From: Peter Zijlstra <peterz@infradead.org>
To: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: raistlin@linux.it, juri.lelli@gmail.com,
Ingo Molnar <mingo@kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [BUG] [ tip/sched/core ] System unresponsive after booting
Date: Thu, 16 Jan 2014 15:17:43 +0100 [thread overview]
Message-ID: <20140116141743.GT31570@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <52D7E343.40909@linaro.org>
On Thu, Jan 16, 2014 at 02:48:51PM +0100, Daniel Lezcano wrote:
> 3570 sched_getparam(3570, { 0 }) = 0
> 3570 sched_getscheduler(3570) = 0 (SCHED_OTHER)
> 3570 sched_get_priority_min(SCHED_OTHER) = 0
> 3570 sched_get_priority_max(SCHED_OTHER) = 0
> 3571 sched_get_priority_min(SCHED_OTHER) = 0
> 3571 sched_get_priority_max(SCHED_OTHER) = 0
> 3571 sched_get_priority_min(SCHED_OTHER) = 0
> 3571 sched_get_priority_max(SCHED_OTHER) = 0
> 3571 sched_setscheduler(3572, SCHED_OTHER, { 0 } <unfinished ...>
> 3571 <... sched_setscheduler resumed> ) = 0
> 3571 sched_get_priority_min(SCHED_OTHER <unfinished ...>
> 3571 <... sched_get_priority_min resumed> ) = 0
> 3571 sched_get_priority_max(SCHED_OTHER <unfinished ...>
> 3571 <... sched_get_priority_max resumed> ) = 0
> 3571 sched_setscheduler(3573, SCHED_OTHER, { 0 } <unfinished ...>
> 3571 <... sched_setscheduler resumed> ) = -1 EPERM (Operation not
> permitted)
> 3571 sched_get_priority_min(SCHED_OTHER <unfinished ...>
> 3571 <... sched_get_priority_min resumed> ) = 0
> 3571 sched_get_priority_max(SCHED_OTHER <unfinished ...>
> 3571 <... sched_get_priority_max resumed> ) = 0
> 3571 sched_setscheduler(3574, SCHED_OTHER, { 0 } <unfinished ...>
> 3571 <... sched_setscheduler resumed> ) = -1 EPERM (Operation not
> permitted)
>
> The same strace but on a kernel which does not hang. The calls to
> sched_setscheduler do not fail.
>
> 3292 sched_getparam(3292, { 0 }) = 0
> 3292 sched_getscheduler(3292) = 0 (SCHED_OTHER)
> 3292 sched_get_priority_min(SCHED_OTHER) = 0
> 3292 sched_get_priority_max(SCHED_OTHER) = 0
> 3293 sched_get_priority_min(SCHED_OTHER) = 0
> 3293 sched_get_priority_max(SCHED_OTHER) = 0
> 3293 sched_get_priority_min(SCHED_OTHER) = 0
> 3293 sched_get_priority_max(SCHED_OTHER) = 0
> 3293 sched_setscheduler(3294, SCHED_OTHER, { 0 } <unfinished ...>
> 3293 <... sched_setscheduler resumed> ) = 0
> 3293 sched_get_priority_min(SCHED_OTHER <unfinished ...>
> 3293 <... sched_get_priority_min resumed> ) = 0
> 3293 sched_get_priority_max(SCHED_OTHER <unfinished ...>
> 3293 <... sched_get_priority_max resumed> ) = 0
> 3293 sched_setscheduler(3295, SCHED_OTHER, { 0 } <unfinished ...>
> 3293 <... sched_setscheduler resumed> ) = 0
> 3293 sched_get_priority_min(SCHED_OTHER <unfinished ...>
> 3293 <... sched_get_priority_min resumed> ) = 0
> 3293 sched_get_priority_max(SCHED_OTHER <unfinished ...>
> 3293 <... sched_get_priority_max resumed> ) = 0
> 3293 sched_setscheduler(3296, SCHED_OTHER, { 0 } <unfinished ...>
> 3293 <... sched_setscheduler resumed> ) = 0
>
> The EPERM error comes from kernel/sched/core.c:3303
>
> ...
> if (fair_policy(policy)) {
> if (!can_nice(p, attr->sched_nice))
> return -EPERM;
> }
> ...
>
>
> But I don't know why this is leading to block a process or making rsyslogd
> being not woken up by a packet coming in the af_unix socket.
Could you test with a fresh tip/master, Ingo just pushed out a stack of
fixes, in particularly:
e3de300d1212b ("sched: Preserve the nice level over sched_setscheduler() and sched_setparam() calls")
39fd8fd22b322 ("sched: Fix up scheduler syscall LTP fails")
Could have affected things.
Meanwhile I'll try and better read what the above says.
Thanks!
next prev parent reply other threads:[~2014-01-16 14:18 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-15 8:27 Daniel Lezcano
2014-01-15 9:22 ` Ingo Molnar
2014-01-15 10:39 ` Peter Zijlstra
2014-01-15 11:00 ` Peter Zijlstra
2014-01-15 14:05 ` Peter Zijlstra
2014-01-15 9:25 ` Michael wang
2014-01-15 11:30 ` Peter Zijlstra
2014-01-15 13:28 ` Daniel Lezcano
2014-01-16 13:40 ` [tip:sched/core] sched: Preserve the nice level over sched_setscheduler() and sched_setparam() calls tip-bot for Peter Zijlstra
2014-01-15 13:27 ` [BUG] [ tip/sched/core ] System unresponsive after booting Daniel Lezcano
2014-01-15 12:04 ` Peter Zijlstra
2014-01-15 12:24 ` Ingo Molnar
2014-01-15 13:45 ` Daniel Lezcano
2014-01-15 13:09 ` Daniel Lezcano
2014-01-16 13:48 ` Daniel Lezcano
2014-01-16 14:17 ` Peter Zijlstra [this message]
2014-01-16 14:20 ` Daniel Lezcano
2014-01-16 14:25 ` Peter Zijlstra
2014-01-16 14:30 ` Daniel Lezcano
2014-01-16 15:42 ` Peter Zijlstra
2014-01-16 15:50 ` Daniel Lezcano
2014-01-16 16:54 ` [PATCH] sched: Fix __sched_setscheduler() nice test Peter Zijlstra
2014-01-16 18:33 ` Peter Zijlstra
2014-01-16 18:39 ` [tip:sched/core] " tip-bot for Peter Zijlstra
2014-01-16 15:28 ` [BUG] [ tip/sched/core ] System unresponsive after booting Daniel Lezcano
2014-01-16 15:48 ` Peter Zijlstra
2014-01-16 15:51 ` Daniel Lezcano
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