Bug 689948 - System becomes unresponsive under memory pressure
Summary: System becomes unresponsive under memory pressure
Keywords:
Status: CLOSED INSUFFICIENT_DATA
Alias: None
Product: Red Hat Enterprise Linux 5
Classification: Red Hat
Component: kernel
Version: 5.6
Hardware: Unspecified
OS: Unspecified
urgent
urgent
Target Milestone: rc
: ---
Assignee: Johannes Weiner
QA Contact: Zhouping Liu
URL:
Whiteboard:
Depends On:
Blocks: 743405 807974
TreeView+ depends on / blocked
 
Reported: 2011-03-22 20:39 UTC by Casey Dahlin
Modified: 2018-11-26 19:27 UTC (History)
6 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2012-04-11 17:34:18 UTC
Target Upstream Version:

Attachments (Terms of Use)
Patch to raise bar for synchronous IO in pageout (6.07 KB, application/octet-stream)
2011-03-22 20:39 UTC, Casey Dahlin 		no flags Details
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Description Casey Dahlin 2011-03-22 20:39:52 UTC 
Created attachment 486893 [details]
Patch to raise bar for synchronous IO in pageout

The kernel tends to begin synchronous IO a bit too early in the reclaim path, which can result in lots of IO congestion and severe unresponsiveness. The attached patch makes the kernel a bit less eager to move to synchronous IO when larger allocations are being made, preventing this condition.
Comment 2 RHEL Program Management 2011-06-20 22:37:03 UTC 
This request was evaluated by Red Hat Product Management for inclusion in Red Hat Enterprise Linux 5.7 and Red Hat does not plan to fix this issue the currently developed update.

Contact your manager or support representative in case you need to escalate this bug.
Comment 3 Johannes Weiner 2011-08-10 08:43:36 UTC 
In RHEL5 there is no sync IO from reclaim, that came in with lumpy reclaim for 2.6.24.

Is it possible to get a better description of what's being observed?

What's the value of /proc/sys/vm/dirty_ratio?  And does lowering it to 20 help the workload?
Comment 8 Casey Dahlin 2012-04-11 17:34:18 UTC 
Customer is gone. Haven't heard of this being reproduced anywhere else. Going to go ahead and close.
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