Bug 1453093
| Summary: | "block-job-set-speed" does not take effect when setting it to 1 first and then a normal value like 100000000 | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 7 | Reporter: | Qianqian Zhu <qizhu> |
| Component: | qemu-kvm-rhev | Assignee: | John Snow <jsnow> |
| Status: | CLOSED ERRATA | QA Contact: | Gu Nini <ngu> |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | 7.4 | CC: | chayang, jen, jsnow, juzhang, knoel, lolyu, mrezanin, virt-maint, xfu |
| Target Milestone: | rc | Keywords: | Regression |
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | qemu-kvm-rhev-2.12.0-1.el7 | Doc Type: | If docs needed, set a value |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2018-11-01 11:01:10 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: | 1473046, 1558351 | ||
The problem is that when speed is set to '1', QEMU transmits a block of data and then realizes it has gone over quota, and so goes to sleep until the average rate/sec would come back under quota, in this case, 20-30 minutes in the future. When setting the new throttle, we don't recalculate this delay. I'll fix upstream, but I don't believe this to be a regression. qemu-kvm-rhev-2.6.0-27.el7.x86_64 has no this issue, so this is a regression. reproduced in block mirror
version info of selected component:
Kernel-3.10.0-709.el7
qemu-kvm-rhev-2.9.0-16.el7_4.6
AMD Opteron(tm) Processor 6344
guest: RHEL7.4
steps:
1. boot up a guest
...
-drive file=/home/test/test.qcow2,format=qcow2,if=none,cache=none,werror=stop,rerror=stop,id=img0 \
-device virtio-blk-pci,bus=pci.0,addr=0x2,drive=img0,id=virtio-disk0,bootindex=1 \
...
2. do block mirror with initial speed set to 100
{ "execute": "drive-mirror", "arguments": { "device": "img0", "target": "/home/test/mirror1.qcow2", "format": "qcow2", "mode": "absolute-paths", "sync": "full", "on-source-error": "stop", "on-target-error": "stop", "speed": 100 } }
3. increase speed to 1000000000
{ "execute": "block-job-set-speed", "arguments": { "device": "img0", "speed": 1000000000} }
4. query block job status
(qemu) info block-jobs
Actual result:
qemu) info block-jobs
Type mirror, device img0: Completed 16842752 of 4562747392 bytes, speed limit 1000000000 bytes/s
(qemu) info block-jobs
Type mirror, device img0: Completed 16842752 of 4562747392 bytes, speed limit 1000000000 bytes/s
(qemu) info block-jobs
Type mirror, device img0: Completed 16842752 of 4562747392 bytes, speed limit 1000000000 bytes/s
(qemu) info block-jobs
Type mirror, device img0: Completed 16842752 of 4562747392 bytes, speed limit 1000000000 bytes/s
...
The offset paused for a certain period.
Due to changes in the way block job sleep is implemented upstream in 2.11, this problem is now pretty easy to fix, so I've posted a patch upstream. [subtext: this fix will require late 2.11-cycle fixes to backport.] https://lists.gnu.org/archive/html/qemu-devel/2017-12/msg01899.html Fixed upstream: aa9ef2e65bed6a8f1709e0523fc856ec08beb657 blockjob: kick jobs on set-speed and amended in https://lists.gnu.org/archive/html/qemu-devel/2018-03/msg03956.html which will be in 2.12. --js Fixed in 2.12 There was indeed a regression upstream that made the mirror job in particular ignore ratelimits. It has been backported in a proposed fix for an otherwise unrelated BZ: https://bugzilla.redhat.com/show_bug.cgi?id=1572856 The patch in question is: https://lists.gnu.org/archive/html/qemu-devel/2018-04/msg03865.html 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. https://access.redhat.com/errata/RHBA-2018:3443 |
Description of problem: Setting speed does not take effect when setting it to 1 first and then a normal value like 100000000 Version-Release number of selected component (if applicable): qemu-kvm-rhev-2.9.0-5.el7.x86_64 kernel-3.10.0-640.el7.x86_64 How reproducible: 100% Steps to Reproduce: 1. Launch guest: /usr/libexec/qemu-kvm -name 'avocado-vt-vm1' \ -vga cirrus \ -device virtio-scsi-pci,id=virtio_scsi_pci0,bus=pci.0,addr=03 \ -drive id=drive_image1,if=none,snapshot=off,aio=native,cache=none,format=raw,file=/home/kvm_autotest_root/images/rhel74-64-virtio-scsi.raw \ -device scsi-hd,id=image1,drive=drive_image1 \ -device virtio-net-pci,mac=9a:ac:ad:ae:af:b0,id=idqKTtyC,vectors=4,netdev=idBAxKKY,bus=pci.0,addr=04 \ -netdev tap,id=idBAxKKY,vhost=on \ -m 4096 \ -smp 4,cores=2,threads=1,sockets=2 \ -cpu 'SandyBridge',+kvm_pv_unhalt \ -vnc :0 \ -rtc base=utc,clock=host,driftfix=slew \ -boot order=cdn,once=c,menu=off,strict=off \ -monitor stdio \ -qmp tcp::5555,server,nowait 2. Live snapshot: { "execute": "blockdev-snapshot-sync", "arguments": { "device": "drive_image1","snapshot-file": "/mnt/iscsi/sn1", "format": "qcow2", "mode": "absolute-paths" } } {"return": {}} { "execute": "blockdev-snapshot-sync", "arguments": { "device": "drive_image1","snapshot-file": "/mnt/iscsi/sn2", "format": "qcow2", "mode": "absolute-paths" } } {"return": {}} { "execute": "blockdev-snapshot-sync", "arguments": { "device": "drive_image1","snapshot-file": "/mnt/iscsi/sn3", "format": "qcow2", "mode": "absolute-paths" } } {"return": {}} 3. Live commit: { "execute": "block-commit", "arguments": { "device": "drive_image1", "base": "/mnt/iscsi/sn1", "top": "/mnt/iscsi/sn3"}} 4. Set speed to 1: { "execute": "block-job-set-speed", "arguments": { "device": "drive_image1","speed":1}} 5. Set speed to 100000000: { "execute": "block-job-set-speed", "arguments": { "device": "drive_image1","speed":100000000}} 6. Query block job: { "execute": "query-block-jobs"} Actual results: Block job stop increasing for more than half hour: { "execute": "query-block-jobs"} {"return": [{"io-status": "ok", "device": "drive_image1", "busy": false, "len": 2188443648, "offset": 578355200, "paused": false, "speed": 100000000, "ready": false, "type": "commit"}]} { "execute": "query-block-jobs"} {"return": [{"io-status": "ok", "device": "drive_image1", "busy": false, "len": 2188443648, "offset": 578355200, "paused": false, "speed": 100000000, "ready": false, "type": "commit"}]} { "execute": "query-block-jobs"} {"return": [{"io-status": "ok", "device": "drive_image1", "busy": false, "len": 2188443648, "offset": 578355200, "paused": false, "speed": 100000000, "ready": false, "type": "commit"}]} { "execute": "query-block-jobs"} {"return": [{"io-status": "ok", "device": "drive_image1", "busy": false, "len": 2188443648, "offset": 578355200, "paused": false, "speed": 100000000, "ready": false, "type": "commit"}]} { "execute": "query-block-jobs"} {"return": [{"io-status": "ok", "device": "drive_image1", "busy": false, "len": 2188443648, "offset": 578355200, "paused": false, "speed": 100000000, "ready": false, "type": "commit"}]} { "execute": "query-block-jobs"} {"return": [{"io-status": "ok", "device": "drive_image1", "busy": false, "len": 2188443648, "offset": 578355200, "paused": false, "speed": 100000000, "ready": false, "type": "commit"}]} { "execute": "query-block-jobs"} {"return": [{"io-status": "ok", "device": "drive_image1", "busy": false, "len": 2188443648, "offset": 578355200, "paused": false, "speed": 100000000, "ready": false, "type": "commit"}]} { "execute": "query-block-jobs"} {"return": [{"io-status": "ok", "device": "drive_image1", "busy": false, "len": 2188443648, "offset": 578355200, "paused": false, "speed": 100000000, "ready": false, "type": "commit"}]} { "execute": "query-block-jobs"} {"return": [{"io-status": "ok", "device": "drive_image1", "busy": false, "len": 2188443648, "offset": 578355200, "paused": false, "speed": 100000000, "ready": false, "type": "commit"}]} Expected results: Block job speed 100000000 takes effect. Additional info: