Pull scheduler changes from Ingo Molnar:
"Bigger changes:
- sched/idle restructuring: they are WIP preparation for deeper
integration between the scheduler and idle state selection, by
Nicolas Pitre.
- add NUMA scheduling pseudo-interleaving, by Rik van Riel.
- optimize cgroup context switches, by Peter Zijlstra.
- RT scheduling enhancements, by Thomas Gleixner.
The rest is smaller changes, non-urgnt fixes and cleanups"
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (68 commits)
sched: Clean up the task_hot() function
sched: Remove double calculation in fix_small_imbalance()
sched: Fix broken setscheduler()
sparc64, sched: Remove unused sparc64_multi_core
sched: Remove unused mc_capable() and smt_capable()
sched/numa: Move task_numa_free() to __put_task_struct()
sched/fair: Fix endless loop in idle_balance()
sched/core: Fix endless loop in pick_next_task()
sched/fair: Push down check for high priority class task into idle_balance()
sched/rt: Fix picking RT and DL tasks from empty queue
trace: Replace hardcoding of 19 with MAX_NICE
sched: Guarantee task priority in pick_next_task()
sched/idle: Remove stale old file
sched: Put rq's sched_avg under CONFIG_FAIR_GROUP_SCHED
cpuidle/arm64: Remove redundant cpuidle_idle_call()
cpuidle/powernv: Remove redundant cpuidle_idle_call()
sched, nohz: Exclude isolated cores from load balancing
sched: Fix select_task_rq_fair() description comments
workqueue: Replace hardcoding of -20 and 19 with MIN_NICE and MAX_NICE
sys: Replace hardcoding of -20 and 19 with MIN_NICE and MAX_NICE
...
Pull perf changes from Ingo Molnar:
"Main changes:
Kernel side changes:
- Add SNB/IVB/HSW client uncore memory controller support (Stephane
Eranian)
- Fix various x86/P4 PMU driver bugs (Don Zickus)
Tooling, user visible changes:
- Add several futex 'perf bench' microbenchmarks (Davidlohr Bueso)
- Speed up thread map generation (Don Zickus)
- Introduce 'perf kvm --list-cmds' command line option for use by
scripts (Ramkumar Ramachandra)
- Print the evsel name in the annotate stdio output, prep to fix
support outputting annotation for multiple events, not just for the
first one (Arnaldo Carvalho de Melo)
- Allow setting preferred callchain method in .perfconfig (Jiri Olsa)
- Show in what binaries/modules 'perf probe's are set (Masami
Hiramatsu)
- Support distro-style debuginfo for uprobe in 'perf probe' (Masami
Hiramatsu)
Tooling, internal changes and fixes:
- Use tid in mmap/mmap2 events to find maps (Don Zickus)
- Record the reason for filtering an address_location (Namhyung Kim)
- Apply all filters to an addr_location (Namhyung Kim)
- Merge al->filtered with hist_entry->filtered in report/hists
(Namhyung Kim)
- Fix memory leak when synthesizing thread records (Namhyung Kim)
- Use ui__has_annotation() in 'report' (Namhyung Kim)
- hists browser refactorings to reuse code accross UIs (Namhyung Kim)
- Add support for the new DWARF unwinder library in elfutils (Jiri
Olsa)
- Fix build race in the generation of bison files (Jiri Olsa)
- Further streamline the feature detection display, trimming it a bit
to show just the libraries detected, using VF=1 gets a more verbose
output, showing the less interesting feature checks as well (Jiri
Olsa).
- Check compatible symtab type before loading dso (Namhyung Kim)
- Check return value of filename__read_debuglink() (Stephane Eranian)
- Move some hashing and fs related code from tools/perf/util/ to
tools/lib/ so that it can be used by more tools/ living utilities
(Borislav Petkov)
- Prepare DWARF unwinding code for using an elfutils alternative
unwinding library (Jiri Olsa)
- Fix DWARF unwind max_stack processing (Jiri Olsa)
- Add dwarf unwind 'perf test' entry (Jiri Olsa)
- 'perf probe' improvements including memory leak fixes, sharing the
intlist class with other tools, uprobes/kprobes code sharing and
use of ref_reloc_sym (Masami Hiramatsu)
- Shorten sample symbol resolving by adding cpumode to struct
addr_location (Arnaldo Carvalho de Melo)
- Fix synthesizing mmaps for threads (Don Zickus)
- Fix invalid output on event group stdio report (Namhyung Kim)
- Fixup header alignment in 'perf sched latency' output (Ramkumar
Ramachandra)
- Fix off-by-one error in 'perf timechart record' argv handling
(Ramkumar Ramachandra)
Tooling, cleanups:
- Remove unused thread__find_map function (Jiri Olsa)
- Remove unused simple_strtoul() function (Ramkumar Ramachandra)
Tooling, documentation updates:
- Update function names in debug messages (Ramkumar Ramachandra)
- Update some code references in design.txt (Ramkumar Ramachandra)
- Clarify load-latency information in the 'perf mem' docs (Andi
Kleen)
- Clarify x86 register naming in 'perf probe' docs (Andi Kleen)"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (96 commits)
perf tools: Remove unused simple_strtoul() function
perf tools: Update some code references in design.txt
perf evsel: Update function names in debug messages
perf tools: Remove thread__find_map function
perf annotate: Print the evsel name in the stdio output
perf report: Use ui__has_annotation()
perf tools: Fix memory leak when synthesizing thread records
perf tools: Use tid in mmap/mmap2 events to find maps
perf report: Merge al->filtered with hist_entry->filtered
perf symbols: Apply all filters to an addr_location
perf symbols: Record the reason for filtering an address_location
perf sched: Fixup header alignment in 'latency' output
perf timechart: Fix off-by-one error in 'record' argv handling
perf machine: Factor machine__find_thread to take tid argument
perf tools: Speed up thread map generation
perf kvm: introduce --list-cmds for use by scripts
perf ui hists: Pass evsel to hpp->header/width functions explicitly
perf symbols: Introduce thread__find_cpumode_addr_location
perf session: Change header.misc dump from decimal to hex
perf ui/tui: Reuse generic __hpp__fmt() code
...
Pull RCU updates from Ingo Molnar:
"Main changes:
- Torture-test changes, including refactoring of rcutorture and
introduction of a vestigial locktorture.
- Real-time latency fixes.
- Documentation updates.
- Miscellaneous fixes"
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (77 commits)
rcu: Provide grace-period piggybacking API
rcu: Ensure kernel/rcu/rcu.h can be sourced/used stand-alone
rcu: Fix sparse warning for rcu_expedited from kernel/ksysfs.c
notifier: Substitute rcu_access_pointer() for rcu_dereference_raw()
Documentation/memory-barriers.txt: Clarify release/acquire ordering
rcutorture: Save kvm.sh output to log
rcutorture: Add a lock_busted to test the test
rcutorture: Place kvm-test-1-run.sh output into res directory
rcutorture: Rename TREE_RCU-Kconfig.txt
locktorture: Add kvm-recheck.sh plug-in for locktorture
rcutorture: Gracefully handle NULL cleanup hooks
locktorture: Add vestigial locktorture configuration
rcutorture: Introduce "rcu" directory level underneath configs
rcutorture: Rename kvm-test-1-rcu.sh
rcutorture: Remove RCU dependencies from ver_functions.sh API
rcutorture: Create CFcommon file for common Kconfig parameters
rcutorture: Create config files for scripted test-the-test testing
rcutorture: Add an rcu_busted to test the test
locktorture: Add a lock-torture kernel module
rcutorture: Abstract kvm-recheck.sh
...
Pull core locking updates from Ingo Molnar:
"The biggest change is the MCS spinlock generalization changes from Tim
Chen, Peter Zijlstra, Jason Low et al. There's also lockdep
fixes/enhancements from Oleg Nesterov, in particular a false negative
fix related to lockdep_set_novalidate_class() usage"
* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (22 commits)
locking/mutex: Fix debug checks
locking/mutexes: Add extra reschedule point
locking/mutexes: Introduce cancelable MCS lock for adaptive spinning
locking/mutexes: Unlock the mutex without the wait_lock
locking/mutexes: Modify the way optimistic spinners are queued
locking/mutexes: Return false if task need_resched() in mutex_can_spin_on_owner()
locking: Move mcs_spinlock.h into kernel/locking/
m68k: Skip futex_atomic_cmpxchg_inatomic() test
futex: Allow architectures to skip futex_atomic_cmpxchg_inatomic() test
Revert "sched/wait: Suppress Sparse 'variable shadowing' warning"
lockdep: Change lockdep_set_novalidate_class() to use _and_name
lockdep: Change mark_held_locks() to check hlock->check instead of lockdep_no_validate
lockdep: Don't create the wrong dependency on hlock->check == 0
lockdep: Make held_lock->check and "int check" argument bool
locking/mcs: Allow architecture specific asm files to be used for contended case
locking/mcs: Order the header files in Kbuild of each architecture in alphabetical order
sched/wait: Suppress Sparse 'variable shadowing' warning
hung_task/Documentation: Fix hung_task_warnings description
locking/mcs: Allow architectures to hook in to contended paths
locking/mcs: Micro-optimize the MCS code, add extra comments
...
It its possible to configure your PAM stack to refuse login if audit
messages (about the login) were unable to be sent. This is common in
many distros and thus normal configuration of many containers. The PAM
modules determine if audit is enabled/disabled in the kernel based on
the return value from sending an audit message on the netlink socket.
If userspace gets back ECONNREFUSED it believes audit is disabled in the
kernel. If it gets any other error else it refuses to let the login
proceed.
Just about ever since the introduction of namespaces the kernel audit
subsystem has returned EPERM if the task sending a message was not in
the init user or pid namespace. So many forms of containers have never
worked if audit was enabled in the kernel.
BUT if the container was not in net_init then the kernel network code
would send ECONNREFUSED (instead of the audit code sending EPERM). Thus
by pure accident/dumb luck/bug if an admin configured the PAM stack to
reject all logins that didn't talk to audit, but then ran the login
untility in the non-init_net namespace, it would work!! Clearly this was
a bug, but it is a bug some people expected.
With the introduction of network namespace support in 3.14-rc1 the two
bugs stopped cancelling each other out. Now, containers in the
non-init_net namespace refused to let users log in (just like PAM was
configfured!) Obviously some people were not happy that what used to let
users log in, now didn't!
This fix is kinda hacky. We return ECONNREFUSED for all non-init
relevant namespaces. That means that not only will the old broken
non-init_net setups continue to work, now the broken non-init_pid or
non-init_user setups will 'work'. They don't really work, since audit
isn't logging things. But it's what most users want.
In 3.15 we should have patches to support not only the non-init_net
(3.14) namespace but also the non-init_pid and non-init_user namespace.
So all will be right in the world. This just opens the doors wide open
on 3.14 and hopefully makes users happy, if not the audit system...
Reported-by: Andre Tomt <andre@tomt.net>
Reported-by: Adam Richter <adam_richter2004@yahoo.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In commit 47a1b79630 ("tick/timekeeping: Call
update_wall_time outside the jiffies lock"), we moved to calling
clock_was_set() due to the fact that we were no longer holding
the timekeeping or jiffies lock.
However, there is still the problem that clock_was_set()
triggers an IPI, which cannot be done from the timer's hard irq
context, and will generate WARN_ON warnings.
Apparently in my earlier testing, I'm guessing I didn't bump the
dmesg log level, so I somehow missed the WARN_ONs.
Thus we need to revert back to calling clock_was_set_delayed().
Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1395963049-11923-1-git-send-email-john.stultz@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
my slides for the event trigger tutorial. I booted a 3.14-rc7 kernel
to perform what I wanted to teach and cut and paste it into my slides.
When I tried the traceon event trigger with a condition attached to it
(turns tracing on only if a field of the trigger event matches a condition
set by the user), nothing happened. Tracing would not turn on. I stopped
working on my presentation in order to find what was wrong.
It ended up being the way trace event triggers work when they have
conditions. Instead of copying the fields, the condition code just
looks at the fields that were copied into the ring buffer. This works
great, unless tracing is off. That's because when the event is reserved
on the ring buffer, the ring buffer returns a NULL pointer, this tells
the tracing code that the ring buffer is disabled. This ends up being
a problem for the traceon trigger if it is using this information to
check its condition.
Luckily the code that checks if tracing is on returns the ring buffer
to use (because the ring buffer is determined by the event file
also passed to that field). I was able to easily solve this bug by
checking in that helper function if the returned ring buffer entry
is NULL, and if so, also check the file flag if it has a trace event
trigger condition, and if so, to pass back a temp ring buffer to use.
This will allow the trace event trigger condition to still test the
event fields, but nothing will be recorded.
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Merge tag 'trace-fixes-v3.14-rc7-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fix from Steven Rostedt:
"While on my flight to Linux Collaboration Summit, I was working on my
slides for the event trigger tutorial. I booted a 3.14-rc7 kernel to
perform what I wanted to teach and cut and paste it into my slides.
When I tried the traceon event trigger with a condition attached to it
(turns tracing on only if a field of the trigger event matches a
condition set by the user), nothing happened. Tracing would not turn
on. I stopped working on my presentation in order to find what was
wrong.
It ended up being the way trace event triggers work when they have
conditions. Instead of copying the fields, the condition code just
looks at the fields that were copied into the ring buffer. This works
great, unless tracing is off. That's because when the event is
reserved on the ring buffer, the ring buffer returns a NULL pointer,
this tells the tracing code that the ring buffer is disabled. This
ends up being a problem for the traceon trigger if it is using this
information to check its condition.
Luckily the code that checks if tracing is on returns the ring buffer
to use (because the ring buffer is determined by the event file also
passed to that field). I was able to easily solve this bug by
checking in that helper function if the returned ring buffer entry is
NULL, and if so, also check the file flag if it has a trace event
trigger condition, and if so, to pass back a temp ring buffer to use.
This will allow the trace event trigger condition to still test the
event fields, but nothing will be recorded"
* tag 'trace-fixes-v3.14-rc7-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Fix traceon trigger condition to actually turn tracing on
While working on my tutorial for 2014 Linux Collaboration Summit
I found that the traceon trigger did not work when conditions were
used. The other triggers worked fine though. Looking into it, it
is because of the way the triggers use the ring buffer to store
the fields it will use for the condition. But if tracing is off, nothing
is stored in the buffer, and the tracepoint exits before calling the
trigger to test the condition. This is fine for all the triggers that
only work when tracing is on, but for traceon trigger that is to
work when tracing is off, nothing happens.
The fix is simple, just use a temp ring buffer to record the event
if tracing is off and the event has a trace event conditional trigger
enabled. The rest of the tracepoint code will work just fine, but
the tracepoint wont be recorded in the other buffers.
Cc: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Pull RCU update from Paul E. McKenney:
" [...] one late-breaking commit. This one was requested for 3.15 by Peter Zijlstra.
It is low risk because it adds a new in-kernel API with minimal changes to the
existing code. Those minimal changes are the addition of memory barriers and
ACCESS_ONCE() macro calls, neither of which should be able to break things.
This commit has passed significant rcutorture testing, with these additional
additions to rcutorture slated for 3.16. This commit has also been exposed to
-next testing. "
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Srikar Dronamraju reports that commit b0c29f79ec ("futexes: Avoid
taking the hb->lock if there's nothing to wake up") causes java threads
getting stuck on futexes when runing specjbb on a power7 numa box.
The cause appears to be that the powerpc spinlocks aren't using the same
ticket lock model that we use on x86 (and other) architectures, which in
turn result in the "spin_is_locked()" test in hb_waiters_pending()
occasionally reporting an unlocked spinlock even when there are pending
waiters.
So this reinstates Davidlohr Bueso's original explicit waiter counting
code, which I had convinced Davidlohr to drop in favor of figuring out
the pending waiters by just using the existing state of the spinlock and
the wait queue.
Reported-and-tested-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Original-code-by: Davidlohr Bueso <davidlohr@hp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
array index in the trace event format bogus. He supplied an elegant solution
that uses __stringify() and also removes the need for the event_storage
and event_storage_mutex and also cuts off a few K of overhead from
the trace events.
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Merge tag 'trace-fixes-v3.14-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull trace fix from Steven Rostedt:
"Vaibhav Nagarnaik discovered that since 3.10 a clean-up patch made the
array index in the trace event format bogus.
He supplied an elegant solution that uses __stringify() and also
removes the need for the event_storage and event_storage_mutex and
also cuts off a few K of overhead from the trace events"
* tag 'trace-fixes-v3.14-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Fix array size mismatch in format string
The following pattern is currently not well supported by RCU:
1. Make data element inaccessible to RCU readers.
2. Do work that probably lasts for more than one grace period.
3. Do something to make sure RCU readers in flight before #1 above
have completed.
Here are some things that could currently be done:
a. Do a synchronize_rcu() unconditionally at either #1 or #3 above.
This works, but imposes needless work and latency.
b. Post an RCU callback at #1 above that does a wakeup, then
wait for the wakeup at #3. This works well, but likely results
in an extra unneeded grace period. Open-coding this is also
a bit more semi-tricky code than would be good.
This commit therefore adds get_state_synchronize_rcu() and
cond_synchronize_rcu() APIs. Call get_state_synchronize_rcu() at #1
above and pass its return value to cond_synchronize_rcu() at #3 above.
This results in a call to synchronize_rcu() if no grace period has
elapsed between #1 and #3, but requires only a load, comparison, and
memory barrier if a full grace period did elapse.
Requested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
In event format strings, the array size is reported in two locations.
One in array subscript and then via the "size:" attribute. The values
reported there have a mismatch.
For e.g., in sched:sched_switch the prev_comm and next_comm character
arrays have subscript values as [32] where as the actual field size is
16.
name: sched_switch
ID: 301
format:
field:unsigned short common_type; offset:0; size:2; signed:0;
field:unsigned char common_flags; offset:2; size:1; signed:0;
field:unsigned char common_preempt_count; offset:3; size:1;signed:0;
field:int common_pid; offset:4; size:4; signed:1;
field:char prev_comm[32]; offset:8; size:16; signed:1;
field:pid_t prev_pid; offset:24; size:4; signed:1;
field:int prev_prio; offset:28; size:4; signed:1;
field:long prev_state; offset:32; size:8; signed:1;
field:char next_comm[32]; offset:40; size:16; signed:1;
field:pid_t next_pid; offset:56; size:4; signed:1;
field:int next_prio; offset:60; size:4; signed:1;
After bisection, the following commit was blamed:
92edca0 tracing: Use direct field, type and system names
This commit removes the duplication of strings for field->name and
field->type assuming that all the strings passed in
__trace_define_field() are immutable. This is not true for arrays, where
the type string is created in event_storage variable and field->type for
all array fields points to event_storage.
Use __stringify() to create a string constant for the type string.
Also, get rid of event_storage and event_storage_mutex that are not
needed anymore.
also, an added benefit is that this reduces the overhead of events a bit more:
text data bss dec hex filename
8424787 2036472 1302528 11763787 b3804b vmlinux
8420814 2036408 1302528 11759750 b37086 vmlinux.patched
Link: http://lkml.kernel.org/r/1392349908-29685-1-git-send-email-vnagarnaik@google.com
Cc: Laurent Chavey <chavey@google.com>
Cc: stable@vger.kernel.org # 3.10+
Signed-off-by: Vaibhav Nagarnaik <vnagarnaik@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Pull cgroup fix from Tejun Heo:
"One really late cgroup patch to fix error path in create_css().
Hitting this bug would be pretty rare but still possible and it gets
delayed we'd need to backport it through -stable anyway. It only
updates error path in create_css() and has low chance of new
breakages"
* 'for-3.14-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup: fix a failure path in create_css()
If online_css() fails, we should remove cgroup files belonging
to css->ss.
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Pull scheduler fixes from Ingo Molnar:
"Three small fixes"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/clock: Prevent tracing recursion in sched_clock_cpu()
stop_machine: Fix^2 race between stop_two_cpus() and stop_cpus()
sched/deadline: Deny unprivileged users to set/change SCHED_DEADLINE policy
OK, so commit:
1d8fe7dc80 ("locking/mutexes: Unlock the mutex without the wait_lock")
generates this boot warning when CONFIG_DEBUG_MUTEXES=y:
WARNING: CPU: 0 PID: 139 at /usr/src/linux-2.6/kernel/locking/mutex-debug.c:82 debug_mutex_unlock+0x155/0x180() DEBUG_LOCKS_WARN_ON(lock->owner != current)
And that makes sense, because as soon as we release the lock a
new owner can come in...
One would think that !__mutex_slowpath_needs_to_unlock()
implementations suffer the same, but for DEBUG we fall back to
mutex-null.h which has an unconditional 1 for that.
The mutex debug code requires the mutex to be unlocked after
doing the debug checks, otherwise it can find inconsistent
state.
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: jason.low2@hp.com
Link: http://lkml.kernel.org/r/20140312122442.GB27965@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The tmp value has been already calculated in:
scaled_busy_load_per_task =
(busiest->load_per_task * SCHED_POWER_SCALE) /
busiest->group_power;
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1394555166-22894-1-git-send-email-vincent.guittot@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
I decided to run my tests on linux-next, and my wakeup_rt tracer was
broken. After running a bisect, I found that the problem commit was:
linux-next commit c365c292d0
"sched: Consider pi boosting in setscheduler()"
And the reason the wake_rt tracer test was failing, was because it had
no RT task to trace. I first noticed this when running with
sched_switch event and saw that my RT task still had normal SCHED_OTHER
priority. Looking at the problem commit, I found:
- p->normal_prio = normal_prio(p);
- p->prio = rt_mutex_getprio(p);
With no
+ p->normal_prio = normal_prio(p);
+ p->prio = rt_mutex_getprio(p);
Reading what the commit is suppose to do, I realize that the p->prio
can't be set if the task is boosted with a higher prio, but the
p->normal_prio still needs to be set regardless, otherwise, when the
task is deboosted, it wont get the new priority.
The p->prio has to be set before "check_class_changed()" is called,
otherwise the class wont be changed.
Also added fix to newprio to include a check for deadline policy that
was missing. This change was suggested by Juri Lelli.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Cc: SebastianAndrzej Siewior <bigeasy@linutronix.de>
Cc: Juri Lelli <juri.lelli@gmail.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140306120438.638bfe94@gandalf.local.home
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull audit namespace fixes from Eric Biederman:
"Starting with 3.14-rc1 the audit code is faulty (think oopses and
races) with respect to how it computes the network namespace of which
socket to reply to, and I happened to notice by chance when reading
through the code.
My testing and the automated build bots don't find any problems with
these fixes"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
audit: Update kdoc for audit_send_reply and audit_list_rules_send
audit: Send replies in the proper network namespace.
audit: Use struct net not pid_t to remember the network namespce to reply in
Add in an extra reschedule in an attempt to avoid getting reschedule
the moment we've acquired the lock.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-zah5eyn9gu7qlgwh9r6n2anc@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The mutex->spin_mlock was introduced in order to ensure that only 1 thread
spins for lock acquisition at a time to reduce cache line contention. When
lock->owner is NULL and the lock->count is still not 1, the spinner(s) will
continually release and obtain the lock->spin_mlock. This can generate
quite a bit of overhead/contention, and also might just delay the spinner
from getting the lock.
This patch modifies the way optimistic spinners are queued by queuing before
entering the optimistic spinning loop as oppose to acquiring before every
call to mutex_spin_on_owner(). So in situations where the spinner requires
a few extra spins before obtaining the lock, then there will only be 1 spinner
trying to get the lock and it will avoid the overhead from unnecessarily
unlocking and locking the spin_mlock.
Signed-off-by: Jason Low <jason.low2@hp.com>
Cc: tglx@linutronix.de
Cc: riel@redhat.com
Cc: akpm@linux-foundation.org
Cc: davidlohr@hp.com
Cc: hpa@zytor.com
Cc: andi@firstfloor.org
Cc: aswin@hp.com
Cc: scott.norton@hp.com
Cc: chegu_vinod@hp.com
Cc: Waiman.Long@hp.com
Cc: paulmck@linux.vnet.ibm.com
Cc: torvalds@linux-foundation.org
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1390936396-3962-3-git-send-email-jason.low2@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The mcs_spinlock code is not meant (or suitable) as a generic locking
primitive, therefore take it away from the normal includes and place
it in kernel/locking/.
This way the locking primitives implemented there can use it as part
of their implementation but we do not risk it getting used
inapropriately.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-byirmpamgr7h25m5kyavwpzx@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Check for fair tasks number to decide, that we've pulled a task.
rq's nr_running may contain throttled RT tasks.
Signed-off-by: Kirill Tkhai <ktkhai@parallels.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1394118975.19290.104.camel@tkhai
Signed-off-by: Ingo Molnar <mingo@kernel.org>
1) Single cpu machine case.
When rq has only RT tasks, but no one of them can be picked
because of throttling, we enter in endless loop.
pick_next_task_{dl,rt} return NULL.
In pick_next_task_fair() we permanently go to retry
if (rq->nr_running != rq->cfs.h_nr_running)
return RETRY_TASK;
(rq->nr_running is not being decremented when rt_rq becomes
throttled).
No chances to unthrottle any rt_rq or to wake fair here,
because of rq is locked permanently and interrupts are
disabled.
2) In case of SMP this can cause a hang too. Although we unlock
rq in idle_balance(), interrupts are still disabled.
The solution is to check for available tasks in DL and RT
classes instead of checking for sum.
Signed-off-by: Kirill Tkhai <ktkhai@parallels.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1394098321.19290.11.camel@tkhai
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We close idle_exit_fair() bracket in case of we've pulled something or we've received
task of high priority class.
Signed-off-by: Kirill Tkhai <ktkhai@parallels.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Link: http://lkml.kernel.org/r/1394098315.19290.10.camel@tkhai
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The problems:
1) We check for rt_nr_running before call of put_prev_task().
If previous task is RT, its rt_rq may become throttled
and dequeued after this call.
In case of p is from rt->rq this just causes picking a task
from throttled queue, but in case of its rt_rq is child
we are guaranteed catch BUG_ON.
2) The same with deadline class. The only difference we operate
on only dl_rq.
This patch fixes all the above problems and it adds a small skip in the
DL update like we've already done for RT class:
if (unlikely((s64)delta_exec <= 0))
return;
This will optimize sequential update_curr_dl() calls a little.
Signed-off-by: Kirill Tkhai <ktkhai@parallels.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@gmail.com>
Link: http://lkml.kernel.org/r/1393946746.3643.3.camel@tkhai
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Recent issues with user space callchains processing within
page fault handler tracing showed as Peter said 'there's
just too much fail surface'.
The user space stack dump is just another source of the this issue.
Related list discussions:
http://marc.info/?t=139302086500001&r=1&w=2http://marc.info/?t=139301437300003&r=1&w=2
Suggested-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1393775800-13524-3-git-send-email-jolsa@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Recent issues with user space callchains processing within
page fault handler tracing showed as Peter said 'there's
just too much fail surface'.
Related list discussions:
http://marc.info/?t=139302086500001&r=1&w=2http://marc.info/?t=139301437300003&r=1&w=2
Suggested-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1393775800-13524-2-git-send-email-jolsa@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Prevent tracing of preempt_disable/enable() in sched_clock_cpu().
When CONFIG_DEBUG_PREEMPT is enabled, preempt_disable/enable() are
traced and this causes trace_clock() users (and probably others) to
go into an infinite recursion. Systems with a stable sched_clock()
are not affected.
This problem is similar to that fixed by upstream commit 95ef1e5292
("KVM guest: prevent tracing recursion with kvmclock").
Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1394083528.4524.3.camel@nexus
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We must use smp_call_function_single(.wait=1) for the
irq_cpu_stop_queue_work() to ensure the queueing is actually done under
stop_cpus_lock. Without this we could have dropped the lock by the time
we do the queueing and get the race we tried to fix.
Fixes: 7053ea1a34 ("stop_machine: Fix race between stop_two_cpus() and stop_cpus()")
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20140228123905.GK3104@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Deny the use of SCHED_DEADLINE policy to unprivileged users.
Even if root users can set the policy for normal users, we
don't want the latter to be able to change their parameters
(safest behavior).
Signed-off-by: Juri Lelli <juri.lelli@gmail.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1393844961-18097-1-git-send-email-juri.lelli@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
GFP_THISNODE is for callers that implement their own clever fallback to
remote nodes. It restricts the allocation to the specified node and
does not invoke reclaim, assuming that the caller will take care of it
when the fallback fails, e.g. through a subsequent allocation request
without GFP_THISNODE set.
However, many current GFP_THISNODE users only want the node exclusive
aspect of the flag, without actually implementing their own fallback or
triggering reclaim if necessary. This results in things like page
migration failing prematurely even when there is easily reclaimable
memory available, unless kswapd happens to be running already or a
concurrent allocation attempt triggers the necessary reclaim.
Convert all callsites that don't implement their own fallback strategy
to __GFP_THISNODE. This restricts the allocation a single node too, but
at the same time allows the allocator to enter the slowpath, wake
kswapd, and invoke direct reclaim if necessary, to make the allocation
happen when memory is full.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Jan Stancek <jstancek@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The kbuild test robot reported:
> tree: git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace.git for-next
> head: 6f285b19d0
> commit: 6f285b19d0 [2/2] audit: Send replies in the proper network namespace.
> reproduce: make htmldocs
>
> >> Warning(kernel/audit.c:575): No description found for parameter 'request_skb'
> >> Warning(kernel/audit.c:575): Excess function parameter 'portid' description in 'audit_send_reply'
> >> Warning(kernel/auditfilter.c:1074): No description found for parameter 'request_skb'
> >> Warning(kernel/auditfilter.c:1074): Excess function parameter 'portid' description in 'audit_list_rules_s
Which was caused by my failure to update the kdoc annotations when I
updated the functions. Fix that small oversight now.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Pull cgroup fixes from Tejun Heo:
"Two cpuset locking fixes from Li. Both tagged for -stable"
* 'for-3.14-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cpuset: fix a race condition in __cpuset_node_allowed_softwall()
cpuset: fix a locking issue in cpuset_migrate_mm()
Developers would say they put a trace_printk() before and after the trace
event but when they enable it (and the trace event said it was enabled) they
would see the trace_printks but not the trace event.
I was not able to reproduce this, but that's because I wasn't looking at
the right location. Recently, another bug came up that showed the issue.
If your kernel supports signed modules but allows for non-signed modules
to be loaded, then when one is, the kernel will silently set the
MODULE_FORCED taint on the module. Although, this taint happens without
the need for insmod --force or anything of the kind, it labels the
module with that taint anyway.
If this tainted module has tracepoints, the tracepoints will be ignored
because of the MODULE_FORCED taint. But no error message will be
displayed. Worse yet, the event infrastructure will still be created
letting users enable the trace event represented by the tracepoint,
although that event will never actually be enabled. This is because
the tracepoint infrastructure allows for non-existing tracepoints to
be enabled for new modules to arrive and have their tracepoints set.
Although there are several things wrong with the above, this change
only addresses the creation of the trace event files for tracepoints
that are not created when a module is loaded and is tainted. This change
will print an error message about the module being tainted and not the
trace events will not be created, and it does not create the trace event
infrastructure.
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Merge tag 'trace-fixes-v3.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fix from Steven Rostedt:
"In the past, I've had lots of reports about trace events not working.
Developers would say they put a trace_printk() before and after the
trace event but when they enable it (and the trace event said it was
enabled) they would see the trace_printks but not the trace event.
I was not able to reproduce this, but that's because I wasn't looking
at the right location. Recently, another bug came up that showed the
issue.
If your kernel supports signed modules but allows for non-signed
modules to be loaded, then when one is, the kernel will silently set
the MODULE_FORCED taint on the module. Although, this taint happens
without the need for insmod --force or anything of the kind, it labels
the module with that taint anyway.
If this tainted module has tracepoints, the tracepoints will be
ignored because of the MODULE_FORCED taint. But no error message will
be displayed. Worse yet, the event infrastructure will still be
created letting users enable the trace event represented by the
tracepoint, although that event will never actually be enabled. This
is because the tracepoint infrastructure allows for non-existing
tracepoints to be enabled for new modules to arrive and have their
tracepoints set.
Although there are several things wrong with the above, this change
only addresses the creation of the trace event files for tracepoints
that are not created when a module is loaded and is tainted. This
change will print an error message about the module being tainted and
not the trace events will not be created, and it does not create the
trace event infrastructure"
* tag 'trace-fixes-v3.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Do not add event files for modules that fail tracepoints
Pull irq fixes from Thomas Gleixner:
- a bugfix for a long standing waitqueue race
- a trivial fix for a missing include
* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
genirq: Include missing header file in irqdomain.c
genirq: Remove racy waitqueue_active check
If a module fails to add its tracepoints due to module tainting, do not
create the module event infrastructure in the debugfs directory. As the events
will not work and worse yet, they will silently fail, making the user wonder
why the events they enable do not display anything.
Having a warning on module load and the events not visible to the users
will make the cause of the problem much clearer.
Link: http://lkml.kernel.org/r/20140227154923.265882695@goodmis.org
Fixes: 6d723736e4 "tracing/events: add support for modules to TRACE_EVENT"
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: stable@vger.kernel.org # 2.6.31+
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Pull scheduler fixes from Ingo Molnar:
"Misc fixes, most of them SCHED_DEADLINE fallout"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/deadline: Prevent rt_time growth to infinity
sched/deadline: Switch CPU's presence test order
sched/deadline: Cleanup RT leftovers from {inc/dec}_dl_migration
sched: Fix double normalization of vruntime
If an architecture has futex_atomic_cmpxchg_inatomic() implemented and there
is no runtime check necessary, allow to skip the test within futex_init().
This allows to get rid of some code which would always give the same result,
and also allows the compiler to optimize a couple of if statements away.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Finn Thain <fthain@telegraphics.com.au>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Link: http://lkml.kernel.org/r/20140302120947.GA3641@osiris
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Pull perf fixes from Ingo Molnar:
"Misc fixes, most of them on the tooling side"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf tools: Fix strict alias issue for find_first_bit
perf tools: fix BFD detection on opensuse
perf: Fix hotplug splat
perf/x86: Fix event scheduling
perf symbols: Destroy unused symsrcs
perf annotate: Check availability of annotate when processing samples
In perverse cases of file descriptor passing the current network
namespace of a process and the network namespace of a socket used by
that socket may differ. Therefore use the network namespace of the
appropiate socket to ensure replies always go to the appropiate
socket.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
In struct audit_netlink_list and audit_reply add a reference to the
network namespace of the caller and remove the userspace pid of the
caller. This cleanly remembers the callers network namespace, and
removes a huge class of races and nasty failure modes that can occur
when attempting to relook up the callers network namespace from a
pid_t (including the caller's network namespace changing, pid
wraparound, and the pid simply not being present).
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
