Bug 552250
| Summary: | Windows virtio block driver performs poorly on small size requests. In addition, cpu usage on the quest side is very high while handling write requests. | ||||||||
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| Product: | Red Hat Enterprise Linux 5 | Reporter: | Vadim Rozenfeld <vrozenfe> | ||||||
| Component: | kvm | Assignee: | Vadim Rozenfeld <vrozenfe> | ||||||
| Status: | CLOSED WONTFIX | QA Contact: | Virtualization Bugs <virt-bugs> | ||||||
| Severity: | medium | Docs Contact: | |||||||
| Priority: | medium | ||||||||
| Version: | 5.5 | CC: | cww, lihuang, llim, tburke, virt-maint, ykaul | ||||||
| Target Milestone: | rc | ||||||||
| Target Release: | --- | ||||||||
| Hardware: | All | ||||||||
| OS: | Linux | ||||||||
| Whiteboard: | |||||||||
| Fixed In Version: | kvm-83-144.el5 | Doc Type: | Bug Fix | ||||||
| Doc Text: | Story Points: | --- | |||||||
| Clone Of: | Environment: | ||||||||
| Last Closed: | 2011-01-17 18:41:58 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: | |||||||||
| Bug Blocks: | 580948 | ||||||||
| Attachments: |
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Description
Vadim Rozenfeld
2010-01-04 13:35:24 UTC
Created attachment 381714 [details]
performance testing results
Here is a private brew build for perf team to test: https://brewweb.devel.redhat.com/getfile?taskID=2171566&name=kvm-83-143.el5.x86_64.rpm Created attachment 382938 [details]
retest result.
Atthched please find the result of *full* test.
finished run test on both kvm-83-140.el5 and kvm-83-144.el5.
test 100% random read and write.
test block size = 512b,1k,2k,4k,8k,16k,32k,64k
test queue depth = 1,2,4,8,16,32,64
the result shows we don't have an evident throughput improvement when write disk. --> Chart 3.5 and Chart 3.6. ( but at least no evident performance regression :) )
the read performance has some enhance ---> Chart 3.1 and Chart 3.3
and the CPU usage has a large improvement, especially on writing. --> Chart 3.6 and Chart 3.8
+++++++++++++++++ Test env ++++++++++++++++++
DELL OPTIPLEX 760.
Intel(R) Core(TM)2 Quad CPU Q9400 @ 2.66GHz
*4 cores
8gb ram
kernel 2.6.18-182.el5
kvm kvm-83-140.el5
kvm-83-144.el5
Guest window 2008 R2.
CLI : /usr/libexec/qemu-kvm -m 2048 -smp 2 -drive file=/root/win2k8-r2-virtio.raw,if=virtio,boot=on,werror=stop -usb -usbdevice tablet -monitor stdio -vnc :1 -net nic,macaddr=00:21:9B:01:02:01,modle=virtio -net tap -rtc-td-hack -uuid c254380c-e301-4564-acf7-3679d4f509a8 -drive file=/root/test.raw,if=virtio -boot c
the virtual disk (test.raw) is on local disk.
raw format.
no other load on guest/host.
+++++++++++++++++ Test env ++++++++++++++++++
In https://brewweb.devel.redhat.com/taskinfo?taskID=2264563 you can find new kvm-83-158.el5.x86_64.rpm with an option to set the queue depth of the physical storage to. So you should add -drive file=,...,x-queue-depth-suppress-notify=STORAGE_QUEUE_DEPTH QE/Perf we need your help with it. Without the flag you get the regular behaviour. x-queue-depth-suppress-notify patch was reverted. The problem wasn't solved, and the status is still "assigned". This request was evaluated by Red Hat Product Management for inclusion in the current release of Red Hat Enterprise Linux. Because the affected component is not scheduled to be updated in the current release, Red Hat is unfortunately unable to address this request at this time. Red Hat invites you to ask your support representative to propose this request, if appropriate and relevant, in the next release of Red Hat Enterprise Linux. This request was erroneously denied for the current release of Red Hat Enterprise Linux. The error has been fixed and this request has been re-proposed for the current release. |