linux-kernel - Re: Perf events warning..

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <1337034048.27020.137.camel@laptop>
Date:	Tue, 15 May 2012 00:20:48 +0200
From:	Peter Zijlstra <a.p.zijlstra@...llo.nl>
To:	Linus Torvalds <torvalds@...ux-foundation.org>
Cc:	Ingo Molnar <mingo@...hat.com>,
	Arnaldo Carvalho de Melo <acme@...stprotocols.net>,
	linux-kernel@...r.kernel.org
Subject: Re: Perf events warning..

On Fri, 2012-05-11 at 08:43 -0700, Linus Torvalds wrote:
> Peter, Ingo, Arnaldo,
>  google doesn't find a warning like this, so it can't be *too*
> commonly reported.
> 
> Anyway, doing some profiling of git "make test" (wonderful load for
> doing lots of small processes that do lots of page faults etc), this
> WARN_ON_ONCE() triggered:
> 
>     ------------[ cut here ]------------
>     WARNING: at kernel/events/core.c:2066 task_ctx_sched_out+0x63/0x70()
>     Hardware name: System Product Name
>     Pid: 18120, comm: git Not tainted 3.4.0-rc6-00089-g4a01c681d58f-dirty #3
>     Call Trace:
>      [<ffffffff810308c5>] warn_slowpath_common+0x75/0xb0
>      [<ffffffff810309c5>] warn_slowpath_null+0x15/0x20
>      [<ffffffff81096d63>] task_ctx_sched_out+0x63/0x70
>      [<ffffffff8109af06>] perf_event_comm+0x1d6/0x2e0
>      [<ffffffff81368ba8>] ? get_random_int+0x88/0xb0
>      [<ffffffff8102e1e2>] ? __mmdrop+0x62/0x90
>      [<ffffffff810e1f93>] set_task_comm+0x63/0x80
>      [<ffffffff810e3206>] setup_new_exec+0x86/0x250
>      [<ffffffff81126b69>] load_elf_binary+0x389/0x1930
>      [<ffffffff81125222>] ? load_misc_binary+0x292/0x390
>      [<ffffffff810bcbdd>] ? get_user_pages+0x4d/0x50
>      [<ffffffff810e13b2>] ? get_arg_page+0xa2/0xd0
>      [<ffffffff810e2b65>] search_binary_handler+0xd5/0x200
>      [<ffffffff811267e0>] ? elf_map+0x170/0x170
>      [<ffffffff810e300d>] do_execve_common.clone.39+0x37d/0x430
>      [<ffffffff810e30d6>] do_execve+0x16/0x20
>      [<ffffffff8100ab75>] sys_execve+0x45/0x70
>      [<ffffffff816b10ac>] stub_execve+0x6c/0xc0
>     ---[ end trace 6fccf3db70f1b560 ]---
> 
> any comments/ideas?

So far I can't make any of the things I came up stick. You ran something
simple like: 'perf record -e cycles:pp -F 20000 make test' ? Or did you
do something more interesting?

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