:31 +03:00
Jordan Crouse
ffe6e1da86 x86, geode: add a VSA2 ID for General Software
General Software writes their own VSA2 module for their version
of the Geode BIOS, which returns a different ID then the standard
VSA2.  This was causing the framebuffer driver to break for most
GSW boards.

Signed-off-by: Jordan Crouse <jordan.crouse@amd.com>
Cc: tglx@linutronix.de
Cc: linux-geode@lists.infradead.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-19 14:19:03 +02:00
Bernhard Walle
d3942cff62 x86: use BOOTMEM_EXCLUSIVE on 32-bit
This patch uses the BOOTMEM_EXCLUSIVE for crashkernel reservation also for
i386 and prints a error message on failure.

The patch is still for 2.6.26 since it is only bug fixing. The unification
of reserve_crashkernel() between i386 and x86_64 should be done for 2.6.27.

Signed-off-by: Bernhard Walle <bwalle@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: <stable@kernel.org>
2008-06-19 10:08:48 +02:00
Mikael Pettersson
df17b1d990 x86, 32-bit: fix boot failure on TSC-less processors
Booting 2.6.26-rc6 on my 486 DX/4 fails with a "BUG: Int 6"
(invalid opcode) and a kernel halt immediately after the
kernel has been uncompressed. The BUG shows EIP pointing
to an rdtsc instruction in native_read_tsc(), invoked from
native_sched_clock().

(This error occurs so early that not even the serial console
can capture it.)

A bisection showed that this bug first occurs in 2.6.26-rc3-git7,
via commit 9ccc906c97:

>x86: distangle user disabled TSC from unstable
>
>tsc_enabled is set to 0 from the command line switch "notsc" and from
>the mark_tsc_unstable code. Seperate those functionalities and replace
>tsc_enable with tsc_disable. This makes also the native_sched_clock()
>decision when to use TSC understandable.
>
>Preparatory patch to solve the sched_clock() issue on 32 bit.
>
>Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

The core reason for this bug is that native_sched_clock() gets
called before tsc_init().

Before the commit above, tsc_32.c used a "tsc_enabled" variable
which defaulted to 0 == disabled, and which only got enabled late
in tsc_init(). Thus early calls to native_sched_clock() would skip
the TSC and use jiffies instead.

After the commit above, tsc_32.c uses a "tsc_disabled" variable
which defaults to 0, meaning that the TSC is Ok to use. Early calls
to native_sched_clock() now erroneously try to use the TSC on
!cpu_has_tsc processors, leading to invalid opcode exceptions.

My proposed fix is to initialise tsc_disabled to a "soft disabled"
state distinct from the hard disabled state set up by the "notsc"
kernel option. This fixes the native_sched_clock() problem. It also
allows tsc_init() to be simplified: instead of setting tsc_disabled = 1
on every error return, we just set tsc_disabled = 0 once when all
checks have succeeded.

I've verified that this lets my 486 boot again. I've also verified
that a Core2 machine still uses the TSC as clocksource after the patch.

Signed-off-by: Mikael Pettersson <mikpe@it.uu.se>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-19 10:08:47 +02:00
Suresh Siddha
75118a82e2 x86: fix NULL pointer deref in __switch_to
Patrick McHardy reported a crash:

> > I get this oops once a day, its apparently triggered by something
> > run by cron, but the process is a different one each time.
> >
> > Kernel is -git from yesterday shortly before the -rc6 release
> > (last commit is the usb-2.6 merge, the x86 patches are missing),
> > .config is attached.
> >
> > I'll retry with current -git, but the patches that have gone in
> > since I last updated don't look related.
> >
> > [62060.043009] BUG: unable to handle kernel NULL pointer dereference at
> > 000001ff
> > [62060.043009] IP: [<c0102a9b>] __switch_to+0x2f/0x118
> > [62060.043009] *pde = 00000000
> > [62060.043009] Oops: 0002 [#1] PREEMPT

Vegard Nossum analyzed it:

> This decodes to
>
>    0:   0f ae 00                fxsave (%eax)
>
> so it's related to the floating-point context. This is the exact
> location of the crash:
>
> $ addr2line -e arch/x86/kernel/process_32.o -i ab0
> include/asm/i387.h:232
> include/asm/i387.h:262
> arch/x86/kernel/process_32.c:595
>
> ...so it looks like prev_task->thread.xstate->fxsave has become NULL.
> Or maybe it never had any other value.

Somehow (as described below) TS_USEDFPU is set but the fpu is not
allocated or freed.

Another possible FPU pre-emption issue with the sleazy FPU optimization
which was benign before but not so anymore, with the dynamic FPU allocation
patch.

New task is getting exec'd and it is prempted at the below point.

flush_thread() {
	...
	/*
	* Forget coprocessor state..
	*/
	clear_fpu(tsk);
		<----- Preemption point
	clear_used_math();
	...
}

Now when it context switches in again, as the used_math() is still set
and fpu_counter can be > 5, we will do a math_state_restore() which sets
the task's TS_USEDFPU. After it continues from the above preemption point
it does clear_used_math() and much later free_thread_xstate().

Now, at the next context switch, it is quite possible that xstate is
null, used_math() is not set and TS_USEDFPU is still set. This will
trigger unlazy_fpu() causing kernel oops.

Fix this  by clearing tsk's fpu_counter before clearing task's fpu.

Reported-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-19 10:08:45 +02:00
Linus Torvalds
0269c5c6d9 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
  PCI: fixup write combine comment in pci_mmap_resource
  x86: PAT export resource_wc in pci sysfs
  x86, pci-dma.c: don't always add __GFP_NORETRY to gfp
  suspend-vs-iommu: prevent suspend if we could not resume
  x86: pci-dma.c: use __GFP_NO_OOM instead of __GFP_NORETRY
  pci, x86: add workaround for bug in ASUS A7V600 BIOS (rev 1005)
  PCI: use dev_to_node in pci_call_probe
  PCI: Correct last two HP entries in the bfsort whitelist
2008-06-14 13:32:56 -07:00
Stas Sergeev
1da2e3d679 provide rtc_cmos platform device
Recently (around 2.6.25) I've noticed that RTC no longer works for me.  It
turned out this is because I use pnpacpi=off kernel option to work around
the parport_pc bugs.  I always did so, but RTC used to work fine in the
past, and now it have regressed.

The patch fixes the problem by creating the platform device for the RTC
when PNP is disabled.  This may also help running the PNP-enabled kernel
on an older PCs.

Signed-off-by: Stas Sergeev <stsp@aknet.ru>
Cc: David Brownell <david-b@pacbell.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Adam Belay <ambx1@neo.rr.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-12 18:05:42 -07:00
Jesse Barnes
883eed1b3e Merge branch 'pci-for-jesse' of git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-tip into for-linus 2008-06-12 13:51:05 -07:00
Vegard Nossum
4461145ef1 x86, lockdep: fix "WARNING: at kernel/lockdep.c:2658 check_flags+0x4c/0x128()"
Alessandro Suardi reported:
> Recently upgraded my FC6 desktop to Fedora 9; with the
>  latest nautilus RPM updates my VNC session went nuts
>  with nautilus pegging the CPU for everything that breathed.
>
> I now reverted to an earlier nautilus package, but during
>  the peak CPU period my kernel spat this:
>
> [314185.623294] ------------[ cut here ]------------
> [314185.623414] WARNING: at kernel/lockdep.c:2658 check_flags+0x4c/0x128()
> [314185.623514] Modules linked in: iptable_filter ip_tables x_tables
> sunrpc ipv6 fuse snd_via82xx snd_ac97_codec ac97_bus snd_mpu401_uart
> snd_rawmidi via686a hwmon parport_pc sg parport uhci_hcd ehci_hcd
> [314185.623924] Pid: 12314, comm: nautilus Not tainted 2.6.26-rc5-git2 #4
> [314185.624021]  [<c0115b95>] warn_on_slowpath+0x41/0x7b
> [314185.624021]  [<c010de70>] ? do_page_fault+0x2c1/0x5fd
> [314185.624021]  [<c0128396>] ? up_read+0x16/0x28
> [314185.624021]  [<c010de70>] ? do_page_fault+0x2c1/0x5fd
> [314185.624021]  [<c012fa33>] ? __lock_acquire+0xbb4/0xbc3
> [314185.624021]  [<c012d0a0>] check_flags+0x4c/0x128
> [314185.624021]  [<c012fa73>] lock_acquire+0x31/0x7d
> [314185.624021]  [<c0128cf6>] __atomic_notifier_call_chain+0x30/0x80
> [314185.624021]  [<c0128cc6>] ? __atomic_notifier_call_chain+0x0/0x80
> [314185.624021]  [<c0128d52>] atomic_notifier_call_chain+0xc/0xe
> [314185.624021]  [<c0128d81>] notify_die+0x2d/0x2f
> [314185.624021]  [<c01043b0>] do_int3+0x1f/0x4d
> [314185.624021]  [<c02f2d3b>] int3+0x27/0x2c
> [314185.624021]  =======================
> [314185.624021] ---[ end trace 1923f65a2d7bb246 ]---
> [314185.624021] possible reason: unannotated irqs-off.
> [314185.624021] irq event stamp: 488879
> [314185.624021] hardirqs last  enabled at (488879): [<c0102d67>]
> restore_nocheck+0x12/0x15
> [314185.624021] hardirqs last disabled at (488878): [<c0102dca>]
> work_resched+0x19/0x30
> [314185.624021] softirqs last  enabled at (488876): [<c011a1ba>]
> __do_softirq+0xa6/0xac
> [314185.624021] softirqs last disabled at (488865): [<c010476e>]
> do_softirq+0x57/0xa6
>
> I didn't seem to find it with some googling, so here it is.
>
> I was incidentally ltracing that process to try and find out
>  what was gulping down that much CPU (sorry, no idea
>  whether ltrace and the WARNING happened at the same
>  time or which came first) and:

Yeah, this is extremely likely to be the source of the warning.

The warning should be harmless, however.

> Box is my trusty noname K7-800, 512MB RAM; if there's
>  anything else useful I might be able to provide, just ask.

It would be interesting to see where the int3 comes from.  Too bad,
lockdep doesn't provide the register dump. The stacktrace also doesn't
go further than the int3(), I wonder if this int3 came from userspace?
The ltrace readme says "software breakpoints, like gdb", so I guess
this is the case. Yep, seems like it.

This looks relevant:

| commit fb1dac909d
| Author: Peter Zijlstra <a.p.zijlstra@chello.nl>
| Date:   Wed Jan 16 09:51:59 2008 +0100
|
|     lockdep: more hardirq annotations for notify_die()

I'm attaching a similarly-looking patch for this case (DO_VM86_ERROR),
though I suspect it might be missing for the other cases
(DO_ERROR/DO_ERROR_INFO) as well.

Reported-by: Alessandro Suardi <alessandro.suardi@gmail.com>
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-12 21:27:19 +02:00
Peter Zijlstra
e32e58a96d x86: fix lockdep warning during suspend-to-ram
Andrew Morton wrote:

> I've been seeing the below for a long time during suspend-to-ram on the Vaio.
>
>
> PM: Syncing filesystems ... done.
> PM: Preparing system for mem sleep
> Freezing user space processes ... <4>------------[ cut here ]------------
> WARNING: at kernel/lockdep.c:2658 check_flags+0x4c/0x127()
> Modules linked in: i915 drm ipw2200 sonypi ipv6 autofs4 hidp l2cap bluetooth sunrpc nf_conntrack_netbios_ns ipt_REJECT nf_conntrack_ipv4 xt_state nf_conntrack xt_tcpudp iptable_filter ip_tables x_tables acpi_cpufreq nvram ohci1394 ieee1394 ehci_hcd uhci_hcd sg joydev snd_hda_intel snd_seq_dummy sr_mod snd_seq_oss cdrom snd_seq_midi_event snd_seq snd_seq_device snd_pcm_oss snd_mixer_oss ieee80211 pcspkr ieee80211_crypt snd_pcm i2c_i801 snd_timer i2c_core ide_pci_generic piix snd soundcore snd_page_alloc button ext3 jbd ide_disk ide_core [last unloaded: ipw2200]
> Pid: 3250, comm: zsh Not tainted 2.6.26-rc5 #1
>  [<c011c5f5>] warn_on_slowpath+0x41/0x6d
>  [<c01080e6>] ? native_sched_clock+0x82/0x96
>  [<c013789c>] ? mark_held_locks+0x41/0x5c
>  [<c0315688>] ? _spin_unlock_irqrestore+0x36/0x58
>  [<c0137a29>] ? trace_hardirqs_on+0xe6/0x10d
>  [<c0138637>] ? __lock_acquire+0xae3/0xb2b
>  [<c0313413>] ? schedule+0x39b/0x3b4
>  [<c0135596>] check_flags+0x4c/0x127
>  [<c01386b9>] lock_acquire+0x3a/0x86
>  [<c0315075>] _spin_lock+0x26/0x53
>  [<c0140660>] ? refrigerator+0x13/0xc3
>  [<c0140660>] refrigerator+0x13/0xc3
>  [<c012684a>] get_signal_to_deliver+0x3c/0x31e
>  [<c0102fe7>] do_notify_resume+0x91/0x6ee
>  [<c01359fd>] ? lock_release_holdtime+0x50/0x56
>  [<c0315688>] ? _spin_unlock_irqrestore+0x36/0x58
>  [<c0235d24>] ? read_chan+0x0/0x58c
>  [<c0137a29>] ? trace_hardirqs_on+0xe6/0x10d
>  [<c0315694>] ? _spin_unlock_irqrestore+0x42/0x58
>  [<c0230afa>] ? tty_ldisc_deref+0x5c/0x63
>  [<c0233104>] ? tty_read+0x66/0x98
>  [<c014b3f0>] ? audit_syscall_exit+0x2aa/0x2c5
>  [<c0109430>] ? do_syscall_trace+0x6b/0x16f
>  [<c0103a9c>] work_notifysig+0x13/0x1b
>  =======================
> ---[ end trace 25b49fe59a25afa5 ]---
> possible reason: unannotated irqs-off.
> irq event stamp: 58919
> hardirqs last  enabled at (58919): [<c0103afd>] syscall_exit_work+0x11/0x26

Joy - I so love entry.S

Best I can make of it:

syscall_exit_work
  resume_userspace
    DISABLE_INTERRUPTS
    (no TRACE_IRQS_OFF)
      work_pending
        work_notifysig
          do_notify_resume()
            do_signal()
              get_signal_to_deliver()
                try_to_freeze()
                  refrigerator()
                    task_lock() -> check_flags() -> BANG

The normal path is:

syscall_exit_work
  resume_userspace
    DISABLE_INTERRUPTS
    restore_all
      TRACE_IRQS_IRET
      iret

No idea why that would not warn..

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-12 21:27:09 +02:00
Ingo Molnar
0b6a39f7eb Revert "x86: fix ioapic bug again"
This reverts commit 6e908947b4.

Németh Márton reported:

| there is a problem in 2.6.26-rc3 which was not there in case of
| 2.6.25: the CPU wakes up ~90,000 times per sec instead of ~60 per sec.
|
| I also "git bisected" the problem, the result is:
|
| 6e908947b4 is first bad commit
| commit 6e908947b4
| Author: Ingo Molnar <mingo@elte.hu>
| Date:   Fri Mar 21 14:32:36 2008 +0100
|
|     x86: fix ioapic bug again

the original problem is fixed by Maciej W. Rozycki in the tip/x86/apic
branch (confirmed by Márton), but those changes are too intrusive for
v2.6.26 so we'll go for the less intrusive (repeated) revert now.

Reported-and-bisected-by: Németh Márton <nm127@freemail.hu>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-12 21:26:28 +02:00
Joe Korty
86b2b70e15 x86: fix asm warning in head_32.S
On Mon, May 19, 2008 at 04:10:02PM -0700, Linus Torvalds wrote:
> It also causes these warnings on 32-bit PAE:
>
> 	  AS      arch/x86/kernel/head_32.o
> 	arch/x86/kernel/head_32.S: Assembler messages:
> 	arch/x86/kernel/head_32.S:225: Warning: left operand is a bignum; integer 0 assumed
> 	arch/x86/kernel/head_32.S:609: Warning: left operand is a bignum; integer 0 assumed
>
> and I do not see why (the end result seems to be identical).

Fix head_32.S gcc bignum warnings when CONFIG_PAE=y.

    arch/x86/kernel/head_32.S: Assembler messages:
    arch/x86/kernel/head_32.S:225: Warning: left operand is a bignum; integer 0 assumed
    arch/x86/kernel/head_32.S:609: Warning: left operand is a bignum; integer 0 assumed

The assembler was stumbling over the 64-bit constant 0x100000000 in the
KPMDS #define.

Testing: a cmp(1) on head_32.o before and after shows the binary is unchanged.

Signed-off-by: Joe Korty <joe.korty@ccur.com
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Theodore Tso <tytso@mit.edu>
Cc: Gabriel C <nix.or.die@googlemail.com>
Cc: Keith Packard <keithp@keithp.com>
Cc: "Pallipadi Venkatesh" <venkatesh.pallipadi@intel.com>
Cc: Eric Anholt <eric@anholt.net>
Cc: "Siddha Suresh B" <suresh.b.siddha@intel.com>
Cc: bugme-daemon@bugzilla.kernel.org
Cc: airlied@linux.ie
Cc: "Barnes Jesse" <jesse.barnes@intel.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-12 21:26:12 +02:00
Ingo Molnar
3703f39965 geode: fix modular build
-tip testing found this build bug:

 MODPOST 331 modules
 ERROR: "geode_mfgpt_toggle_event" [drivers/watchdog/geodewdt.ko] undefined!
 ERROR: "geode_mfgpt_alloc_timer" [drivers/watchdog/geodewdt.ko] undefined!
 make[1]: *** [__modpost] Error 1
 make: *** [modules] Error 2

with this config:

  http://redhat.com/~mingo/misc/config-Wed_Jun__4_18_01_59_CEST_2008.bad

export those symbols.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-12 21:25:51 +02:00
Miquel van Smoorenburg
b7f09ae583 x86, pci-dma.c: don't always add __GFP_NORETRY to gfp
Currently arch/x86/kernel/pci-dma.c always adds __GFP_NORETRY
to the allocation flags, because it wants to be reasonably
sure not to deadlock when calling alloc_pages().

But really that should only be done in two cases:
- when allocating memory in the lower 16 MB DMA zone.
  If there's no free memory there, waiting or OOM killing is of no use
- when optimistically trying an allocation in the DMA32 zone
  when dma_mask < DMA_32BIT_MASK hoping that the allocation
  happens to fall within the limits of the dma_mask

Also blindly adding __GFP_NORETRY to the the gfp variable might
not be a good idea since we then also use it when calling
dma_ops->alloc_coherent(). Clearing it might also not be a
good idea, dma_alloc_coherent()'s caller might have set it
on purpose. The gfp variable should not be clobbered.

[ mingo@elte.hu: converted to delta patch ontop of previous version. ]

Signed-off-by: Miquel van Smoorenburg <miquels@cistron.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-10 12:22:18 +02:00
Suresh Siddha
870568b390 x86, fpu: fix CONFIG_PREEMPT=y corruption of application's FPU stack
Jürgen Mell reported an FPU state corruption bug under CONFIG_PREEMPT,
and bisected it to commit v2.6.19-1363-gacc2076, "i386: add sleazy FPU
optimization".

Add tsk_used_math() checks to prevent calling math_state_restore()
which can sleep in the case of !tsk_used_math(). This prevents
making a blocking call in __switch_to().

Apparently "fpu_counter > 5" check is not enough, as in some signal handling
and fork/exec scenarios, fpu_counter > 5 and !tsk_used_math() is possible.

It's a side effect though. This is the failing scenario:

process 'A' in save_i387_ia32() just after clear_used_math()

Got an interrupt and pre-empted out.

At the next context switch to process 'A' again, kernel tries to restore
the math state proactively and sees a fpu_counter > 0 and !tsk_used_math()

This results in init_fpu() during the __switch_to()'s math_state_restore()

And resulting in fpu corruption which will be saved/restored
(save_i387_fxsave and restore_i387_fxsave) during the remaining
part of the signal handling after the context switch.

Bisected-by: Jürgen Mell <j.mell@t-online.de>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Tested-by: Jürgen Mell <j.mell@t-online.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@kernel.org
2008-06-04 16:21:24 +02:00
Pavel Machek
cd76374e9d suspend-vs-iommu: prevent suspend if we could not resume
iommu/gart support misses suspend/resume code, which can do bad stuff,
including memory corruption on resume.  Prevent system suspend in case we
would be unable to resume.

Signed-off-by: Pavel Machek <pavel@suse.cz>
Tested-by: Patrick <ragamuffin@datacomm.ch>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-04 13:11:47 +02:00
Suresh Siddha
e8a496ac8c x86: fix broken math-emu with lazy allocation of fpu area
Fix the math emulation that got broken with the recent lazy allocation of FPU
area. init_fpu() need to be added for the math-emulation path aswell
for the FPU area allocation.

math emulation enabled kernel booted fine with this, in the presence
of "no387 nofxsr" boot param.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: hpa@zytor.com
Cc: mingo@elte.hu
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-06-04 13:11:46 +02:00
Ingo Molnar
deef325086 x86: disable preemption in native_smp_prepare_cpus
Priit Laes reported the following warning:

Call Trace:
 [<ffffffff8022f1e1>] warn_on_slowpath+0x51/0x63
 [<ffffffff80282e48>] sys_ioctl+0x2d/0x5d
 [<ffffffff805185ff>] _spin_lock+0xe/0x24
 [<ffffffff80227459>] task_rq_lock+0x3d/0x73
 [<ffffffff805133c3>] set_cpu_sibling_map+0x336/0x350
 [<ffffffff8021c1b8>] read_apic_id+0x30/0x62
 [<ffffffff806d921d>] verify_local_APIC+0x90/0x138
 [<ffffffff806d84b5>] native_smp_prepare_cpus+0x1f9/0x305
 [<ffffffff806ce7b1>] kernel_init+0x59/0x2d9
 [<ffffffff80518a26>] _spin_unlock_irq+0x11/0x2b
 [<ffffffff8020bf48>] child_rip+0xa/0x12
 [<ffffffff806ce758>] kernel_init+0x0/0x2d9
 [<ffffffff8020bf3e>] child_rip+0x0/0x12

fix this by generally disabling preemption in native_smp_prepare_cpus().

Reported-and-bisected-by: Priit Laes <plaes@plaes.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-06-04 13:11:46 +02:00
Yinghai Lu
fb3bbd6a66 x86: fix APIC warning on 32bit v2
for http://bugzilla.kernel.org/show_bug.cgi?id=10613

BIOS bug, APIC version is 0 for CPU#0! fixing up to 0x10. (tell your hw vendor)

v2: fix 64 bit compilation

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Gabriel C <nix.or.die@googlemail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-06-04 13:11:46 +02:00
Pavel Machek
f529626a86 suspend-vs-iommu: prevent suspend if we could not resume
iommu/gart support misses suspend/resume code, which can do bad stuff,
including memory corruption on resume.  Prevent system suspend in case we
would be unable to resume.

Signed-off-by: Pavel Machek <pavel@suse.cz>
Tested-by: Patrick <ragamuffin@datacomm.ch>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-02 13:02:48 +02:00
Miquel van Smoorenburg
db9f600b96 x86: pci-dma.c: use __GFP_NO_OOM instead of __GFP_NORETRY
On Wed, 2008-05-28 at 04:47 +0200, Andi Kleen wrote:
> > So...  why not just remove the setting of __GFP_NORETRY?  Why is it
> > wrong to oom-kill things in this case?
>
> When the 16MB zone overflows (which can be common in some workloads)
> calling the OOM killer is pretty useless because it has barely any
> real user data [only exception would be the "only 16MB" case Alan
> mentioned]. Killing random processes in this case is bad.
>
> I think for 16MB __GFP_NORETRY is ok because there should be
> nothing freeable in there so looping is useless. Only exception would be the
> "only 16MB total" case again but I'm not sure 2.6 supports that at all
> on x86.
>
> On the other hand d_a_c() does more allocations than just 16MB, especially
> on 64bit and the other zones need different strategies.

Okay, so how about this then ?

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-02 12:14:58 +02:00
Linus Torvalds
eb90d81d03 Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-tip:
  x86: prevent PGE flush from interruption/preemption
  x86: use explicit copy in vdso_gettimeofday()
  namespacecheck: automated fixes
  x86/xen: fix arbitrary_virt_to_machine()
  x86: don't read maxlvt before checking if APIC is mapped
  x86: disable TSC for sched_clock() when calibration failed
  x86: distangle user disabled TSC from unstable
  x86: fix setup of cyc2ns in tsc_64.c
2008-05-24 10:20:00 -07:00
Linus Torvalds
e6b027a398 Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq:
  [CPUFREQ] clarify license of freq_table.c
  [CPUFREQ] Remove documentation of removed ondemand tunable.
  [CPUFREQ] Crusoe: longrun cpufreq module reports false min freq
  [CPUFREQ] powernow-k8: improve error messages
2008-05-23 09:24:52 -07:00
Ingo Molnar
2ddfd20e7c namespacecheck: automated fixes
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-05-23 14:08:06 +02:00
Chuck Ebbert
2584a82dee x86: don't read maxlvt before checking if APIC is mapped
A check for unmapped apic was added before reading maxlvt but the early
read of maxlvt wasn't removed.

Signed-off-by: Chuck Ebbert <cebbert@redhat.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@kernel.org
2008-05-23 14:08:06 +02:00
Thomas Gleixner
74dc51a3de x86: disable TSC for sched_clock() when calibration failed
When the TSC calibration fails then TSC is still used in
sched_clock(). Disable it completely in that case.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@kernel.org
2008-05-23 14:08:06 +02:00
Thomas Gleixner
9ccc906c97 x86: distangle user disabled TSC from unstable
tsc_enabled is set to 0 from the command line switch "notsc" and from
the mark_tsc_unstable code. Seperate those functionalities and replace
tsc_enable with tsc_disable. This makes also the native_sched_clock()
decision when to use TSC understandable.

Preparatory patch to solve the sched_clock() issue on 32 bit.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-23 14:08:06 +02:00
Thomas Gleixner
b6db80ee13 x86: fix setup of cyc2ns in tsc_64.c
When the TSC is calibrated against the PIT due to the nonavailability
of PMTIMER/HPET or due to SMI interference then the setup of the per
CPU cyc2ns variables is skipped. This is unlikely to happen but it
would definitely render sched_clock() unusable.

This was introduced with commit 53d517cdba

    x86: scale cyc_2_nsec according to CPU frequency

Update the per CPU cyc2ns variables in all exit pathes of tsc_calibrate.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@kernel.org
2008-05-23 14:08:06 +02:00
Linus Torvalds
e23a5f6687 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
  [PATCH] return to old errno choice in mkdir() et.al.
  [Patch] fs/binfmt_elf.c: fix wrong return values
  [PATCH] get rid of leak in compat_execve()
  [Patch] fs/binfmt_elf.c: fix a wrong free
  [PATCH] avoid multiplication overflows and signedness issues for max_fds
  [PATCH] dup_fd() part 4 - race fix
  [PATCH] dup_fd() - part 3
  [PATCH] dup_fd() part 2
  [PATCH] dup_fd() fixes, part 1
  [PATCH] take init_files to fs/file.c
2008-05-19 16:37:45 -07:00
maximilian attems
667ad4f701 [CPUFREQ] Crusoe: longrun cpufreq module reports false min freq
The longrun cpufreq module reports a false minimum frequency 3MHz on
300-600MHz Crusoe processor.  This may be due to a calculation bug
in the module.

Original patch from Kaz Sasayama <kazssym@hypercore.co.jp>
submitted as http://bugs.debian.org/468149 patch ported to x86

Cc: Kaz Sasayama <kazssym@hypercore.co.jp>
Signed-off-by: maximilian attems <max@stro.at>
Signed-off-by: Dave Jones <davej@redhat.com>
2008-05-19 18:17:28 -04:00
Mark Langsdorf
eba9fe93a2 [CPUFREQ] powernow-k8: improve error messages
The most common error with powernow-k8 is an ACPI _PSS error
caused either by failure to load the ACPI processor module
or a bad parse of the _PSS object.  Make the error message
returned to the user in these situations more straightforward
and easier to understand.

-Mark Langsdorf
Operating System Research Center
AMD

Signed-off-by: Mark Langsdorf <mark.langsdorf@amd.com>
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Signed-off-by: Dave Jones <davej@redhat.com>
2008-05-19 18:17:27 -04:00
Thomas Gleixner
e9623b3559 x86: disable mwait for AMD family 10H/11H CPUs
The previous revert of 0c07ee38c9 left
out the mwait disable condition for AMD family 10H/11H CPUs.

Andreas Herrman said:

It depends on the CPU. For AMD CPUs that support MWAIT this is wrong.
Family 0x10 and 0x11 CPUs will enter C1 on HLT. Powersavings then
depend on a clock divisor and current Pstate of the core.

If all cores of a processor are in halt state (C1) the processor can
enter the C1E (C1 enhanced) state. If mwait is used this will never
happen.

Thus HLT saves more power than MWAIT here.

It might be best to switch off the mwait flag for these AMD CPU
families like it was introduced with commit
f039b75471 (x86: Don't use MWAIT on AMD
Family 10)

Re-add the AMD families 10H/11H check and disable the mwait usage for
those.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-17 22:57:20 +02:00
Ingo Molnar
a738d897b7 x86: remove mwait capability C-state check
Vegard Nossum reports:

| powertop shows between 200-400 wakeups/second with the description
| "<kernel IPI>: Rescheduling interrupts" when all processors have load (e.g.
| I need to run two busy-loops on my 2-CPU system for this to show up).
|
| The bisect resulted in this commit:
|
| commit 0c07ee38c9
| Date:   Wed Jan 30 13:33:16 2008 +0100
|
|     x86: use the correct cpuid method to detect MWAIT support for C states

remove the functional effects of this patch and make mwait unconditional.

A future patch will turn off mwait on specific CPUs where that causes
power to be wasted.

Bisected-by: Vegard Nossum <vegard.nossum@gmail.com>
Tested-by: Vegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-05-17 22:57:20 +02:00
Al Viro
f52111b154 [PATCH] take init_files to fs/file.c
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-05-16 17:22:20 -04:00
Roland McGrath
1f465f4e47 x86: user_regset_view table fix for ia32 on 64-bit
The user_regset_view table for the 32-bit regsets on the 64-bit build had
the wrong sizes for the FP regsets.  This bug had no user-visible effect
(just on kernel modules using the user_regset interfaces and the like).
But the fix is trivial and risk-free.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-05-13 19:40:20 +02:00
Ingo Molnar
89804c022f x86: fix csum_partial() export
Fix this symbol export problem:

    Building modules, stage 2.
    MODPOST 193 modules
    ERROR: "csum_partial" [fs/reiserfs/reiserfs.ko] undefined!
    make[1]: *** [__modpost] Error 1
    make: *** [modules] Error 2

This is due to a known weakness of symbol exports: if a symbol's
only in-core user is an EXPORT_SYMBOL from a lib-y section, the
symbol is not linked in.

The solution is to move the export to x8664_ksyms_64.c - but the real
solution would be to fix kbuild.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-05-13 19:38:47 +02:00
Andrew Morton
8c45a4e4f2 x86: early_init_centaur(): use set_cpu_cap()
arch/x86/kernel/setup_64.c:954: warning: passing argument 2 of 'set_bit' from incompatible pointer type

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-05-13 19:37:38 +02:00