linux-kernel - Debugging system freezes on filesystem writes

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]

Date:	Mon, 29 Oct 2012 00:39:46 +0200
From:	Marcus Sundman <marcus@...ox.fi>
To:	linux-kernel@...r.kernel.org
Subject: Debugging system freezes on filesystem writes

Hi,

I have a big problem with the system freezing and would appreciate any 
help on debugging this and pinpointing where exactly the problem is, so 
it could be fixed.

So, whenever I write to the disk the system comes to a crawl or freezes 
altogether. This happens even when the writing processes are running on 
nice '19' and ionice 'idle'. (E.g. a 10 second compile could freeze the 
system for several minutes, rendering the computer pretty much unusable 
for anything interesting.)

Here you can see a 20 second gap even in superhigh priority:
# nice -n -20 ionice -c1 iostat -t -m -d -x 1 > http://pastebin.com/j5qnh2VV

I'm currently running 3.5.0-17-lowlatency on the ZenBook UX31E, using 
the NOOP I/O scheduler on the SanDisk SSD U100. The chipset seems to be 
Intel QS67. I've had this same problem on 3.2.0 generic and lowlatency 
kernels.

The syslog says nothing relevant before/during/after these freezes.

Any ideas on finding the culprit?

Regards,
Marcus

--
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/