Bug 726437
| Summary: | Disk write cache flushes are no longer logged in blktrace | ||||||||
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| Product: | Red Hat Enterprise Linux 6 | Reporter: | Jeff Moyer <jmoyer> | ||||||
| Component: | kernel | Assignee: | Jeff Moyer <jmoyer> | ||||||
| Status: | CLOSED ERRATA | QA Contact: | Gris Ge <fge> | ||||||
| Severity: | unspecified | Docs Contact: | |||||||
| Priority: | unspecified | ||||||||
| Version: | 6.2 | CC: | bosun, fge, msnitzer, rwheeler, syeghiay | ||||||
| Target Milestone: | beta | Keywords: | Regression | ||||||
| Target Release: | 6.2 | ||||||||
| Hardware: | Unspecified | ||||||||
| OS: | Unspecified | ||||||||
| Whiteboard: | |||||||||
| Fixed In Version: | kernel-2.6.32-197.el6 | Doc Type: | Bug Fix | ||||||
| Doc Text: | Story Points: | --- | |||||||
| Clone Of: | Environment: | ||||||||
| Last Closed: | 2011-12-06 13:55:06 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: | 736399 | ||||||||
| Bug Blocks: | 743047 | ||||||||
| Attachments: |
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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. Created attachment 515778 [details]
fix up barrier reporting in blktrace
This patch reports 'B' in the blktrace output when the flush flag is set in a request or bio. It also fixes up the translation between blk_add_trace_rq and __blk_add_trace for barrier and discard requests (the latter function checks for BIO_RW_* while the former was setting REQ_*).
Patch(es) available on kernel-2.6.32-197.el6 kernel 197 with blktrace-1.0.1-6.el6 provide write cache flushes: ======== 8,1 0 20713 2.418776737 737 I FWFS 295626 + 2 [jbd2/sda1-8] ======== I am new to FLUSH/FUA, if this is not what we fix in this bug, correct me. Thanks. VERIFY this bug. 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-2011-1530.html |
Created attachment 515749 [details] add BIO_RW_FLUSH to the list of bits to check when flagging barrier requests Description of problem: blktrace will no longer display when write cache flushes are sent to the disk, due to the flush/fua conversion. It was missing a simple conditional in kernel/trace/blktrace.c. Without this information, it will be difficult to diagnose performance issues in the field. Version-Release number of selected component (if applicable): How reproducible: 100% Steps to Reproduce: 1. run a workload that generates fsyncs 2. record blktrace data 3. observe the absense of WBS requests