Bug 1106420
| Summary: | Enable ioenventfd for virtio-scsi-pci | |||
|---|---|---|---|---|
| Product: | Red Hat Enterprise Linux 6 | Reporter: | Fam Zheng <famz> | |
| Component: | qemu-kvm | Assignee: | Fam Zheng <famz> | |
| Status: | CLOSED ERRATA | QA Contact: | Virtualization Bugs <virt-bugs> | |
| Severity: | urgent | Docs Contact: | ||
| Priority: | urgent | |||
| Version: | 6.6 | CC: | areis, atheurer, bsarathy, chayang, famz, jen, juzhang, lsoft-mso-pj, michen, mkenneth, moshiro, pbonzini, qzhang, rbalakri, sluo, srao, virt-bugs, virt-maint, xigao, yoguma | |
| Target Milestone: | rc | Keywords: | ZStream | |
| Target Release: | --- | |||
| Hardware: | Unspecified | |||
| OS: | Unspecified | |||
| Whiteboard: | ||||
| Fixed In Version: | qemu-kvm-0.12.1.2-2.433.el6 | Doc Type: | Bug Fix | |
| Doc Text: |
This update enables ioeventfd in virtio-scsi-pci. This allows QEMU to process I/O requests outside of the vCPU thread, reducing the latency of submitting requests and improving single task throughput.
|
Story Points: | --- | |
| Clone Of: | ||||
| : | 1123271 (view as bug list) | Environment: | ||
| Last Closed: | 2014-10-14 07:01:34 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: | ||
| Embargoed: | ||||
| Bug Depends On: | ||||
| Bug Blocks: | 893327, 1011600, 1123271 | |||
|
Description
Fam Zheng
2014-06-09 09:58:57 UTC
Yes. I will run it on my system and post the results into this BZ. I have tested the fix on my VMs where I saw similar improvement.
Here is the output from the host which shows the version of qemu-kvm, qemu-img
[root@perf92 ~]# rpm -qa |grep qemu
qemu-img-rhev-0.12.1.2-2.427.el6.test.x86_64
qemu-kvm-rhev-tools-0.12.1.2-2.427.el6.test.x86_64
gpxe-roms-qemu-0.9.7-6.10.el6.noarch
qemu-kvm-rhev-0.12.1.2-2.427.el6.test.x86_64
The data below shows the improvement in the virtio-scsi driver. The comparison shows with increasing queue-depth (1, 16,32, 64) with 4k and 16k block size for Sequential write and Sequential read.
Seq Write
=========
1 16 32 64
4K-before 22690 100041 100689 101356
4K-after 20689 207701 275941 276560
16K-before 76371 376036 366956 382675
16K-after 71765 757915 899679 996745
Seq Read
========
1 16 32 64
4K-before 17988 100208 101883 103654
4K-after 17434 195685 255423 283514
16K-before 63068 393665 394656 391945
16K-after 60595 710237 858082 754236
Fix included in qemu-kvm-0.12.1.2-2.429.el6 *** Bug 1121054 has been marked as a duplicate of this bug. *** Fixed in qemu-kvm-0.12.1.2-2.433.el6 The patch that fixes BZ#1123698 did not reference this BZ, so adding this by hand. Thanks, Jeff! *** Bug 916418 has been marked as a duplicate of 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/RHBA-2014-1490.html |