Bug 813227
| Summary: | Balloon value reported doesn't get updated after guest driver is removed and re-inserted. | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 6 | Reporter: | Qunfang Zhang <qzhang> |
| Component: | kernel | Assignee: | Amit Shah <amit.shah> |
| Status: | CLOSED ERRATA | QA Contact: | Virtualization Bugs <virt-bugs> |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | 6.3 | CC: | acathrow, amit.shah, areis, bsarathy, dyasny, juzhang, mazhang, michen, mkenneth, virt-maint, ypu |
| Target Milestone: | rc | ||
| Target Release: | --- | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
| Whiteboard: | |||
| Fixed In Version: | kernel-2.6.32-288.el6 | Doc Type: | Bug Fix |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2013-02-21 06:08:05 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: | |||
|
Description
Qunfang Zhang
2012-04-17 09:27:33 UTC
What does the output of 'free' show within the guest after all these commands? This could be a reporting issue rather than an actual bug in mem resizing. Oh, I just want to update some information related 'free' output:
1. Step 2:
[root@localhost ~]# free -m
total used free shared buffers cached
Mem: 1878 467 1410 0 16 143
-/+ buffers/cache: 308 1570
Swap: 2015 0 2015
2. step 3:
[root@localhost ~]# free -m
total used free shared buffers cached
Mem: 1830 467 1363 0 16 143
-/+ buffers/cache: 307 1523
Swap: 2015 0 2015
2.From step 4-9, "free -m" always show the largest value as setting in the
command line.
That's the same output as when I just boot up guest and do nothing:
[root@localhost ~]# free -m
total used free shared buffers cached
Mem: 1878 467 1410 0 16 143
-/+ buffers/cache: 308 1570
Swap: 2015 0 2015
OK, so this is as expected and the guest behaves normally. If you try 'balloon 2000' as step 10, guest should update with new values. This is a reporting problem, though. No idea why qemu isn't querying the guest as to what the current balloon value is. This is a corner case and the guest behaves correctly, so not critical, deferring to 6.4. Doesn't seem to be a serious issue to me either. Will look into this soon to confirm it. Turns out the kernel doesn't update stats on module removal. Patches posted upstream. This request was evaluated by Red Hat Product Management for inclusion in a Red Hat Enterprise Linux release. Product Management has requested further review of this request by Red Hat Engineering, for potential inclusion in a Red Hat Enterprise Linux release for currently deployed products. This request is not yet committed for inclusion in a release. Patch(es) available on kernel-2.6.32-288.el6 Reproduce this bug on host kernel:2.6.32-279.9.1.el6.x86_64 qemu-kvm:qemu-kvm-0.12.1.2-2.265.el6.x86_64 guest kernel:2.6.32-279.el6.x86_64 Steps to Reproduce: 1. Boot a guest with virtio balloon device. /usr/libexec/qemu-kvm -M rhel6.3.0 -cpu host -enable-kvm -m 2G -smp 2,sockets=1,cores=2,threads=1 -name rhel6.3 -uuid 4c84db67-faf8-4498-9829-19a3d6431d9d -rtc base=localtime,driftfix=slew -boot c -spice port=5930,disable-ticketing -vga qxl -global qxl-vga.vram_size=33554432 -qmp tcp:0:4444,server,nowait -bios /usr/share/seabios/bios-pm.bin -chardev socket,path=/tmp/qzhang-test-lucky,server,nowait,id=isa1 -device isa-serial,chardev=isa1,id=isa-serial1 -drive file=/root/RHEL-Server-6.3-64-virtio.qcow2,if=none,format=qcow2,id=scsi0 -device virtio-scsi-pci,id=scsi0 -device scsi-disk,bus=scsi0.0,drive=scsi0,scsi-id=0,lun=0 -drive if=none,id=cd -device scsi-cd,drive=cd -usb -device usb-tablet,id=input0 -monitor stdio -device virtio-balloon-pci,id=balloon0,bus=pci.0 2. (qemu) info balloon balloon: actual=2048 3. (qemu) balloon 2000 (qemu)info balloon balloon: actual=2000 4. Inside guest: #rmmod virtio-balloon 5. (qemu)info balloon balloon: actual=2000 6. (qemu) balloon 2048 (qemu)info balloon balloon: actual=2000 7. Inside guest: #modprobe virtio-balloon 8. (qemu)info balloon balloon: actual=2000 9. (qemu) balloon 2048 (qemu) info balloon balloon: actual=2000 Actual results: After step 9, the balloon value is 2000 (M) Expected results: After step 9, the balloon value should be 2048 (M) Verified this bug on host kernel:2.6.32-279.9.1.el6.x86_64 qemu-kvm:qemu-kvm-0.12.1.2-2.265.el6.x86_64 guest kernel:2.6.32-347.el6.x86_64 Steps to Reproduce: 1. Boot a guest with virtio balloon device. /usr/libexec/qemu-kvm -M rhel6.3.0 -cpu host -enable-kvm -m 2G -smp 2,sockets=1,cores=2,threads=1 -name rhel6.3 -uuid 4c84db67-faf8-4498-9829-19a3d6431d9d -rtc base=localtime,driftfix=slew -boot c -spice port=5930,disable-ticketing -vga qxl -global qxl-vga.vram_size=33554432 -qmp tcp:0:4444,server,nowait -bios /usr/share/seabios/bios-pm.bin -chardev socket,path=/tmp/qzhang-test-lucky,server,nowait,id=isa1 -device isa-serial,chardev=isa1,id=isa-serial1 -drive file=/root/RHEL-Server-6.3-64-virtio.qcow2,if=none,format=qcow2,id=scsi0 -device virtio-scsi-pci,id=scsi0 -device scsi-disk,bus=scsi0.0,drive=scsi0,scsi-id=0,lun=0 -drive if=none,id=cd -device scsi-cd,drive=cd -usb -device usb-tablet,id=input0 -monitor stdio -device virtio-balloon-pci,id=balloon0,bus=pci.0 2. (qemu) info balloon balloon: actual=2048 3. (qemu) balloon 2000 (qemu)info balloon balloon: actual=2000 4. Inside guest: #rmmod virtio-balloon 5. (qemu)info balloon balloon: actual=2048 --->the balloon value and enlarge it back to 2048M 6. (qemu) balloon 2048 (qemu)info balloon balloon: actual=2048 7. Inside guest: #modprobe virtio-balloon 8. (qemu)info balloon balloon: actual=2048 9. (qemu) balloon 2048 (qemu) info balloon balloon: actual=2048 Actual results: After step 5 and 9, the balloon value is 2048 (M) guest work well. So this bug has been fixed. According to comment12, set this issue as verified. 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-2013-0496.html |