Bug 463470 - Regression: multipath was setting the REQ_FAILFAST flags which caused a performance drop
Summary: Regression: multipath was setting the REQ_FAILFAST flags which caused a perfo...
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Red Hat Enterprise Linux 5
Classification: Red Hat
Component: kernel
Version: 5.3
Hardware: All
OS: Linux
high
high
Target Milestone: beta
: ---
Assignee: Mike Christie
QA Contact: Martin Jenner
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2008-09-23 16:14 UTC by Mike Christie
Modified: 2009-01-20 20:00 UTC (History)
3 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2009-01-20 20:00:58 UTC
Target Upstream Version:
Embargoed:

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Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2009:0225 0 normal SHIPPED_LIVE Important: Red Hat Enterprise Linux 5.3 kernel security and bug fix update 2009-01-20 16:06:24 UTC

Description Mike Christie 2008-09-23 16:14:29 UTC 
Description of problem:

multipath and dm-multipath were setting the REQ_FAILFAST flag instead of the BIO_RW_FAILFAST. REQ_FAILFAST maps to a barrier request, so this results in multipath/dm-mulitpath IO being a lot slower.


Version-Release number of selected component (if applicable):


How reproducible:


Steps to Reproduce:
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Actual results:


Expected results:


Additional info:
Comment 1 RHEL Program Management 2008-09-23 16:45:07 UTC 
This request was evaluated by Red Hat Product Management for inclusion in a Red
Hat Enterprise Linux maintenance release.  Product Management has requested
further review of this request by Red Hat Engineering, for potential
inclusion in a Red Hat Enterprise Linux Update release for currently deployed
products.  This request is not yet committed for inclusion in an Update
release.
Comment 4 Don Zickus 2008-09-30 16:02:00 UTC 
in kernel-2.6.18-117.el5
You can download this test kernel from http://people.redhat.com/dzickus/el5
Comment 7 errata-xmlrpc 2009-01-20 20:00:58 UTC 
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHSA-2009-0225.html
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