| Summary: | Read/Randread/Randrw performance regression | |||
|---|---|---|---|---|
| Product: | Red Hat Enterprise Linux 6 | Reporter: | Xiaomei Gao <xigao> | |
| Component: | qemu-kvm | Assignee: | Fam Zheng <famz> | |
| Status: | CLOSED ERRATA | QA Contact: | Virtualization Bugs <virt-bugs> | |
| Severity: | urgent | Docs Contact: | ||
| Priority: | urgent | |||
| Version: | 6.5 | CC: | areis, bsarathy, famz, juzhang, kwolf, michen, mkenneth, mrezanin, qzhang, rbalakri, stefanha, virt-maint, wquan, xigao | |
| Target Milestone: | rc | Keywords: | Regression, ZStream | |
| Target Release: | --- | |||
| Hardware: | x86_64 | |||
| OS: | Linux | |||
| Whiteboard: | ||||
| Fixed In Version: | qemu-kvm-0.12.1.2-2.417.el6 | Doc Type: | Bug Fix | |
| Doc Text: | Story Points: | --- | ||
| Clone Of: | ||||
| : | 1025138 (view as bug list) | Environment: | ||
| Last Closed: | 2014-10-14 06:53:31 UTC | Type: | Bug | |
| Regression: | --- | Mount Type: | --- | |
| Documentation: | --- | CRM: | ||
| Verified Versions: | Category: | --- | ||
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | ||
| Cloudforms Team: | --- | Target Upstream Version: | ||
| Bug Depends On: | ||||
| Bug Blocks: | 1025138, 1025596 | |||
|
Comment 4
Kevin Wolf
2013-10-25 07:08:23 UTC
(In reply to Kevin Wolf from comment #4) > Can you track the regression down to a specific build or smaller set of > builds? Kevin, commment #0 has mentioned that this regression was introduced by following patch from qemu-kvm-0.12.1.2-2.391.el6. - kvm-block-Produce-zeros-when-protocols-reading-beyond-en.patch [bz#848070] Btw, kvm_exits frequency is much higher compared to old version on virtio_scsi driver in read/randread/randrw category. Besides, we can also see the issue on local format image with virtio_scsi driver in randrw category, but IOPS does not degrades on local raw format image. Through bisect analysis, we found the high kvm_exits frequency on virtio_scsi driver is also introduced by the patch in comment #5 We could see a little performance degradation in randrw category on local format image. Besides, kvm_exits frequency is much higher on virtio_scsi driver in randrw category. Through bisect analysis, they are both introduced by the patch in comment #5, so i changed the title. QE found issues with the fix while testing Bug 1025596 (z-stream clone of this one) and we need additional patches. Moving it back to assigned, Fam is taking care of it. Hi, Fam As we already have bug 1025596 to track the z-stream build, so if I understand correctly, this one is for 6.6 and we should have a rhel6.6 build (like -416) in the "Fixed In Version". :) correct me if I'm wrong. Thanks a lot for your tracking up on this issue so that QE could have a fixed build earlier to test! Qunfang (In reply to Qunfang Zhang from comment #16) > Hi, Fam > > As we already have bug 1025596 to track the z-stream build, so if I > understand correctly, this one is for 6.6 and we should have a rhel6.6 build > (like -416) in the "Fixed In Version". :) correct me if I'm wrong. > > Thanks a lot for your tracking up on this issue so that QE could have a > fixed build earlier to test! > Yes you are right. The status was a mistake. Moving back to POST. Fam 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/RHBA-2014-1490.html |