15755 Commits

Author SHA1 Message Date
Joonsoo Kim
f1c4069e1d mm, vmalloc: export vmap_area_list, instead of vmlist
Although our intention is to unexport internal structure entirely, but
there is one exception for kexec.  kexec dumps address of vmlist and
makedumpfile uses this information.

We are about to remove vmlist, then another way to retrieve information
of vmalloc layer is needed for makedumpfile.  For this purpose, we
export vmap_area_list, instead of vmlist.

Signed-off-by: Joonsoo Kim <js1304@gmail.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Dave Anderson <anderson@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Atsushi Kumagai <kumagai-atsushi@mxc.nes.nec.co.jp>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-29 15:54:34 -07:00
Josh Triplett
146732ce10 fs: don't compile in drop_caches.c when CONFIG_SYSCTL=n
drop_caches.c provides code only invokable via sysctl, so don't compile it
in when CONFIG_SYSCTL=n.

Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-29 15:54:33 -07:00
Michal Hocko
6d2488f64a cgroup: remove css_get_next
Now that we have generic and well ordered cgroup tree walkers there is
no need to keep css_get_next in the place.

Signed-off-by: Michal Hocko <mhocko@suse.cz>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Li Zefan <lizefan@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Ying Han <yinghan@google.com>
Cc: Tejun Heo <htejun@gmail.com>
Cc: Glauber Costa <glommer@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-29 15:54:33 -07:00
Jiang Liu
e07cee23e6 mm,kexec: use common help functions to free reserved pages
Use common help functions to free reserved pages.

Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Reviewed-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-29 15:54:31 -07:00
Chen Gang
12b2f117f3 kernel/audit_tree.c: tree will leak memory when failure occurs in audit_trim_trees()
audit_trim_trees() calls get_tree().  If a failure occurs we must call
put_tree().

[akpm@linux-foundation.org: run put_tree() before mutex_lock() for small scalability improvement]
Signed-off-by: Chen Gang <gang.chen@asianux.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-29 15:54:26 -07:00
Chen Gang
373e0f3408 kernel/auditfilter.c: tree and watch will memory leak when failure occurs
In audit_data_to_entry() when a failure occurs we must check and free
the tree and watch to avoid a memory leak.

  test:
    plan:
      test command:
        "auditctl -a exit,always -w /etc -F auid=-1"
        (on fedora17, need modify auditctl to let "-w /etc" has effect)
      running:
        under fedora17 x86_64, 2 CPUs 3.20GHz, 2.5GB RAM.
        let 15 auditctl processes continue running at the same time.
      monitor command:
        watch -d -n 1 "cat /proc/meminfo | awk '{print \$2}' \
          | head -n 4 | xargs \
          | awk '{print \"used \",\$1 - \$2 - \$3 - \$4}'"

    result:
      for original version:
        will use up all memory, within 3 hours.
        kill all auditctl, the memory still does not free.
      for new version (apply this patch):
        after 14 hours later, not find issues.

Signed-off-by: Chen Gang <gang.chen@asianux.com>
Cc: Eric Paris <eparis@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-29 15:54:26 -07:00
Gao feng
dde5b7d6e7 audit: remove unnecessary #if CONFIG_AUDIT
The files which include kernel/audit.h are complied only when
CONFIG_AUDIT is set.

Just like audit_pid, there is no need to surround audit_ever_enabled
with CONFIG_AUDIT.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-29 15:54:26 -07:00
Gao feng
374c586d95 audit: remove duplicate export of audit_enabled
audit_enabled has already been exported in include/linux/audit.h.  and
kernel/audit.h includes include/linux/audit.h, no need to export
aduit_enabled again in kernel/audit.h

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-29 15:54:26 -07:00
Gao feng
13f51e1c3f audit: don't check if kauditd is valid every time
We only need to check if kauditd is valid after we start it, if kauditd
is invalid, we will set kauditd_task to NULL.  So next time, we will
start kauditd again.

It means if kauditd_task is not NULL,it must be valid.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Cc: Eric Paris <eparis@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-29 15:54:26 -07:00
Rakib Mullick
3f68613f39 kernel/auditsc.c: use kzalloc instead of kmalloc+memset
In audit_alloc_context() use kzalloc instead of kmalloc+memset.  Also
rename audit_zero_context() to audit_set_context(), to represent it's
inner workings properly.

[akpm@linux-foundation.org: remove audit_set_context() altogether - fold it into its caller]
Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-29 15:54:26 -07:00
Oleg Nesterov
b5c5442bb6 kthread: kill task_get_live_kthread()
task_get_live_kthread() looks confusing and unneeded.  It does
get_task_struct() but only kthread_stop() needs this, it can be called
even if the calller doesn't have a reference when we know that this
kthread can't exit until we do kthread_stop().

kthread_park() and kthread_unpark() do not need get_task_struct(), the
callers already have the reference.  And it can not help if we can race
with the exiting kthread anyway, kthread_park() can hang forever in this
case.

Change kthread_park() and kthread_unpark() to use to_live_kthread(),
change kthread_stop() to do get_task_struct() by hand and remove
task_get_live_kthread().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-29 15:54:25 -07:00
Oleg Nesterov
4ecdafc808 kthread: introduce to_live_kthread()
"k->vfork_done != NULL" with a barrier() after to_kthread(k) in
task_get_live_kthread(k) looks unclear, and sub-optimal because we load
->vfork_done twice.

All we need is to ensure that we do not return to_kthread(NULL).  Add a
new trivial helper which loads/checks ->vfork_done once, this also looks
more understandable.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-29 15:54:25 -07:00
Linus Torvalds
9e8529afc4 Tracing updates for Linux 3.10
Along with the usual minor fixes and clean ups there are a few major
 changes with this pull request.
 
 1) Multiple buffers for the ftrace facility
 
 This feature has been requested by many people over the last few years.
 I even heard that Google was about to implement it themselves. I finally
 had time and cleaned up the code such that you can now create multiple
 instances of the ftrace buffer and have different events go to different
 buffers. This way, a low frequency event will not be lost in the noise
 of a high frequency event.
 
 Note, currently only events can go to different buffers, the tracers
 (ie. function, function_graph and the latency tracers) still can only
 be written to the main buffer.
 
 2) The function tracer triggers have now been extended.
 
 The function tracer had two triggers. One to enable tracing when a
 function is hit, and one to disable tracing. Now you can record a
 stack trace on a single (or many) function(s), take a snapshot of the
 buffer (copy it to the snapshot buffer), and you can enable or disable
 an event to be traced when a function is hit.
 
 3) A perf clock has been added.
 
 A "perf" clock can be chosen to be used when tracing. This will cause
 ftrace to use the same clock as perf uses, and hopefully this will make
 it easier to interleave the perf and ftrace data for analysis.
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Merge tag 'trace-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "Along with the usual minor fixes and clean ups there are a few major
  changes with this pull request.

   1) Multiple buffers for the ftrace facility

  This feature has been requested by many people over the last few
  years.  I even heard that Google was about to implement it themselves.
  I finally had time and cleaned up the code such that you can now
  create multiple instances of the ftrace buffer and have different
  events go to different buffers.  This way, a low frequency event will
  not be lost in the noise of a high frequency event.

  Note, currently only events can go to different buffers, the tracers
  (ie function, function_graph and the latency tracers) still can only
  be written to the main buffer.

   2) The function tracer triggers have now been extended.

  The function tracer had two triggers.  One to enable tracing when a
  function is hit, and one to disable tracing.  Now you can record a
  stack trace on a single (or many) function(s), take a snapshot of the
  buffer (copy it to the snapshot buffer), and you can enable or disable
  an event to be traced when a function is hit.

   3) A perf clock has been added.

  A "perf" clock can be chosen to be used when tracing.  This will cause
  ftrace to use the same clock as perf uses, and hopefully this will
  make it easier to interleave the perf and ftrace data for analysis."

* tag 'trace-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (82 commits)
  tracepoints: Prevent null probe from being added
  tracing: Compare to 1 instead of zero for is_signed_type()
  tracing: Remove obsolete macro guard _TRACE_PROFILE_INIT
  ftrace: Get rid of ftrace_profile_bits
  tracing: Check return value of tracing_init_dentry()
  tracing: Get rid of unneeded key calculation in ftrace_hash_move()
  tracing: Reset ftrace_graph_filter_enabled if count is zero
  tracing: Fix off-by-one on allocating stat->pages
  kernel: tracing: Use strlcpy instead of strncpy
  tracing: Update debugfs README file
  tracing: Fix ftrace_dump()
  tracing: Rename trace_event_mutex to trace_event_sem
  tracing: Fix comment about prefix in arch_syscall_match_sym_name()
  tracing: Convert trace_destroy_fields() to static
  tracing: Move find_event_field() into trace_events.c
  tracing: Use TRACE_MAX_PRINT instead of constant
  tracing: Use pr_warn_once instead of open coded implementation
  ring-buffer: Add ring buffer startup selftest
  tracing: Bring Documentation/trace/ftrace.txt up to date
  tracing: Add "perf" trace_clock
  ...

Conflicts:
	kernel/trace/ftrace.c
	kernel/trace/trace.c
2013-04-29 13:55:38 -07:00
Al Viro
8e0bcc7222 fix a leak in /proc/schedstats
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-04-29 15:41:45 -04:00
Linus Torvalds
916bb6d76d Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking changes from Ingo Molnar:
 "The most noticeable change are mutex speedups from Waiman Long, for
  higher loads.  These scalability changes should be most noticeable on
  larger server systems.

  There are also cleanups, fixes and debuggability improvements."

* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  lockdep: Consolidate bug messages into a single print_lockdep_off() function
  lockdep: Print out additional debugging advice when we hit lockdep BUGs
  mutex: Back out architecture specific check for negative mutex count
  mutex: Queue mutex spinners with MCS lock to reduce cacheline contention
  mutex: Make more scalable by doing less atomic operations
  mutex: Move mutex spinning code from sched/core.c back to mutex.c
  locking/rtmutex/tester: Set correct permissions on sysfs files
  lockdep: Remove unnecessary 'hlock_next' variable
2013-04-29 08:21:37 -07:00
Li Zhong
6296ace467 nohz: Protect smp_processor_id() in tick_nohz_task_switch()
I saw following error when testing the latest nohz code on
Power:

[   85.295384] BUG: using smp_processor_id() in preemptible [00000000] code: rsyslogd/3493
[   85.295396] caller is .tick_nohz_task_switch+0x1c/0xb8
[   85.295402] Call Trace:
[   85.295408] [c0000001fababab0] [c000000000012dc4] .show_stack+0x110/0x25c (unreliable)
[   85.295420] [c0000001fababba0] [c0000000007c4b54] .dump_stack+0x20/0x30
[   85.295430] [c0000001fababc10] [c00000000044eb74] .debug_smp_processor_id+0xf4/0x124
[   85.295438] [c0000001fababca0] [c0000000000d7594] .tick_nohz_task_switch+0x1c/0xb8
[   85.295447] [c0000001fababd20] [c0000000000b9748] .finish_task_switch+0x13c/0x160
[   85.295455] [c0000001fababdb0] [c0000000000bbe50] .schedule_tail+0x50/0x124
[   85.295463] [c0000001fababe30] [c000000000009dc8] .ret_from_fork+0x4/0x54

The code below moves the test into local_irq_save/restore
section to avoid the above complaint.

Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1367119558.6391.34.camel@ThinkPad-T5421.cn.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-29 13:17:33 +02:00
Li Zefan
2a0010af17 cpuset: fix compile warning when CONFIG_SMP=n
Reported by Fengguang's kbuild test robot:

kernel/cpuset.c:787: warning: 'generate_sched_domains' defined but not used

Introduced by commit e0e80a02e5701c8790bd348ab59edb154fbda60b
("cpuset: use rebuild_sched_domains() in cpuset_hotplug_workfn()),
which removed generate_sched_domains() from cpuset_hotplug_workfn().

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2013-04-27 19:55:04 -07:00
Rafael J. Wysocki
355c63e5ac Merge branch 'pm-assorted'
* pm-assorted:
  PM / OPP: add documentation to RCU head in struct opp
  PM / sleep: invalidate TEST_CPUS and TEST_CORE support for freeze state
  PM / sleep: add TEST_PLATFORM support for freeze state
2013-04-28 01:54:29 +02:00
Linus Torvalds
e09d13c4c8 Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fix from Ingo Molnar:
 "This fix adds missing RCU read protection"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  events: Protect access via task_subsys_state_check()
2013-04-27 10:08:09 -07:00
Li Zefan
5b16c2a493 cpuset: fix cpu hotplug vs rebuild_sched_domains() race
rebuild_sched_domains() might pass doms with offlined cpu to
partition_sched_domains(), which results in an oops:

general protection fault: 0000 [#1] SMP
...
RIP: 0010:[<ffffffff81077a1e>]  [<ffffffff81077a1e>] get_group+0x6e/0x90
...
Call Trace:
 [<ffffffff8107f07c>] build_sched_domains+0x70c/0xcb0
 [<ffffffff8107f2a7>] ? build_sched_domains+0x937/0xcb0
 [<ffffffff81173f64>] ? kfree+0xe4/0x1b0
 [<ffffffff8107f6e0>] ? partition_sched_domains+0xc0/0x470
 [<ffffffff8107f905>] partition_sched_domains+0x2e5/0x470
 [<ffffffff8107f6e0>] ? partition_sched_domains+0xc0/0x470
 [<ffffffff810c9007>] ? generate_sched_domains+0xc7/0x530
 [<ffffffff810c94a8>] rebuild_sched_domains_locked+0x38/0x70
 [<ffffffff810cb4a4>] cpuset_write_resmask+0x1a4/0x500
 [<ffffffff810c8700>] ? cpuset_mount+0xe0/0xe0
 [<ffffffff810c7f50>] ? cpuset_read_u64+0x100/0x100
 [<ffffffff810be890>] ? cgroup_iter_next+0x90/0x90
 [<ffffffff810cb300>] ? cpuset_css_offline+0x70/0x70
 [<ffffffff810c1a73>] cgroup_file_write+0x133/0x2e0
 [<ffffffff8118995b>] vfs_write+0xcb/0x130
 [<ffffffff8118a174>] sys_write+0x64/0xa0

Reported-by: Li Zhong <zhong@linux.vnet.ibm.com>
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2013-04-27 06:52:43 -07:00
Li Zhong
e0e80a02e5 cpuset: use rebuild_sched_domains() in cpuset_hotplug_workfn()
In cpuset_hotplug_workfn(), partition_sched_domains() is called without
hotplug lock held, which is actually needed (stated in the function
header of partition_sched_domains()).

This patch tries to use rebuild_sched_domains() to solve the above
issue, and makes the code looks a little simpler.

Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2013-04-27 06:52:43 -07:00
Ingo Molnar
a1412ec539 Merge branch 'timers/nohz-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks into timers/nohz
Pull more full-dynticks updates from Frederic Weisbecker:

 * Get rid of the passive dependency on VIRT_CPU_ACCOUNTING_GEN (finally!)
 * Preparation patch to remove the dependency on CONFIG_64BITS

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-27 09:16:06 +02:00
Li Zefan
7ef70e4873 cgroup: restore the call to eventfd->poll()
I mistakenly removed the call to eventfd->poll() while I was actually
intending to remove the return value...

Calling evenfd->poll() will hook cgroup_event_wake() to the poll
waitqueue, which will be called to unregister eventfd when rmdir a
cgroup or close eventfd.

Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2013-04-26 11:58:03 -07:00
Li Zefan
cc20e01cd6 cgroup: fix use-after-free when umounting cgroupfs
Try:
  # mount -t cgroup xxx /cgroup
  # mkdir /cgroup/sub && rmdir /cgroup/sub && umount /cgroup

And you might see this:

ida_remove called for id=1 which is not allocated.

It's because cgroup_kill_sb() is called to destroy root->cgroup_ida
and free cgrp->root before ida_simple_removed() is called. What's
worse is we're accessing cgrp->root while it has been freed.

Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2013-04-26 11:58:02 -07:00
Frederic Weisbecker
c58b0df12a nohz: Select VIRT_CPU_ACCOUNTING_GEN from full dynticks config
Turn the full dynticks passive dependency on VIRT_CPU_ACCOUNTING_GEN
to an active one.

The full dynticks Kconfig is currently hidden behind the full dynticks
cputime accounting, which is an awkward and counter-intuitive layout:
the user first has to select the dynticks cputime accounting in order
to make the full dynticks feature to be visible.

We definetly want it the other way around. The usual way to perform
this kind of active dependency is use "select" on the depended target.
Now we can't use the Kconfig "select" instruction when the target is
a "choice".

So this patch inspires on how the RCU subsystem Kconfig interact
with its dependencies on SMP and PREEMPT: we make sure that cputime
accounting can't propose another option than VIRT_CPU_ACCOUNTING_GEN
when NO_HZ_FULL is selected by using the right "depends on" instruction
for each cputime accounting choices.

v2: Keep full dynticks cputime accounting available even without
full dynticks, as per Paul McKenney's suggestion.

Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-26 18:56:59 +02:00
Vincent Guittot
25f55d9d01 sched: Fix init NOHZ_IDLE flag
On my SMP platform which is made of 5 cores in 2 clusters, I
have the nr_busy_cpu field of sched_group_power struct that is
not null when the platform is fully idle - which makes the
scheduler unhappy.

The root cause is:

During the boot sequence, some CPUs reach the idle loop and set
their NOHZ_IDLE flag while waiting for others CPUs to boot. But
the nr_busy_cpus field is initialized later with the assumption
that all CPUs are in the busy state whereas some CPUs have
already set their NOHZ_IDLE flag.

More generally, the NOHZ_IDLE flag must be initialized when new
sched_domains are created in order to ensure that NOHZ_IDLE and
nr_busy_cpus are aligned.

This condition can be ensured by adding a synchronize_rcu()
between the destruction of old sched_domains and the creation of
new ones so the NOHZ_IDLE flag will not be updated with old
sched_domain once it has been initialized. But this solution
introduces a additionnal latency in the rebuild sequence that is
called during cpu hotplug.

As suggested by Frederic Weisbecker, another solution is to have
the same rcu lifecycle for both NOHZ_IDLE and sched_domain
struct. A new nohz_idle field is added to sched_domain so both
status and sched_domain will share the same RCU lifecycle and
will be always synchronized. In addition, there is no more need
to protect nohz_idle against concurrent access as it is only
modified by 2 exclusive functions called by local cpu.

This solution has been prefered to the creation of a new struct
with an extra pointer indirection for sched_domain.

The synchronization is done at the cost of :

 - An additional indirection and a rcu_dereference for accessing nohz_idle.
 - We use only the nohz_idle field of the top sched_domain.

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: linaro-kernel@lists.linaro.org
Cc: peterz@infradead.org
Cc: fweisbec@gmail.com
Cc: pjt@google.com
Cc: rostedt@goodmis.org
Cc: efault@gmx.de
Link: http://lkml.kernel.org/r/1366729142-14662-1-git-send-email-vincent.guittot@linaro.org
[ Fixed !NO_HZ build bug. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-26 12:13:44 +02:00
Ingo Molnar
47aa8b6cbc nohz: Reduce overhead under high-freq idling patterns
One testbox of mine (Intel Nehalem, 16-way) uses MWAIT for its idle routine,
which apparently can break out of its idle loop rather frequently, with
high frequency.

In that case NO_HZ_FULL=y kernels show high ksoftirqd overhead and constant
context switching, because tick_nohz_stop_sched_tick() will, if
delta_jiffies == 0, mis-identify this as a timer event - activating the
TIMER_SOFTIRQ, which wakes up ksoftirqd.

Fix this by treating delta_jiffies == 0 the same way we treat other short
wakeups, delta_jiffies == 1.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-26 10:13:42 +02:00
Dave Jones
2c52283662 lockdep: Consolidate bug messages into a single print_lockdep_off() function
Also add some missing printk levels.

Signed-off-by: Dave Jones <davej@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20130425174002.GA26769@redhat.com
[ Tweaked the messages a bit. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-26 08:37:22 +02:00
Dave Jones
199e371f59 lockdep: Print out additional debugging advice when we hit lockdep BUGs
We occasionally get reports of these BUGs being hit, and the
stack trace doesn't necessarily always tell us what we need to
know about why we are hitting those limits.

If users start attaching /proc/lock_stats to reports we may have
more of a clue what's going on.

Signed-off-by: Dave Jones <davej@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20130423163403.GA12839@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-26 08:36:33 +02:00
Thomas Gleixner
6f7a05d701 clockevents: Set dummy handler on CPU_DEAD shutdown
Vitaliy reported that a per cpu HPET timer interrupt crashes the
system during hibernation. What happens is that the per cpu HPET timer
gets shut down when the nonboot cpus are stopped. When the nonboot
cpus are onlined again the HPET code sets up the MSI interrupt which
fires before the clock event device is registered. The event handler
is still set to hrtimer_interrupt, which then crashes the machine due
to highres mode not being active.

See http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=700333

There is no real good way to avoid that in the HPET code. The HPET
code alrady has a mechanism to detect spurious interrupts when event
handler == NULL for a similar reason.

We can handle that in the clockevent/tick layer and replace the
previous functional handler with a dummy handler like we do in
tick_setup_new_device().

The original clockevents code did this in clockevents_exchange_device(),
but that got removed by commit 7c1e76897 (clockevents: prevent
clockevent event_handler ending up handler_noop) which forgot to fix
it up in tick_shutdown(). Same issue with the broadcast device.

Reported-by: Vitaliy Fillipov <vitalif@yourcmc.ru>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: stable@vger.kernel.org
Cc: 700333@bugs.debian.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-04-25 13:57:04 +02:00
Thomas Gleixner
6402c7dc2a Merge branch 'linus' into timers/core
Reason: Get upstream fixes before adding conflicting code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-04-24 20:33:54 +02:00
Frederic Weisbecker
65e709dc0c nohz: Remove full dynticks' superfluous dependency on RCU tree
Remove the dependency on (TREE_RCU || TREE_PREEMPT_RCU). The full
dynticks option already depends on SMP which implies
(whatever flavour of) RCU tree config anyway.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-24 16:17:36 +02:00
Joonsoo Kim
e02e60c109 sched: Prevent to re-select dst-cpu in load_balance()
Commit 88b8dac0 makes load_balance() consider other cpus in its
group. But, in that, there is no code for preventing to
re-select dst-cpu. So, same dst-cpu can be selected over and
over.

This patch add functionality to load_balance() in order to
exclude cpu which is selected once. We prevent to re-select
dst_cpu via env's cpus, so now, env's cpus is a candidate not
only for src_cpus, but also dst_cpus.

With this patch, we can remove lb_iterations and
max_lb_iterations, because we decide whether we can go ahead or
not via env's cpus.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Tested-by: Jason Low <jason.low2@hp.com>
Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Cc: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1366705662-3587-7-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-24 08:52:46 +02:00
Joonsoo Kim
e6252c3ef4 sched: Rename load_balance_tmpmask to load_balance_mask
This name doesn't represent specific meaning.
So rename it to imply it's purpose.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Tested-by: Jason Low <jason.low2@hp.com>
Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Cc: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1366705662-3587-6-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-24 08:52:45 +02:00
Joonsoo Kim
d31980846f sched: Move up affinity check to mitigate useless redoing overhead
Currently, LBF_ALL_PINNED is cleared after affinity check is
passed. So, if task migration is skipped by small load value or
small imbalance value in move_tasks(), we don't clear
LBF_ALL_PINNED. At last, we trigger 'redo' in load_balance().

Imbalance value is often so small that any tasks cannot be moved
to other cpus and, of course, this situation may be continued
after we change the target cpu. So this patch move up affinity
check code and clear LBF_ALL_PINNED before evaluating load value
in order to mitigate useless redoing overhead.

In addition, re-order some comments correctly.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Tested-by: Jason Low <jason.low2@hp.com>
Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Cc: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1366705662-3587-5-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-24 08:52:44 +02:00
Joonsoo Kim
cfc0311804 sched: Don't consider other cpus in our group in case of NEWLY_IDLE
Commit 88b8dac0 makes load_balance() consider other cpus in its
group, regardless of idle type. When we do NEWLY_IDLE balancing,
we should not consider it, because a motivation of NEWLY_IDLE
balancing is to turn this cpu to non idle state if needed. This
is not the case of other cpus. So, change code not to consider
other cpus for NEWLY_IDLE balancing.

With this patch, assign 'if (pulled_task) this_rq->idle_stamp =
0' in idle_balance() is corrected, because NEWLY_IDLE balancing
doesn't consider other cpus. Assigning to 'this_rq->idle_stamp'
is now valid.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Tested-by: Jason Low <jason.low2@hp.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Cc: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1366705662-3587-4-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-24 08:52:44 +02:00
Joonsoo Kim
de5eb2dd7f sched: Explicitly cpu_idle_type checking in rebalance_domains()
After commit 88b8dac0, dst-cpu can be changed in load_balance(),
then we can't know cpu_idle_type of dst-cpu when load_balance()
return positive. So, add explicit cpu_idle_type checking.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Tested-by: Jason Low <jason.low2@hp.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Cc: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1366705662-3587-3-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-24 08:52:43 +02:00
Joonsoo Kim
f1cd085810 sched: Change position of resched_cpu() in load_balance()
cur_ld_moved is reset if env.flags hit LBF_NEED_BREAK.
So, there is possibility that we miss doing resched_cpu().
Correct it as changing position of resched_cpu()
before checking LBF_NEED_BREAK.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Tested-by: Jason Low <jason.low2@hp.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Cc: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1366705662-3587-2-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-24 08:52:43 +02:00
David S. Miller
6e0895c2ea Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/ethernet/emulex/benet/be_main.c
	drivers/net/ethernet/intel/igb/igb_main.c
	drivers/net/wireless/brcm80211/brcmsmac/mac80211_if.c
	include/net/scm.h
	net/batman-adv/routing.c
	net/ipv4/tcp_input.c

The e{uid,gid} --> {uid,gid} credentials fix conflicted with the
cleanup in net-next to now pass cred structs around.

The be2net driver had a bug fix in 'net' that overlapped with the VLAN
interface changes by Patrick McHardy in net-next.

An IGB conflict existed because in 'net' the build_skb() support was
reverted, and in 'net-next' there was a comment style fix within that
code.

Several batman-adv conflicts were resolved by making sure that all
calls to batadv_is_my_mac() are changed to have a new bat_priv first
argument.

Eric Dumazet's TS ECR fix in TCP in 'net' conflicted with the F-RTO
rewrite in 'net-next', mostly overlapping changes.

Thanks to Stephen Rothwell and Antonio Quartulli for help with several
of these merge resolutions.

Signed-off-by: David S. Miller <davem@davemloft.net>
2013-04-22 20:32:51 -04:00
Frederic Weisbecker
cb41a29076 nohz: Add basic tracing
It's not obvious to find out why the full dynticks subsystem
doesn't always stop the tick: whether this is due to kthreads,
posix timers, perf events, etc...

These new tracepoints are here to help the user diagnose
the failures and test this feature.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-22 23:03:09 +02:00
Frederic Weisbecker
0637e02939 nohz: Select wide RCU nocb for full dynticks
It makes testing and implementation much easier as we
know in advance that all CPUs are RCU nocbs.

Also this prepares to remove the dynamic check for
nohz_full= boot mask to be a subset of rcu_nocbs=

Eventually this should also help removing the requirement
for the boot CPU to be outside the full dynticks range.

Suggested-by: Christoph Lameter <cl@linux.com>
Suggested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-22 23:02:26 +02:00
Frederic Weisbecker
67826eae8c nohz: Disable the tick when irq resume in full dynticks CPU
Eventually try to disable tick on irq exit, now that the
fundamental infrastructure is in place.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-22 20:29:09 +02:00
Frederic Weisbecker
99e5ada940 nohz: Re-evaluate the tick for the new task after a context switch
When a task is scheduled in, it may have some properties
of its own that could make the CPU reconsider the need for
the tick: posix cpu timers, perf events, ...

So notify the full dynticks subsystem when a task gets
scheduled in and re-check the tick dependency at this
stage. This is done through a self IPI to avoid messing
up with any current lock scenario.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-22 20:29:07 +02:00
Frederic Weisbecker
5811d9963e nohz: Prepare to stop the tick on irq exit
Interrupt exit is a natural place to stop the tick: it happens
after all events happening before and during the irq which
are liable to update the dependency on the tick occured. Also
it makes sure that any check on tick dependency is well ordered
against dynticks kick IPIs.

Bring in the infrastructure that performs the tick dependency
checks on irq exit and shut it down if these checks show that we
can do it safely.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-22 20:29:05 +02:00
Frederic Weisbecker
9014c45d9e nohz: Implement full dynticks kick
Implement the full dynticks kick that is performed from
IPIs sent by various subsystems (scheduler, posix timers, ...)
when they want to notify about a new event that may
reconsider the dependency on the tick.

Most of the time, such an event end up restarting the tick.

(Part of the design with subsystems providing *_can_stop_tick()
helpers suggested by Peter Zijlstra a while ago).

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-22 20:28:04 +02:00
Thomas Gleixner
77c675ba18 timekeeping: Update tk->cycle_last in resume
commit 7ec98e15aa (timekeeping: Delay update of clock->cycle_last)
forgot to update tk->cycle_last in the resume path. This results in a
stale value versus clock->cycle_last and prevents resume in the worst
case.

Reported-by: Jiri Slaby <jslaby@suse.cz>
Reported-and-tested-by: Borislav Petkov <bp@alien8.de>
Acked-by: John Stultz <john.stultz@linaro.org>
Cc: Linux-pm mailing list <linux-pm@lists.linux-foundation.org>
Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1304211648150.21884@ionos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-04-22 20:17:51 +02:00
Frederic Weisbecker
ff442c51f6 nohz: Re-evaluate the tick from the scheduler IPI
The scheduler IPI is used by the scheduler to kick
full dynticks CPUs asynchronously when more than one
task are running or when a new timer list timer is
enqueued. This way the destination CPU can decide
to restart the tick to handle this new situation.

Now let's call that kick in the scheduler IPI.

(Reusing the scheduler IPI rather than implementing
a new IPI was suggested by Peter Zijlstra a while ago)

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-22 20:16:04 +02:00
Frederic Weisbecker
ce831b38ca sched: New helper to prevent from stopping the tick in full dynticks
Provide a new helper to be called from the full dynticks engine
before stopping the tick in order to make sure we don't stop
it when there is more than one task running on the CPU.

This way we make sure that the tick stays alive to maintain
fairness.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-22 20:08:04 +02:00
Frederic Weisbecker
9f3660c2c1 sched: Kick full dynticks CPU that have more than one task enqueued.
Kick the tick on full dynticks CPUs when they get more
than one task running on their queue. This makes sure that
local fairness is maintained by the tick on the destination.

This is done regardless of these tasks' class. We should
be able to be more clever in the future depending on these. eg:
a CPU that runs a SCHED_FIFO task doesn't need to maintain
fairness against local pending tasks of the fair class.

But keep things simple for now.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-22 20:06:54 +02:00
Frederic Weisbecker
026249ef10 perf: New helper to prevent full dynticks CPUs from stopping tick
Provide a new helper that help full dynticks CPUs to prevent
from stopping their tick in case there are events in the local
rotation list.

This way we make sure that perf_event_task_tick() is serviced
on demand.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Stephane Eranian <eranian@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
2013-04-22 19:59:39 +02:00