Bug 730686
Summary: | Huge performance regression in NFS client [rhel-5.7.z] | ||||||
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Product: | Red Hat Enterprise Linux 5 | Reporter: | RHEL Program Management <pm-rhel> | ||||
Component: | kernel | Assignee: | Phillip Lougher <plougher> | ||||
Status: | CLOSED ERRATA | QA Contact: | Jian Li <jiali> | ||||
Severity: | high | Docs Contact: | |||||
Priority: | urgent | ||||||
Version: | 5.7 | CC: | admin, aokuliar, bfields, burt, csieh, cww, dhoward, dhowells, djuran, dZhu, hdemonte, iheim, jeder, jentrena, jiali, jlayton, j.s.peatfield, jtluka, jwest, kbooth, kkolakow, nmurray, pasteur, plyons, pm-eus, qcai, rrajaram, rwheeler, sprabhu, steved, vincent | ||||
Target Milestone: | rc | Keywords: | ZStream | ||||
Target Release: | --- | ||||||
Hardware: | x86_64 | ||||||
OS: | Linux | ||||||
Whiteboard: | |||||||
Fixed In Version: | kernel-2.6.18-274.4.1.el5 | Doc Type: | Bug Fix | ||||
Doc Text: |
A previously introduced patch forced the ->flush and ->fsync operations to wait on all WRITE and COMMIT remote procedure calls (RPC) to complete to ensure that those RPCs were completed before returning from fsync() or close(). As a consequence, all WRITEs issued by nfs_flush_list were serialized and caused a performance regression on NFS clients. This update changes nfs_flush_one and nfs_flush_multi to not wait for WRITEs issued when the FLUSH_SYNC parameter is set, resolving performance issues on NFS clients.
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Story Points: | --- | ||||
Clone Of: | Environment: | ||||||
Last Closed: | 2011-10-20 17:31:01 UTC | Type: | --- | ||||
Regression: | --- | Mount Type: | --- | ||||
Documentation: | --- | CRM: | |||||
Verified Versions: | Category: | --- | |||||
oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |||||
Cloudforms Team: | --- | Target Upstream Version: | |||||
Embargoed: | |||||||
Bug Depends On: | 728508 | ||||||
Bug Blocks: | |||||||
Attachments: |
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Description
RHEL Program Management
2011-08-15 11:29:09 UTC
in kernel-2.6.18-274.4.1.el5 linux-2.6-fs-nfs-have-nfs_flush_list-issue-flush_sync-writes-in-parallel.patch This bug is tested in three kernel package, and nfs server use rhel6. Test result is attached, brief info is listed below: kernel-2.6.18-238 "Writer report" "128" "65536" 41923 kernel-2.6.18-274.5.1 "Writer report" "128" "65536" 41594 kernel-2.6.18-274 "Writer report" "128" "65536" 30490 There are many element that effect the result, and the result is steady. Created attachment 526995 [details]
nfs performance test output
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. http://rhn.redhat.com/errata/RHSA-2011-1386.html Technical note added. If any revisions are required, please edit the "Technical Notes" field accordingly. All revisions will be proofread by the Engineering Content Services team. New Contents: A previously introduced patch forced the ->flush and ->fsync operations to wait on all WRITE and COMMIT remote procedure calls (RPC) to complete to ensure that those RPCs were completed before returning from fsync() or close(). As a consequence, all WRITEs issued by nfs_flush_list were serialized and caused a performance regression on NFS clients. This update changes nfs_flush_one and nfs_flush_multi to not wait for WRITEs issued when the FLUSH_SYNC parameter is set, resolving performance issues on NFS clients. |