Bug 799685 - oom-killer activates when plenty of RAM is still available
Summary: oom-killer activates when plenty of RAM is still available
Keywords:
Status: CLOSED CANTFIX
Alias: None
Product: Fedora
Classification: Fedora
Component: kernel
Version: 15
Hardware: Unspecified
OS: Unspecified
unspecified
unspecified
Target Milestone: ---
Assignee: Kernel Maintainer List
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2012-03-04 09:41 UTC by Slawomir Czarko
Modified: 2012-03-14 14:43 UTC (History)
5 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2012-03-14 14:43:30 UTC
Type: ---
Embargoed:


Attachments (Terms of Use)
Section of /var/log/messages (252.11 KB, application/octet-stream)
2012-03-05 08:52 UTC, Slawomir Czarko
no flags Details
dmesg output (123.66 KB, application/octet-stream)
2012-03-14 12:44 UTC, Slawomir Czarko
no flags Details
/var/log/messages (424.05 KB, application/octet-stream)
2012-03-14 12:44 UTC, Slawomir Czarko
no flags Details

Description Slawomir Czarko 2012-03-04 09:41:31 UTC
Description of problem:

After updating to kernel 2.6.42.7-1.fc15.i686.PAE I'm getting oom-killer activated every few hours. I think this might be related to the bug 745241 or 735946 since I've been using fuse and rsync during that time (regression?).


Version-Release number of selected component (if applicable):
2.6.42.7-1.fc15.i686.PAE

How reproducible:


Steps to Reproduce:
1.
2.
3.
  
Actual results:


Expected results:


Additional info:

Comment 1 Dave Jones 2012-03-05 02:48:47 UTC
we can't do anything with this report without seeing logs from the oomkiller.

Comment 2 Slawomir Czarko 2012-03-05 08:52:10 UTC
Created attachment 567529 [details]
Section of /var/log/messages

This shows what was logged to /var/log/messages when oom-killer activated.

Do you need any other logs?

Comment 3 Slawomir Czarko 2012-03-14 12:43:25 UTC
Just got this again now with 2.6.41.10-3 PAE kernel. Attaching dmesg and /var/log/messages

Comment 4 Slawomir Czarko 2012-03-14 12:44:06 UTC
Created attachment 569971 [details]
dmesg output

Comment 5 Slawomir Czarko 2012-03-14 12:44:36 UTC
Created attachment 569972 [details]
/var/log/messages

Comment 6 Slawomir Czarko 2012-03-14 12:46:34 UTC
Machine has 16 GB RAM and there's a few GB always free (or used by filesystem cache). Swap is either not used or barely (less than 100MB).

Comment 7 Slawomir Czarko 2012-03-14 12:47:25 UTC
Any suggestions on how to debug this?

Comment 8 Slawomir Czarko 2012-03-14 13:13:57 UTC
Is this due to PAE kernel?

Do you think changing value for vm.lowmem_reserve_ratio will help?

Comment 9 Dave Jones 2012-03-14 14:43:30 UTC
the real answer is to move to 64bit. Past 8GB, 32bit gets complicated because of so much low memory being used up by page tables. Once fragmentation starts to happen, this sort of thing is to be expected.

You might have memory free when the oom is triggering, but the problem is that you don't have any of the right 'type' of memory (the gfp mask) free.

You might make it perform a bit better by tweaking syscalls, but you're fundamentally in a losing battle just because you're pushing up against the architectural limits.


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