Commit Graph

15756 Commits

Author SHA1 Message Date
Geert Uytterhoeven
aa848233f7 ntp: Remove unused variable flags in __hardpps
kernel/time/ntp.c: In function ‘__hardpps’:
kernel/time/ntp.c:877: warning: unused variable ‘flags’

commit a076b2146f ("ntp: Remove ntp_lock,
using the timekeeping locks to protect ntp state") removed its users,
but not the actual variable.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2013-05-28 13:45:19 -07:00
Linus Torvalds
8f05bde9bd Merge tag 'kmemleak-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux-aarch64
Pull kmemleak patches from Catalin Marinas:
 "Kmemleak now scans all the writable and non-executable module sections
  to avoid false positives (previously it was only scanning specific
  sections and missing .ref.data)."

* tag 'kmemleak-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux-aarch64:
  kmemleak: No need for scanning specific module sections
  kmemleak: Scan all allocated, writeable and not executable module sections
2013-05-18 10:21:32 -07:00
Steven Rostedt
89c837351d kmemleak: No need for scanning specific module sections
As kmemleak now scans all module sections that are allocated, writable
and non executable, there's no need to scan individual sections that
might reference data.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
2013-05-17 09:53:36 +01:00
Steven Rostedt
06c9494c0e kmemleak: Scan all allocated, writeable and not executable module sections
Instead of just picking data sections by name (names that start
with .data, .bss or .ref.data), use the section flags and scan all
sections that are allocated, writable and not executable. Which should
cover all sections of a module that might reference data.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
[catalin.marinas@arm.com: removed unused 'name' variable]
[catalin.marinas@arm.com: collapsed 'if' blocks]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
2013-05-17 09:53:07 +01:00
Linus Torvalds
4a007ed926 Merge branch 'for-3.10-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue fixes from Tejun Heo:
 "Three more workqueue regression fixes.

   - Fix unbalanced unlock in trylock failure path of manage_workers().
     This shouldn't happen often in the wild but is possible.

   - While making schedule_work() and friends inline, they become
     unavailable to !GPL modules.  Allow !GPL modules to access basic
     stuff - system_wq and queue_*work_on() - so that schedule_work()
     and friends can be used.

   - During boot, the unbound NUMA support code allocates a cpumask for
     each possible node using alloc_cpumask_var_node(), which ends up
     trying to allocate node-specific memory even for offline nodes
     triggering BUG in the memory alloc code.  Use NUMA_NO_NODE for
     offline nodes."

* 'for-3.10-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: don't perform NUMA-aware allocations on offline nodes in wq_numa_init()
  workqueue: Make schedule_work() available again to non GPL modules
  workqueue: correct handling of the pool spin_lock
2013-05-16 12:03:28 -07:00
Linus Torvalds
ff89acc563 Merge branch 'rcu/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu
Pull RCU fixes from Paul McKenney:
 "A couple of fixes for RCU regressions:

   - A boneheaded boolean-logic bug that resulted in excessive delays on
     boot, hibernation and suspend that was reported by Borislav Petkov,
     Bjørn Mork, and Joerg Roedel.  The fix inserts a single "!".

   - A fix for a boot-time splat due to allocating from bootmem too late
     in boot, fix courtesy of Sasha Levin with additional help from
     Yinghai Lu."

* 'rcu/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu:
  rcu: Don't allocate bootmem from rcu_init()
  rcu: Fix comparison sense in rcu_needs_cpu()
2013-05-16 12:02:07 -07:00
Oleg Nesterov
264b83c07a usermodehelper: check subprocess_info->path != NULL
argv_split(empty_or_all_spaces) happily succeeds, it simply returns
argc == 0 and argv[0] == NULL. Change call_usermodehelper_exec() to
check sub_info->path != NULL to avoid the crash.

This is the minimal fix, todo:

 - perhaps we should change argv_split() to return NULL or change the
   callers.

 - kill or justify ->path[0] check

 - narrow the scope of helper_lock()

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-By: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-05-16 12:01:11 -07:00
Tejun Heo
1be0c25da5 workqueue: don't perform NUMA-aware allocations on offline nodes in wq_numa_init()
wq_numa_init() builds per-node cpumasks which are later used to make
unbound workqueues NUMA-aware.  The cpumasks are allocated using
alloc_cpumask_var_node() for all possible nodes.  Unfortunately, on
machines with off-line nodes, this leads to NUMA-aware allocations on
existing bug offline nodes, which in turn triggers BUG in the memory
allocation code.

Fix it by using NUMA_NO_NODE for cpumask allocations for offline
nodes.

  kernel BUG at include/linux/gfp.h:323!
  invalid opcode: 0000 [#1] SMP
  Modules linked in:
  CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.9.0+ #1
  Hardware name: ProLiant BL465c G7, BIOS A19 12/10/2011
  task: ffff880234608000 ti: ffff880234602000 task.ti: ffff880234602000
  RIP: 0010:[<ffffffff8117495d>]  [<ffffffff8117495d>] new_slab+0x2ad/0x340
  RSP: 0000:ffff880234603bf8  EFLAGS: 00010246
  RAX: 0000000000000000 RBX: ffff880237404b40 RCX: 00000000000000d0
  RDX: 0000000000000001 RSI: 0000000000000003 RDI: 00000000002052d0
  RBP: ffff880234603c28 R08: 0000000000000000 R09: 0000000000000001
  R10: 0000000000000001 R11: ffffffff812e3aa8 R12: 0000000000000001
  R13: ffff8802378161c0 R14: 0000000000030027 R15: 00000000000040d0
  FS:  0000000000000000(0000) GS:ffff880237800000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
  CR2: ffff88043fdff000 CR3: 00000000018d5000 CR4: 00000000000007f0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
  Stack:
   ffff880234603c28 0000000000000001 00000000000000d0 ffff8802378161c0
   ffff880237404b40 ffff880237404b40 ffff880234603d28 ffffffff815edba1
   ffff880237816140 0000000000000000 ffff88023740e1c0
  Call Trace:
   [<ffffffff815edba1>] __slab_alloc+0x330/0x4f2
   [<ffffffff81174b25>] kmem_cache_alloc_node_trace+0xa5/0x200
   [<ffffffff812e3aa8>] alloc_cpumask_var_node+0x28/0x90
   [<ffffffff81a0bdb3>] wq_numa_init+0x10d/0x1be
   [<ffffffff81a0bec8>] init_workqueues+0x64/0x341
   [<ffffffff810002ea>] do_one_initcall+0xea/0x1a0
   [<ffffffff819f1f31>] kernel_init_freeable+0xb7/0x1ec
   [<ffffffff815d50de>] kernel_init+0xe/0xf0
   [<ffffffff815ff89c>] ret_from_fork+0x7c/0xb0
  Code: 45  84 ac 00 00 00 f0 41 80 4d 00 40 e9 f6 fe ff ff 66 0f 1f 84 00 00 00 00 00 e8 eb 4b ff ff 49 89 c5 e9 05 fe ff ff <0f> 0b 4c 8b 73 38 44 89 ff 81 cf 00 00 20 00 4c 89 f6 48 c1 ee

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-and-Tested-by: Lingzhu Xiang <lxiang@redhat.com>
2013-05-15 14:24:24 -07:00
Linus Torvalds
c240a539df Merge tag 'trace-fixes-v3.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
 "This includes a fix to a memory leak when adding filters to traces.

  Also, Masami Hiramatsu fixed up some minor bugs that were discovered
  by sparse."

* tag 'trace-fixes-v3.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing/kprobes: Make print_*probe_event static
  tracing/kprobes: Fix a sparse warning for incorrect type in assignment
  tracing/kprobes: Use rcu_dereference_raw for tp->files
  tracing: Fix leaks of filter preds
2013-05-15 14:08:57 -07:00
Linus Torvalds
652df602f8 Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Thomas Gleixner:

 - Fix for a task exit cleanup race caused by a missing a preempt
   disable

 - Cleanup of the event notification functions with a massive reduction
   of duplicated code

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf: Factor out auxiliary events notification
  perf: Fix EXIT event notification
2013-05-15 14:07:02 -07:00
Linus Torvalds
cc51bf6e6d Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Thomas Gleixner:

 - Cure for not using zalloc in the first place, which leads to random
   crashes with CPUMASK_OFF_STACK.

 - Revert a user space visible change which broke udev

 - Add a missing cpu_online early return introduced by the new full
   dyntick conversions

 - Plug a long standing race in the timer wheel cpu hotplug code.
   Sigh...

 - Cleanup NOHZ per cpu data on cpu down to prevent stale data on cpu
   up.

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  time: Revert ALWAYS_USE_PERSISTENT_CLOCK compile time optimizaitons
  timer: Don't reinitialize the cpu base lock during CPU_UP_PREPARE
  tick: Don't invoke tick_nohz_stop_sched_tick() if the cpu is offline
  tick: Cleanup NOHZ per cpu data on cpu down
  tick: Use zalloc_cpumask_var for allocating offstack cpumasks
2013-05-15 14:05:17 -07:00
Linus Torvalds
37cae5e249 Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull core fixes from Thomas Gleixner:

 - Two fixlets for the fallout of the generic idle task conversion

 - Documentation update

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  rcu/idle: Wrap cpu-idle poll mode within rcu_idle_enter/exit
  idle: Fix hlt/nohlt command-line handling in new generic idle
  kthread: Document ways of reducing OS jitter due to per-CPU kthreads
2013-05-15 14:04:00 -07:00
Masami Hiramatsu
b62fdd97fc tracing/kprobes: Make print_*probe_event static
According to sparse warning, print_*probe_event static because
those functions are not directly called from outside.

Link: http://lkml.kernel.org/r/20130513115839.6545.83067.stgit@mhiramat-M0-7522

Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tom Zanussi <tom.zanussi@intel.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-05-15 13:50:24 -04:00
Masami Hiramatsu
3d1fc7b088 tracing/kprobes: Fix a sparse warning for incorrect type in assignment
Fix a sparse warning about the rcu operated pointer is
defined without __rcu address space.

Link: http://lkml.kernel.org/r/20130513115837.6545.23322.stgit@mhiramat-M0-7522

Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tom Zanussi <tom.zanussi@intel.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-05-15 13:50:23 -04:00
Masami Hiramatsu
c02c7e65d9 tracing/kprobes: Use rcu_dereference_raw for tp->files
Use rcu_dereference_raw() for accessing tp->files. Because the
write-side uses rcu_assign_pointer() for memory barrier,
the read-side also has to use rcu_dereference_raw() with
read memory barrier.

Link: http://lkml.kernel.org/r/20130513115834.6545.17022.stgit@mhiramat-M0-7522

Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tom Zanussi <tom.zanussi@intel.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-05-15 13:50:22 -04:00
Steven Rostedt (Red Hat)
60705c8946 tracing: Fix leaks of filter preds
Special preds are created when folding a series of preds that
can be done in serial. These are allocated in an ops field of
the pred structure. But they were never freed, causing memory
leaks.

This was discovered using the kmemleak checker:

unreferenced object 0xffff8800797fd5e0 (size 32):
  comm "swapper/0", pid 1, jiffies 4294690605 (age 104.608s)
  hex dump (first 32 bytes):
    00 00 01 00 03 00 05 00 07 00 09 00 0b 00 0d 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff814b52af>] kmemleak_alloc+0x73/0x98
    [<ffffffff8111ff84>] kmemleak_alloc_recursive.constprop.42+0x16/0x18
    [<ffffffff81120e68>] __kmalloc+0xd7/0x125
    [<ffffffff810d47eb>] kcalloc.constprop.24+0x2d/0x2f
    [<ffffffff810d4896>] fold_pred_tree_cb+0xa9/0xf4
    [<ffffffff810d3781>] walk_pred_tree+0x47/0xcc
    [<ffffffff810d5030>] replace_preds.isra.20+0x6f8/0x72f
    [<ffffffff810d50b5>] create_filter+0x4e/0x8b
    [<ffffffff81b1c30d>] ftrace_test_event_filter+0x5a/0x155
    [<ffffffff8100028d>] do_one_initcall+0xa0/0x137
    [<ffffffff81afbedf>] kernel_init_freeable+0x14d/0x1dc
    [<ffffffff814b24b7>] kernel_init+0xe/0xdb
    [<ffffffff814d539c>] ret_from_fork+0x7c/0xb0
    [<ffffffffffffffff>] 0xffffffffffffffff

Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: stable@vger.kernel.org # 2.6.39+
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-05-15 13:49:18 -04:00
Sasha Levin
615ee5443f rcu: Don't allocate bootmem from rcu_init()
When rcu_init() is called we already have slab working, allocating
bootmem at that point results in warnings and an allocation from
slab.  This commit therefore changes alloc_bootmem_cpumask_var() to
alloc_cpumask_var() in rcu_bootup_announce_oddness(), which is called
from rcu_init().

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Tested-by: Robin Holt <holt@sgi.com>

[paulmck: convert to zalloc_cpumask_var(), as suggested by Yinghai Lu.]
2013-05-15 10:41:12 -07:00
John Stultz
b4f711ee03 time: Revert ALWAYS_USE_PERSISTENT_CLOCK compile time optimizaitons
Kay Sievers noted that the ALWAYS_USE_PERSISTENT_CLOCK config,
which enables some minor compile time optimization to avoid
uncessary code in mostly the suspend/resume path could cause
problems for userland.

In particular, the dependency for RTC_HCTOSYS on
!ALWAYS_USE_PERSISTENT_CLOCK, which avoids setting the time
twice and simplifies suspend/resume, has the side effect
of causing the /sys/class/rtc/rtcN/hctosys flag to always be
zero, and this flag is commonly used by udev to setup the
/dev/rtc symlink to /dev/rtcN, which can cause pain for
older applications.

While the udev rules could use some work to be less fragile,
breaking userland should strongly be avoided. Additionally
the compile time optimizations are fairly minor, and the code
being optimized is likely to be reworked in the future, so
lets revert this change.

Reported-by: Kay Sievers <kay@vrfy.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: stable <stable@vger.kernel.org> #3.9
Cc: Feng Tang <feng.tang@intel.com>
Cc: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Link: http://lkml.kernel.org/r/1366828376-18124-1-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-05-14 20:54:06 +02:00
Marc Dionne
ad7b1f841f workqueue: Make schedule_work() available again to non GPL modules
Commit 8425e3d5bd ("workqueue: inline trivial wrappers") changed
schedule_work() and schedule_delayed_work() to inline wrappers,
but these rely on some symbols that are EXPORT_SYMBOL_GPL, while
the original functions were EXPORT_SYMBOL.  This has the effect of
changing the licensing requirement for these functions and making
them unavailable to non GPL modules.

Make them available again by removing the restriction on the
required symbols.

Signed-off-by: Marc Dionne <marc.dionne@your-file-system.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2013-05-14 11:52:51 -07:00
Joonsoo Kim
8f174b1175 workqueue: correct handling of the pool spin_lock
When we fail to mutex_trylock(), we release the pool spin_lock and do
mutex_lock(). After that, we should regrab the pool spin_lock, but,
regrabbing is missed in current code. So correct it.

Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2013-05-14 11:48:15 -07:00
Paul E. McKenney
6faf72834d rcu: Fix comparison sense in rcu_needs_cpu()
Commit c0f4dfd4f (rcu: Make RCU_FAST_NO_HZ take advantage of numbered
callbacks) introduced a bug that can result in excessively long grace
periods.  This bug reverse the senes of the "if" statement checking
for lazy callbacks, so that RCU takes a lazy approach when there are
in fact non-lazy callbacks.  This can result in excessive boot, suspend,
and resume times.

This commit therefore fixes the sense of this "if" statement.

Reported-by: Borislav Petkov <bp@alien8.de>
Reported-by: Bjørn Mork <bjorn@mork.no>
Reported-by: Joerg Roedel <joro@8bytes.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Bjørn Mork <bjorn@mork.no>
Tested-by: Joerg Roedel <joro@8bytes.org>
2013-05-14 10:53:41 -07:00
Linus Torvalds
7fb30d2b60 Merge branch 'for-3.10-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue fix from Tejun Heo:
 "A fix for a workqueue_congested() regression that broke fscache"

* 'for-3.10-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: workqueue_congested() shouldn't translate WORK_CPU_UNBOUND into node number
2013-05-14 09:06:29 -07:00
Tirupathi Reddy
42a5cf46cd timer: Don't reinitialize the cpu base lock during CPU_UP_PREPARE
An inactive timer's base can refer to a offline cpu's base.

In the current code, cpu_base's lock is blindly reinitialized each
time a CPU is brought up. If a CPU is brought online during the period
that another thread is trying to modify an inactive timer on that CPU
with holding its timer base lock, then the lock will be reinitialized
under its feet. This leads to following SPIN_BUG().

<0> BUG: spinlock already unlocked on CPU#3, kworker/u:3/1466
<0> lock: 0xe3ebe000, .magic: dead4ead, .owner: kworker/u:3/1466, .owner_cpu: 1
<4> [<c0013dc4>] (unwind_backtrace+0x0/0x11c) from [<c026e794>] (do_raw_spin_unlock+0x40/0xcc)
<4> [<c026e794>] (do_raw_spin_unlock+0x40/0xcc) from [<c076c160>] (_raw_spin_unlock+0x8/0x30)
<4> [<c076c160>] (_raw_spin_unlock+0x8/0x30) from [<c009b858>] (mod_timer+0x294/0x310)
<4> [<c009b858>] (mod_timer+0x294/0x310) from [<c00a5e04>] (queue_delayed_work_on+0x104/0x120)
<4> [<c00a5e04>] (queue_delayed_work_on+0x104/0x120) from [<c04eae00>] (sdhci_msm_bus_voting+0x88/0x9c)
<4> [<c04eae00>] (sdhci_msm_bus_voting+0x88/0x9c) from [<c04d8780>] (sdhci_disable+0x40/0x48)
<4> [<c04d8780>] (sdhci_disable+0x40/0x48) from [<c04bf300>] (mmc_release_host+0x4c/0xb0)
<4> [<c04bf300>] (mmc_release_host+0x4c/0xb0) from [<c04c7aac>] (mmc_sd_detect+0x90/0xfc)
<4> [<c04c7aac>] (mmc_sd_detect+0x90/0xfc) from [<c04c2504>] (mmc_rescan+0x7c/0x2c4)
<4> [<c04c2504>] (mmc_rescan+0x7c/0x2c4) from [<c00a6a7c>] (process_one_work+0x27c/0x484)
<4> [<c00a6a7c>] (process_one_work+0x27c/0x484) from [<c00a6e94>] (worker_thread+0x210/0x3b0)
<4> [<c00a6e94>] (worker_thread+0x210/0x3b0) from [<c00aad9c>] (kthread+0x80/0x8c)
<4> [<c00aad9c>] (kthread+0x80/0x8c) from [<c000ea80>] (kernel_thread_exit+0x0/0x8)

As an example, this particular crash occurred when CPU #3 is executing
mod_timer() on an inactive timer whose base is refered to offlined CPU
#2.  The code locked the timer_base corresponding to CPU #2. Before it
could proceed, CPU #2 came online and reinitialized the spinlock
corresponding to its base. Thus now CPU #3 held a lock which was
reinitialized. When CPU #3 finally ended up unlocking the old cpu_base
corresponding to CPU #2, we hit the above SPIN_BUG().

CPU #0		CPU #3				       CPU #2
------		-------				       -------
.....		 ......				      <Offline>
		mod_timer()
		 lock_timer_base
		   spin_lock_irqsave(&base->lock)

cpu_up(2)	 .....				        ......
							init_timers_cpu()
....		 .....				    	spin_lock_init(&base->lock)
.....		   spin_unlock_irqrestore(&base->lock)  ......
		   <spin_bug>

Allocation of per_cpu timer vector bases is done only once under
"tvec_base_done[]" check. In the current code, spinlock_initialization
of base->lock isn't under this check. When a CPU is up each time the
base lock is reinitialized. Move base spinlock initialization under
the check.

Signed-off-by: Tirupathi Reddy <tirupath@codeaurora.org>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1368520142-4136-1-git-send-email-tirupath@codeaurora.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-05-14 17:59:18 +02:00
Srivatsa S. Bhat
b47430d3ad rcu/idle: Wrap cpu-idle poll mode within rcu_idle_enter/exit
Bjørn Mork reported the following warning when running powertop.

[   49.289034] ------------[ cut here ]------------
[   49.289055] WARNING: at kernel/rcutree.c:502 rcu_eqs_exit_common.isra.48+0x3d/0x125()
[   49.289244] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.10.0-bisect-rcu-warn+ #107
[   49.289251]  ffffffff8157d8c8 ffffffff81801e28 ffffffff8137e4e3 ffffffff81801e68
[   49.289260]  ffffffff8103094f ffffffff81801e68 0000000000000000 ffff88023afcd9b0
[   49.289268]  0000000000000000 0140000000000000 ffff88023bee7700 ffffffff81801e78
[   49.289276] Call Trace:
[   49.289285]  [<ffffffff8137e4e3>] dump_stack+0x19/0x1b
[   49.289293]  [<ffffffff8103094f>] warn_slowpath_common+0x62/0x7b
[   49.289300]  [<ffffffff8103097d>] warn_slowpath_null+0x15/0x17
[   49.289306]  [<ffffffff810a9006>] rcu_eqs_exit_common.isra.48+0x3d/0x125
[   49.289314]  [<ffffffff81079b49>] ? trace_hardirqs_off_caller+0x37/0xa6
[   49.289320]  [<ffffffff810a9692>] rcu_idle_exit+0x85/0xa8
[   49.289327]  [<ffffffff8107076e>] trace_cpu_idle_rcuidle+0xae/0xff
[   49.289334]  [<ffffffff810708b1>] cpu_startup_entry+0x72/0x115
[   49.289341]  [<ffffffff813689e5>] rest_init+0x149/0x150
[   49.289347]  [<ffffffff8136889c>] ? csum_partial_copy_generic+0x16c/0x16c
[   49.289355]  [<ffffffff81a82d34>] start_kernel+0x3f0/0x3fd
[   49.289362]  [<ffffffff81a8274c>] ? repair_env_string+0x5a/0x5a
[   49.289368]  [<ffffffff81a82481>] x86_64_start_reservations+0x2a/0x2c
[   49.289375]  [<ffffffff81a82550>] x86_64_start_kernel+0xcd/0xd1
[   49.289379] ---[ end trace 07a1cc95e29e9036 ]---

The warning is that 'rdtp->dynticks' has an unexpected value, which roughly
translates to - the calls to rcu_idle_enter() and rcu_idle_exit() were not
made in the correct order, or otherwise messed up.

And Bjørn's painstaking debugging indicated that this happens when the idle
loop enters the poll mode. Looking at the poll function cpu_idle_poll(), and
the implementation of trace_cpu_idle_rcuidle(), the problem becomes very clear:
cpu_idle_poll() lacks calls to rcu_idle_enter/exit(), and trace_cpu_idle_rcuidle()
calls them in the reverse order - first rcu_idle_exit(), and then rcu_idle_enter().
Hence the even/odd alternative sequencing of rdtp->dynticks goes for a toss.

And powertop readily triggers this because powertop uses the idle-tracing
infrastructure extensively.

So, to fix this, wrap the code in cpu_idle_poll() within rcu_idle_enter/exit(),
so that it blends properly with the calls inside trace_cpu_idle_rcuidle() and
thus get the function ordering right.

Reported-and-tested-by: Bjørn Mork <bjorn@mork.no>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/519169BF.4080208@linux.vnet.ibm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-05-14 17:43:29 +02:00
Thomas Gleixner
f7ea0fd639 tick: Don't invoke tick_nohz_stop_sched_tick() if the cpu is offline
commit 5b39939a4 (nohz: Move ts->idle_calls incrementation into strict
idle logic) moved code out of tick_nohz_stop_sched_tick() and missed
to bail out when the cpu is offline. That's causing subsequent
failures as an offline CPU is supposed to die and not to fiddle with
nohz magic.

Return false in can_stop_idle_tick() if the cpu is offline.

Reported-and-tested-by: Jiri Kosina <jkosina@suse.cz>
Reported-and-tested-by: Prarit Bhargava <prarit@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1305132138160.2863@ionos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-05-14 17:40:31 +02:00