linux-kernel - perf on 2.6.38-rc4 wedges my box

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-next>] [day] [month] [year] [list]

Message-ID: <x49k4h9az25.fsf@segfault.boston.devel.redhat.com>
Date:	Wed, 09 Feb 2011 12:38:10 -0500
From:	Jeff Moyer <jmoyer@...hat.com>
To:	linux-kernel@...r.kernel.org
Cc:	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Ingo Molnar <mingo@...e.hu>, Paul Mackerras <paulus@...ba.org>,
	Arnaldo Carvalho de Melo <acme@...stprotocols.net>
Subject: perf on 2.6.38-rc4 wedges my box

Hi,

I'm trying out willy's ata_ram driver[1], and in so doing have managed to
wedge my box while using perf record on an aio-stress run:

[root@...allica ~]# modprobe ata_ram capacity=2097152 preallocate=1
[root@...allica ~]# ./aio-stress -O -o 0 -r 4 -d 32 -b 16 /dev/sds
adding stage write
starting with write
file size 1024MB, record size 4KB, depth 32, ios per iteration 8
max io_submit 16, buffer alignment set to 4KB
threads 1 files 1 contexts 1 context offset 2MB verification off
adding file /dev/sds thread 0
write on /dev/sds (621.30 MB/s) 1024.00 MB in 1.65s
thread 0 write totals (621.27 MB/s) 1024.00 MB in 1.65s
[root@...allica ~]# perf record -- ./aio-stress -O -o 0 -r 4 -d 32 -b 16
/dev/sds
adding stage write
starting with write
file size 1024MB, record size 4KB, depth 32, ios per iteration 8
max io_submit 16, buffer alignment set to 4KB
threads 1 files 1 contexts 1 context offset 2MB verification off
adding file /dev/sds thread 0

and there it sits.  On the console, I see:

NOHZ: local_softirq_pending 100
NOHZ: local_softirq_pending 100
NOHZ: local_softirq_pending 100
NOHZ: local_softirq_pending 100
NOHZ: local_softirq_pending 100

The number of messages varies, but this is the most I've seen (it
doesn't keep repeating).  At this point, the machine does not respond to
pings.  As I don't have physical access at the moment, I can't try
alt-sysrq, but might be able to do that tomorrow.  It's probably worth
noting that I've witnessed similar behavior with real devices, so it's
not just the ata_ram driver.

Any ideas on how to track this down?

Thanks!

Jeff

[1] http://git.kernel.org/?p=linux/kernel/git/willy/misc.git;a=shortlog;h=refs/heads/ata-ram
--
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/