Crashin programs with recent compcache

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Build kernel 2.6.35-zen2 (without it's ramzswap)
2. Build and install zram revision cb1d3ff91390
3. Load zram with a large disk, swapon it
4. Use "mempig" to eat up memory. http://vi-server.org/vi/bin/mempig.c
5. See the programs crashing.

After attempting to swapoff it crashed even more (even background music stopped 
and it BUGed on every typed key somewhere in TTY code. Only one application and 
switching of consoles remained more-or-less working).

P.S. And I forgot where have I written the revision that is known to work for 
me without any crashes.

Original issue reported on code.google.com by vi0...@gmail.com on 5 Oct 2010 at 10:48

[GoogleCodeExporter]

processor   : 0
vendor_id   : GenuineIntel
cpu family  : 6
model       : 22
model name  : Intel(R) Celeron(R) CPU          530  @ 1.73GHz
stepping    : 1
cpu MHz     : 1728.822
cache size  : 1024 KB
fdiv_bug    : no
hlt_bug     : no
f00f_bug    : no
coma_bug    : no
fpu     : yes
fpu_exception   : yes
cpuid level : 10
wp      : yes
flags       : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat 
pse36 clflush dts acpi mmx fxsr sse sse2 ss tm pbe nx lm constant_tsc 
arch_perfmon pebs bts aperfmperf pni dtes64 monitor ds_cpl tm2 ssse3 cx16 xtpr 
pdcm lahf_lm
bogomips    : 3457.64
clflush size    : 64
cache_alignment : 64
address sizes   : 36 bits physical, 48 bits virtual
power management:

Original comment by vi0...@gmail.com on 5 Oct 2010 at 10:56

Attachments:

• config.gz

[GoogleCodeExporter]

For example, it does not happen (at least not so sereve) at a70e19757bcb.

Original comment by vi0...@gmail.com on 5 Oct 2010 at 11:07

[GoogleCodeExporter]

I have the same problem, I tried the compcache from the kernels 2.6.36-ck5, 
2.6.36-zen1 and the git from zen-sources, the behaviour are the same in all 
these versions, when the zram0 swap started to being used, some programs 
started to crash at random.

There is something I can do to help fix or find where it is the issue? and, 
there is some revision that I can use that does not show the issue?

Thanks!

Original comment by sezd...@gmail.com on 7 Jan 2011 at 9:40

[GoogleCodeExporter]

The code in the repository in now sync'ed with the mainline which has quite 
stable zram implementation.  So, Can you please pull and try again? or try 
2.6.37 kernel directly.

I think this is a dup of Issue 82.

Original comment by nitingupta910@gmail.com on 23 Jan 2011 at 12:02

[GoogleCodeExporter]

OK, trying one that from:

f09409654329b015a2ddbb143e9ef019e241182d "zen: tag zen0: Inanimate Antler" 
2.6.37-zen0

git log -- drivers/staging/zram:

commit 2bd0180e329902237bf8e670313b98fba65f21b6
Author: Jan Steffens <jan.steffens@gmail.com>
Date:   Mon Sep 20 21:27:22 2010 +0200

    Fix zram for 7b6d91d

Will report here about results.

Original comment by vi0...@gmail.com on 23 Jan 2011 at 2:25

[GoogleCodeExporter]

Tested: fails:

http://vi-server.org/vi/_/dmesg_zram.txt

Please tell the exact revision number (of kernel or of compcache) to test.

Original comment by vi0...@gmail.com on 23 Jan 2011 at 2:43

[GoogleCodeExporter]

Testing 9b2f40a12393: no crashes yet.

P.S. notify_free is always 0. Is it the wrong behaviour?

Original comment by vi0...@gmail.com on 24 Jan 2011 at 1:45

[GoogleCodeExporter]

notify mechanism is applicable only when zram is used as swap disk.  When used 
to host a filesystem, it will always remain zero.

Original comment by nitingupta910@gmail.com on 27 Jan 2011 at 3:30

• Changed state: Done