linux-stable.git/kernel/sched.c, branch linux-2.6.34.y Linux kernel stable tree wake_up_process() should be never used to wakeup a TASK_STOPPED/TRACED task 2014-02-10T21:11:05+00:00 Oleg Nesterov oleg@redhat.com 2013-01-21T19:48:17+00:00 e9bf40599d67972c356eb7c024d36ba9093f363c commit 9067ac85d533651b98c2ff903182a20cbb361fcb upstream. wake_up_process() should never wakeup a TASK_STOPPED/TRACED task. Change it to use TASK_NORMAL and add the WARN_ON(). TASK_ALL has no other users, probably can be killed. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [PG: kernel/sched/core.c --> kernel/sched.c on 2.6.34] Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> 
commit 9067ac85d533651b98c2ff903182a20cbb361fcb upstream.

wake_up_process() should never wakeup a TASK_STOPPED/TRACED task.
Change it to use TASK_NORMAL and add the WARN_ON().

TASK_ALL has no other users, probably can be killed.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[PG: kernel/sched/core.c --> kernel/sched.c on 2.6.34]
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
sched: fix divide by zero at {thread_group,task}_times 2013-01-16T21:45:08+00:00 Stanislaw Gruszka sgruszka@redhat.com 2012-08-08T09:27:15+00:00 db379e212d8a9431ae296e80f5ddb597afed4996 commit bea6832cc8c4a0a9a65dd17da6aaa657fe27bc3e upstream. On architectures where cputime_t is 64 bit type, is possible to trigger divide by zero on do_div(temp, (__force u32) total) line, if total is a non zero number but has lower 32 bit's zeroed. Removing casting is not a good solution since some do_div() implementations do cast to u32 internally. This problem can be triggered in practice on very long lived processes: PID: 2331 TASK: ffff880472814b00 CPU: 2 COMMAND: "oraagent.bin" #0 [ffff880472a51b70] machine_kexec at ffffffff8103214b #1 [ffff880472a51bd0] crash_kexec at ffffffff810b91c2 #2 [ffff880472a51ca0] oops_end at ffffffff814f0b00 #3 [ffff880472a51cd0] die at ffffffff8100f26b #4 [ffff880472a51d00] do_trap at ffffffff814f03f4 #5 [ffff880472a51d60] do_divide_error at ffffffff8100cfff #6 [ffff880472a51e00] divide_error at ffffffff8100be7b [exception RIP: thread_group_times+0x56] RIP: ffffffff81056a16 RSP: ffff880472a51eb8 RFLAGS: 00010046 RAX: bc3572c9fe12d194 RBX: ffff880874150800 RCX: 0000000110266fad RDX: 0000000000000000 RSI: ffff880472a51eb8 RDI: 001038ae7d9633dc RBP: ffff880472a51ef8 R8: 00000000b10a3a64 R9: ffff880874150800 R10: 00007fcba27ab680 R11: 0000000000000202 R12: ffff880472a51f08 R13: ffff880472a51f10 R14: 0000000000000000 R15: 0000000000000007 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #7 [ffff880472a51f00] do_sys_times at ffffffff8108845d #8 [ffff880472a51f40] sys_times at ffffffff81088524 #9 [ffff880472a51f80] system_call_fastpath at ffffffff8100b0f2 RIP: 0000003808caac3a RSP: 00007fcba27ab6d8 RFLAGS: 00000202 RAX: 0000000000000064 RBX: ffffffff8100b0f2 RCX: 0000000000000000 RDX: 00007fcba27ab6e0 RSI: 000000000076d58e RDI: 00007fcba27ab6e0 RBP: 00007fcba27ab700 R8: 0000000000000020 R9: 000000000000091b R10: 00007fcba27ab680 R11: 0000000000000202 R12: 00007fff9ca41940 R13: 0000000000000000 R14: 00007fcba27ac9c0 R15: 00007fff9ca41940 ORIG_RAX: 0000000000000064 CS: 0033 SS: 002b Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20120808092714.GA3580@redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [PG: sched/core.c is just sched.c in 2.6.34; also the do_div() on __force u32 isn't explicitly seen since that is in v3.3-rc1~191^2~11] Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> 
commit bea6832cc8c4a0a9a65dd17da6aaa657fe27bc3e upstream.

On architectures where cputime_t is 64 bit type, is possible to trigger
divide by zero on do_div(temp, (__force u32) total) line, if total is a
non zero number but has lower 32 bit's zeroed. Removing casting is not
a good solution since some do_div() implementations do cast to u32
internally.

This problem can be triggered in practice on very long lived processes:

  PID: 2331   TASK: ffff880472814b00  CPU: 2   COMMAND: "oraagent.bin"
   #0 [ffff880472a51b70] machine_kexec at ffffffff8103214b
   #1 [ffff880472a51bd0] crash_kexec at ffffffff810b91c2
   #2 [ffff880472a51ca0] oops_end at ffffffff814f0b00
   #3 [ffff880472a51cd0] die at ffffffff8100f26b
   #4 [ffff880472a51d00] do_trap at ffffffff814f03f4
   #5 [ffff880472a51d60] do_divide_error at ffffffff8100cfff
   #6 [ffff880472a51e00] divide_error at ffffffff8100be7b
      [exception RIP: thread_group_times+0x56]
      RIP: ffffffff81056a16  RSP: ffff880472a51eb8  RFLAGS: 00010046
      RAX: bc3572c9fe12d194  RBX: ffff880874150800  RCX: 0000000110266fad
      RDX: 0000000000000000  RSI: ffff880472a51eb8  RDI: 001038ae7d9633dc
      RBP: ffff880472a51ef8   R8: 00000000b10a3a64   R9: ffff880874150800
      R10: 00007fcba27ab680  R11: 0000000000000202  R12: ffff880472a51f08
      R13: ffff880472a51f10  R14: 0000000000000000  R15: 0000000000000007
      ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
   #7 [ffff880472a51f00] do_sys_times at ffffffff8108845d
   #8 [ffff880472a51f40] sys_times at ffffffff81088524
   #9 [ffff880472a51f80] system_call_fastpath at ffffffff8100b0f2
      RIP: 0000003808caac3a  RSP: 00007fcba27ab6d8  RFLAGS: 00000202
      RAX: 0000000000000064  RBX: ffffffff8100b0f2  RCX: 0000000000000000
      RDX: 00007fcba27ab6e0  RSI: 000000000076d58e  RDI: 00007fcba27ab6e0
      RBP: 00007fcba27ab700   R8: 0000000000000020   R9: 000000000000091b
      R10: 00007fcba27ab680  R11: 0000000000000202  R12: 00007fff9ca41940
      R13: 0000000000000000  R14: 00007fcba27ac9c0  R15: 00007fff9ca41940
      ORIG_RAX: 0000000000000064  CS: 0033  SS: 002b

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20120808092714.GA3580@redhat.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[PG: sched/core.c is just sched.c in 2.6.34; also the do_div() on
 __force u32 isn't explicitly seen since that is in v3.3-rc1~191^2~11]
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
ftrace: Fix memory leak with function graph and cpu hotplug 2011-06-26T16:47:01+00:00 Steven Rostedt srostedt@redhat.com 2011-02-11T02:26:13+00:00 1237d7b76c365f5026e9c55534dcd7126fa014ed commit 868baf07b1a259f5f3803c1dc2777b6c358f83cf upstream. When the fuction graph tracer starts, it needs to make a special stack for each task to save the real return values of the tasks. All running tasks have this stack created, as well as any new tasks. On CPU hot plug, the new idle task will allocate a stack as well when init_idle() is called. The problem is that cpu hotplug does not create a new idle_task. Instead it uses the idle task that existed when the cpu went down. ftrace_graph_init_task() will add a new ret_stack to the task that is given to it. Because a clone will make the task have a stack of its parent it does not check if the task's ret_stack is already NULL or not. When the CPU hotplug code starts a CPU up again, it will allocate a new stack even though one already existed for it. The solution is to treat the idle_task specially. In fact, the function_graph code already does, just not at init_idle(). Instead of using the ftrace_graph_init_task() for the idle task, which that function expects the task to be a clone, have a separate ftrace_graph_init_idle_task(). Also, we will create a per_cpu ret_stack that is used by the idle task. When we call ftrace_graph_init_idle_task() it will check if the idle task's ret_stack is NULL, if it is, then it will assign it the per_cpu ret_stack. Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Suggested-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> 
commit 868baf07b1a259f5f3803c1dc2777b6c358f83cf upstream.

When the fuction graph tracer starts, it needs to make a special
stack for each task to save the real return values of the tasks.
All running tasks have this stack created, as well as any new
tasks.

On CPU hot plug, the new idle task will allocate a stack as well
when init_idle() is called. The problem is that cpu hotplug does
not create a new idle_task. Instead it uses the idle task that
existed when the cpu went down.

ftrace_graph_init_task() will add a new ret_stack to the task
that is given to it. Because a clone will make the task
have a stack of its parent it does not check if the task's
ret_stack is already NULL or not. When the CPU hotplug code
starts a CPU up again, it will allocate a new stack even
though one already existed for it.

The solution is to treat the idle_task specially. In fact, the
function_graph code already does, just not at init_idle().
Instead of using the ftrace_graph_init_task() for the idle task,
which that function expects the task to be a clone, have a
separate ftrace_graph_init_idle_task(). Also, we will create a
per_cpu ret_stack that is used by the idle task. When we call
ftrace_graph_init_idle_task() it will check if the idle task's
ret_stack is NULL, if it is, then it will assign it the per_cpu
ret_stack.

Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Suggested-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
sched: Fix wake_affine() vs RT tasks 2011-06-26T16:46:39+00:00 Peter Zijlstra a.p.zijlstra@chello.nl 2010-05-31T10:37:30+00:00 82f2de71a7b4f618ae8ef44e4ce8052b99115189 commit e51fd5e22e12b39f49b1bb60b37b300b17378a43 upstream. Mike reports that since e9e9250b (sched: Scale down cpu_power due to RT tasks), wake_affine() goes funny on RT tasks due to them still having a !0 weight and wake_affine() still subtracts that from the rq weight. Since nobody should be using se->weight for RT tasks, set the value to zero. Also, since we now use ->cpu_power to normalize rq weights to account for RT cpu usage, add that factor into the imbalance computation. Reported-by: Mike Galbraith <efault@gmx.de> Tested-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1275316109.27810.22969.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> 
commit e51fd5e22e12b39f49b1bb60b37b300b17378a43 upstream.

Mike reports that since e9e9250b (sched: Scale down cpu_power due to RT
tasks), wake_affine() goes funny on RT tasks due to them still having a
!0 weight and wake_affine() still subtracts that from the rq weight.

Since nobody should be using se->weight for RT tasks, set the value to
zero. Also, since we now use ->cpu_power to normalize rq weights to
account for RT cpu usage, add that factor into the imbalance computation.

Reported-by: Mike Galbraith <efault@gmx.de>
Tested-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1275316109.27810.22969.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
sched, cgroup: Fixup broken cgroup movement 2011-06-26T16:46:39+00:00 Peter Zijlstra a.p.zijlstra@chello.nl 2010-10-15T13:24:15+00:00 d4d67e0abb92d7237a2e95dd9106bdc69723ade7 commit b2b5ce022acf5e9f52f7b78c5579994fdde191d4 upstream. Dima noticed that we fail to correct the ->vruntime of sleeping tasks when we move them between cgroups. Reported-by: Dima Zavin <dima@android.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Mike Galbraith <efault@gmx.de> LKML-Reference: <1287150604.29097.1513.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> 
commit b2b5ce022acf5e9f52f7b78c5579994fdde191d4 upstream.

Dima noticed that we fail to correct the ->vruntime of sleeping tasks
when we move them between cgroups.

Reported-by: Dima Zavin <dima@android.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Tested-by: Mike Galbraith <efault@gmx.de>
LKML-Reference: <1287150604.29097.1513.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
sched: fix RCU lockdep splat from task_group() 2011-06-26T16:46:38+00:00 Peter Zijlstra peterz@infradead.org 2010-09-16T15:50:31+00:00 adb7b32eaad2f2ea88ca86864e6095f28bcbea75 commit 6506cf6ce68d78a5470a8360c965dafe8e4b78e3 upstream. This addresses the following RCU lockdep splat: [0.051203] CPU0: AMD QEMU Virtual CPU version 0.12.4 stepping 03 [0.052999] lockdep: fixing up alternatives. [0.054105] [0.054106] =================================================== [0.054999] [ INFO: suspicious rcu_dereference_check() usage. ] [0.054999] --------------------------------------------------- [0.054999] kernel/sched.c:616 invoked rcu_dereference_check() without protection! [0.054999] [0.054999] other info that might help us debug this: [0.054999] [0.054999] [0.054999] rcu_scheduler_active = 1, debug_locks = 1 [0.054999] 3 locks held by swapper/1: [0.054999] #0: (cpu_add_remove_lock){+.+.+.}, at: [<ffffffff814be933>] cpu_up+0x42/0x6a [0.054999] #1: (cpu_hotplug.lock){+.+.+.}, at: [<ffffffff810400d8>] cpu_hotplug_begin+0x2a/0x51 [0.054999] #2: (&rq->lock){-.-...}, at: [<ffffffff814be2f7>] init_idle+0x2f/0x113 [0.054999] [0.054999] stack backtrace: [0.054999] Pid: 1, comm: swapper Not tainted 2.6.35 #1 [0.054999] Call Trace: [0.054999] [<ffffffff81068054>] lockdep_rcu_dereference+0x9b/0xa3 [0.054999] [<ffffffff810325c3>] task_group+0x7b/0x8a [0.054999] [<ffffffff810325e5>] set_task_rq+0x13/0x40 [0.054999] [<ffffffff814be39a>] init_idle+0xd2/0x113 [0.054999] [<ffffffff814be78a>] fork_idle+0xb8/0xc7 [0.054999] [<ffffffff81068717>] ? mark_held_locks+0x4d/0x6b [0.054999] [<ffffffff814bcebd>] do_fork_idle+0x17/0x2b [0.054999] [<ffffffff814bc89b>] native_cpu_up+0x1c1/0x724 [0.054999] [<ffffffff814bcea6>] ? do_fork_idle+0x0/0x2b [0.054999] [<ffffffff814be876>] _cpu_up+0xac/0x127 [0.054999] [<ffffffff814be946>] cpu_up+0x55/0x6a [0.054999] [<ffffffff81ab562a>] kernel_init+0xe1/0x1ff [0.054999] [<ffffffff81003854>] kernel_thread_helper+0x4/0x10 [0.054999] [<ffffffff814c353c>] ? restore_args+0x0/0x30 [0.054999] [<ffffffff81ab5549>] ? kernel_init+0x0/0x1ff [0.054999] [<ffffffff81003850>] ? kernel_thread_helper+0x0/0x10 [0.056074] Booting Node 0, Processors #1lockdep: fixing up alternatives. [0.130045] #2lockdep: fixing up alternatives. [0.203089] #3 Ok. [0.275286] Brought up 4 CPUs [0.276005] Total of 4 processors activated (16017.17 BogoMIPS). The cgroup_subsys_state structures referenced by idle tasks are never freed, because the idle tasks should be part of the root cgroup, which is not removable. The problem is that while we do in-fact hold rq->lock, the newly spawned idle thread's cpu is not yet set to the correct cpu so the lockdep check in task_group(): lockdep_is_held(&task_rq(p)->lock) will fail. But this is a chicken and egg problem. Setting the CPU's runqueue requires that the CPU's runqueue already be set. ;-) So insert an RCU read-side critical section to avoid the complaint. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> 
commit 6506cf6ce68d78a5470a8360c965dafe8e4b78e3 upstream.

This addresses the following RCU lockdep splat:

[0.051203] CPU0: AMD QEMU Virtual CPU version 0.12.4 stepping 03
[0.052999] lockdep: fixing up alternatives.
[0.054105]
[0.054106] ===================================================
[0.054999] [ INFO: suspicious rcu_dereference_check() usage. ]
[0.054999] ---------------------------------------------------
[0.054999] kernel/sched.c:616 invoked rcu_dereference_check() without protection!
[0.054999]
[0.054999] other info that might help us debug this:
[0.054999]
[0.054999]
[0.054999] rcu_scheduler_active = 1, debug_locks = 1
[0.054999] 3 locks held by swapper/1:
[0.054999]  #0:  (cpu_add_remove_lock){+.+.+.}, at: [<ffffffff814be933>] cpu_up+0x42/0x6a
[0.054999]  #1:  (cpu_hotplug.lock){+.+.+.}, at: [<ffffffff810400d8>] cpu_hotplug_begin+0x2a/0x51
[0.054999]  #2:  (&rq->lock){-.-...}, at: [<ffffffff814be2f7>] init_idle+0x2f/0x113
[0.054999]
[0.054999] stack backtrace:
[0.054999] Pid: 1, comm: swapper Not tainted 2.6.35 #1
[0.054999] Call Trace:
[0.054999]  [<ffffffff81068054>] lockdep_rcu_dereference+0x9b/0xa3
[0.054999]  [<ffffffff810325c3>] task_group+0x7b/0x8a
[0.054999]  [<ffffffff810325e5>] set_task_rq+0x13/0x40
[0.054999]  [<ffffffff814be39a>] init_idle+0xd2/0x113
[0.054999]  [<ffffffff814be78a>] fork_idle+0xb8/0xc7
[0.054999]  [<ffffffff81068717>] ? mark_held_locks+0x4d/0x6b
[0.054999]  [<ffffffff814bcebd>] do_fork_idle+0x17/0x2b
[0.054999]  [<ffffffff814bc89b>] native_cpu_up+0x1c1/0x724
[0.054999]  [<ffffffff814bcea6>] ? do_fork_idle+0x0/0x2b
[0.054999]  [<ffffffff814be876>] _cpu_up+0xac/0x127
[0.054999]  [<ffffffff814be946>] cpu_up+0x55/0x6a
[0.054999]  [<ffffffff81ab562a>] kernel_init+0xe1/0x1ff
[0.054999]  [<ffffffff81003854>] kernel_thread_helper+0x4/0x10
[0.054999]  [<ffffffff814c353c>] ? restore_args+0x0/0x30
[0.054999]  [<ffffffff81ab5549>] ? kernel_init+0x0/0x1ff
[0.054999]  [<ffffffff81003850>] ? kernel_thread_helper+0x0/0x10
[0.056074] Booting Node   0, Processors  #1lockdep: fixing up alternatives.
[0.130045]  #2lockdep: fixing up alternatives.
[0.203089]  #3 Ok.
[0.275286] Brought up 4 CPUs
[0.276005] Total of 4 processors activated (16017.17 BogoMIPS).

The cgroup_subsys_state structures referenced by idle tasks are never
freed, because the idle tasks should be part of the root cgroup,
which is not removable.

The problem is that while we do in-fact hold rq->lock, the newly spawned
idle thread's cpu is not yet set to the correct cpu so the lockdep check
in task_group():

  lockdep_is_held(&task_rq(p)->lock)

will fail.

But this is a chicken and egg problem.  Setting the CPU's runqueue requires
that the CPU's runqueue already be set.  ;-)

So insert an RCU read-side critical section to avoid the complaint.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
sched: Move sched_avg_update() to update_cpu_load() 2011-06-26T16:46:38+00:00 Suresh Siddha suresh.b.siddha@intel.com 2010-08-23T20:42:51+00:00 6043c01d813bc3fc21a289461a1a75082516d49b commit da2b71edd8a7db44fe1746261410a981f3e03632 upstream. Currently sched_avg_update() (which updates rt_avg stats in the rq) is getting called from scale_rt_power() (in the load balance context) which doesn't take rq->lock. Fix it by moving the sched_avg_update() to more appropriate update_cpu_load() where the CFS load gets updated as well. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1282596171.2694.3.camel@sbsiddha-MOBL3> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> 
commit da2b71edd8a7db44fe1746261410a981f3e03632 upstream.

Currently sched_avg_update() (which updates rt_avg stats in the rq)
is getting called from scale_rt_power() (in the load balance context)
which doesn't take rq->lock.

Fix it by moving the sched_avg_update() to more appropriate
update_cpu_load() where the CFS load gets updated as well.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1282596171.2694.3.camel@sbsiddha-MOBL3>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
sched: Fix string comparison in /proc/sched_features 2011-01-06T23:08:19+00:00 Mathieu Desnoyers mathieu.desnoyers@efficios.com 2010-09-13T21:47:00+00:00 5978217da51b10453fd4cebc1b8832d07c704c7f commit 7740191cd909b75d75685fb08a5d1f54b8a9d28b upstream. Fix incorrect handling of the following case: INTERACTIVE INTERACTIVE_SOMETHING_ELSE The comparison only checks up to each element's length. Changelog since v1: - Embellish using some Rostedtisms. [ mingo: ^^ == smaller and cleaner ] Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tony Lindgren <tony@atomide.com> LKML-Reference: <20100913214700.GB16118@Krystal> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> 
commit 7740191cd909b75d75685fb08a5d1f54b8a9d28b upstream.

Fix incorrect handling of the following case:

 INTERACTIVE
 INTERACTIVE_SOMETHING_ELSE

The comparison only checks up to each element's length.

Changelog since v1:
 - Embellish using some Rostedtisms.
  [ mingo:                 ^^ == smaller and cleaner ]

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tony Lindgren <tony@atomide.com>
LKML-Reference: <20100913214700.GB16118@Krystal>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
sched: Fix user time incorrectly accounted as system time on 32-bit 2011-01-06T23:07:59+00:00 Stanislaw Gruszka sgruszka@redhat.com 2010-09-14T14:35:14+00:00 a1ec005ae55ca04896388df88a3763903be2bd9c commit e75e863dd5c7d96b91ebbd241da5328fc38a78cc upstream. We have 32-bit variable overflow possibility when multiply in task_times() and thread_group_times() functions. When the overflow happens then the scaled utime value becomes erroneously small and the scaled stime becomes i erroneously big. Reported here: https://bugzilla.redhat.com/show_bug.cgi?id=633037 https://bugzilla.kernel.org/show_bug.cgi?id=16559 Reported-by: Michael Chapman <redhat-bugzilla@very.puzzling.org> Reported-by: Ciriaco Garcia de Celis <sysman@etherpilot.com> Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> LKML-Reference: <20100914143513.GB8415@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> 
commit e75e863dd5c7d96b91ebbd241da5328fc38a78cc upstream.

We have 32-bit variable overflow possibility when multiply in
task_times() and thread_group_times() functions. When the
overflow happens then the scaled utime value becomes erroneously
small and the scaled stime becomes i erroneously big.

Reported here:

 https://bugzilla.redhat.com/show_bug.cgi?id=633037
 https://bugzilla.kernel.org/show_bug.cgi?id=16559

Reported-by: Michael Chapman <redhat-bugzilla@very.puzzling.org>
Reported-by: Ciriaco Garcia de Celis <sysman@etherpilot.com>
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
LKML-Reference: <20100914143513.GB8415@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
sched: Pre-compute cpumask_weight(sched_domain_span(sd)) 2011-01-06T23:07:52+00:00 Peter Zijlstra a.p.zijlstra@chello.nl 2010-04-16T12:59:29+00:00 cabe4242446ba8fdeb806601fa576fece35fc907 commit 669c55e9f99b90e46eaa0f98a67ec53d46dc969a upstream. Dave reported that his large SPARC machines spend lots of time in hweight64(), try and optimize some of those needless cpumask_weight() invocations (esp. with the large offstack cpumasks these are very expensive indeed). Reported-by: David Miller <davem@davemloft.net> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> 
commit 669c55e9f99b90e46eaa0f98a67ec53d46dc969a upstream.

Dave reported that his large SPARC machines spend lots of time in
hweight64(), try and optimize some of those needless cpumask_weight()
invocations (esp. with the large offstack cpumasks these are very
expensive indeed).

Reported-by: David Miller <davem@davemloft.net>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>