Bug 588219
| Summary: | 25% performance regression of concurrent O_DIRECT writes. [rhel-5.5.z] | ||
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| Product: | Red Hat Enterprise Linux 5 | Reporter: | RHEL Program Management <pm-rhel> |
| Component: | kernel | Assignee: | Jiri Pirko <jpirko> |
| Status: | CLOSED ERRATA | QA Contact: | Red Hat Kernel QE team <kernel-qe> |
| Severity: | high | Docs Contact: | |
| Priority: | high | ||
| Version: | 5.5 | CC: | bkahn, dhoward, dshaks, esandeen, jarod, jmoyer, jpirko, kbaxley, kzhang, lmcilroy, myamazak, plyons, pm-eus, rkhan, rwheeler |
| Target Milestone: | rc | Keywords: | Reopened, ZStream |
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | Bug Fix | |
| Doc Text: |
When two or more writes which used the O_DIRECT file access interface were run simultaneously on two separate partitions on the same disk, performance of both writes were reduced. This could have caused a write slowdown of approximately 25% when running two simultaneous "dd oflag=direct" commands on two different partitions. This regression has been fixed in this update so that O_DIRECT write performance does not incur a performance penalty.
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Story Points: | --- |
| Clone Of: | Environment: | ||
| Last Closed: | 2010-07-01 18:29:24 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: | 574285 | ||
| Bug Blocks: | |||
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Description
RHEL Program Management
2010-05-03 07:23:18 UTC
in 2.6.18-194.4.1.el5 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: When two or more writes which used the O_DIRECT file access interface were run simultaneously on two separate partitions on the same disk, performance of both writes were reduced. This could have caused a write slowdown of approximately 25% when running two simultaneous "dd oflag=direct" commands on two different partitions. This regression has been fixed in this update so that O_DIRECT write performance does not incur a performance penalty. 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-2010-0504.html |