linux-kernel - Re: perf samples too long without perf running (?!?)

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]

Date:	Sat, 08 Mar 2014 08:51:18 +0100
From:	Mike Galbraith <umgwanakikbuti@...il.com>
To:	Andy Lutomirski <luto@...capital.net>
Cc:	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: perf samples too long without perf running (?!?)

On Fri, 2014-03-07 at 17:57 -0800, Andy Lutomirski wrote: 
> On recent (3.13) kernels, I'm frequently getting messages like:
> 
> perf samples too long (2503 > 2500), lowering
> kernel.perf_event_max_sample_rate to 50000
> 
> a few seconds to minutes after bootup.  As far as I know, I'm not
> using perf.  What's going on here?

14c63f17b1

I get those all the time too, just building kernels.

[  598.583918] perf samples too long (2539 > 2500), lowering kernel.perf_event_max_sample_rate to 50000

Darn nmi_watchdog is an expensive employee.  Scarier are the ones from
2ab00456ea when using perf.  Firing the dog makes it all batter.

-Mike

--
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/