System crash with swap on a zram device on a 32 bits system with kernel >= 3.6

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I have 2 zram swap partitions of 64 MB each (along with other swap devices on a 
hard drive).

gentoo ~ # swapon -s
Filename     Type            Size    Used    Priority
/dev/sda8    partition       7325604 99100   -1
/dev/sda10   partition       2934376 98912   -2
/dev/zram0   partition       65532   65492   16383
/dev/zram1   partition       65532   65492   16383

When I run some apps that need a lot of memory I get a system crash. Managed to 
recover the call trace from /var/log/messages (attached).

I'm using Gentoo - 32 bits, kernel 3.7.1. Got this issue with every kernel in 
the 3.6 series that I've tried - 3.6.2 and 3.6.6. Didn't try 3.6.8 because the 
code under drivers/staging/zram was the same as in 3.6.2. Only tried 3.7.1 
(that has the same code as before) to get this backtrace and report it.

The hardware is an Intel(R) Pentium(R) 4 CPU 3.00GHz (32 bit) with 1 GB of RAM. 
I must say I'm using similar setups on other 2 *64 bits* machines without any 
issues (various kernels from 3.6 to 3.7.1).

Original issue reported on code.google.com by andrei.m...@gmail.com on 23 Dec 2012 at 5:40

Attachments:

• zram-bug-log.txt

[GoogleCodeExporter]

Looks like you are hitting the same issue as this:
https://bugzilla.kernel.org/show_bug.cgi?id=50081

Please try the patch attached in comment #11 there.

Original comment by nitingupta910@gmail.com on 23 Dec 2012 at 6:48

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Yes, it seems to be that issue and the patch fixed it. I was not able to 
reproduce the crash by using memory hungry apps or an in-memory block device. 
All good then, thank you!
Also confirmed this on the kernel bugzilla 
https://bugzilla.kernel.org/show_bug.cgi?id=50081#c15 .

Original comment by andrei.m...@gmail.com on 23 Dec 2012 at 9:03

[GoogleCodeExporter]

Original comment by nitingupta910@gmail.com on 23 Dec 2012 at 10:14

• Changed state: Fixed