Re: [PATCH] sched: remove extra put_online_cpus() insidesched_setaffinity()

From: Ingo Molnar
Date: Fri Oct 25 2013 - 07:49:06 EST



* Michael wang <wangyun@xxxxxxxxxxxxxxxxxx> wrote:

> commit 6acce3ef84520537f8a09a12c9ddbe814a584dd2
> sched: Remove get_online_cpus() usage
>
> has left one extra put_online_cpus() inside sched_setaffinity(), remove it
> to fix the WARN:
>
> [3165] Watchdog is alive
> [3159] Started watchdog thread 3165
> [ 58.695502] ------------[ cut here ]------------
> [ 58.697835] WARNING: CPU: 0 PID: 3166 at kernel/cpu.c:84 put_online_cpus+0x43/0x70()
> [ 58.702423] Modules linked in:
> [ 58.704404] CPU: 0 PID: 3166 Comm: trinity-child0 Not tainted 3.12.0-rc5-01882-gf3db366 #1172
> [ 58.708530] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
> [ 58.710992] 0000000000000000 ffff88000acfbe50 ffffffff81a24643 0000000000000000
> [ 58.715410] ffff88000acfbe88 ffffffff810c3e6b ffffffff810c3fef 0000000000000000
> [ 58.719826] 0000000000000000 0000000000006ee0 0000000000000ffc ffff88000acfbe98
> [ 58.724348] Call Trace:
> [ 58.726190] [<ffffffff81a24643>] dump_stack+0x4d/0x66
> [ 58.728531] [<ffffffff810c3e6b>] warn_slowpath_common+0x7f/0x98
> [ 58.731069] [<ffffffff810c3fef>] ? put_online_cpus+0x43/0x70
> [ 58.733664] [<ffffffff810c3f32>] warn_slowpath_null+0x1a/0x1c
> [ 58.736258] [<ffffffff810c3fef>] put_online_cpus+0x43/0x70
> [ 58.738686] [<ffffffff810efd59>] sched_setaffinity+0x7d/0x1f9
> [ 58.741210] [<ffffffff810efce1>] ? sched_setaffinity+0x5/0x1f9
> [ 58.743775] [<ffffffff81a2f724>] ? _raw_spin_unlock_irq+0x2c/0x3e
> [ 58.746417] [<ffffffff810c7012>] ? do_setitimer+0x194/0x1f5
> [ 58.748899] [<ffffffff810eff37>] SyS_sched_setaffinity+0x62/0x71
> [ 58.751481] [<ffffffff81a373a9>] system_call_fastpath+0x16/0x1b
> [ 58.754070] ---[ end trace 034818a1f6f06868 ]---
> [ 58.757521] ------------[ cut here ]------------
>
> CC: Ingo Molnar <mingo@xxxxxxxxxx>
> CC: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Reported-by: Fengguang Wu <fengguang.wu@xxxxxxxxx>
> Tested-by: Fengguang Wu <fengguang.wu@xxxxxxxxx>
> Signed-off-by: Michael Wang <wangyun@xxxxxxxxxxxxxxxxxx>
> ---
> kernel/sched/core.c | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
> index c06b8d3..7c61f31 100644
> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -3716,7 +3716,6 @@ long sched_setaffinity(pid_t pid, const struct cpumask *in_mask)
> p = find_process_by_pid(pid);
> if (!p) {
> rcu_read_unlock();
> - put_online_cpus();
> return -ESRCH;
> }

The patch is whitespace damaged.

Thanks,

Ingo
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/