Messages in this thread | | | Date | Mon, 2 Oct 2023 13:50:45 +0200 | Subject | Re: [PATCH v2] virtio_balloon: Fix endless deflation and inflation on arm64 | From | David Hildenbrand <> |
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On 25.09.23 01:58, Gavin Shan wrote: > Hi David and Michael, > > On 8/31/23 11:10, Gavin Shan wrote: >> The deflation request to the target, which isn't unaligned to the >> guest page size causes endless deflation and inflation actions. For >> example, we receive the flooding QMP events for the changes on memory >> balloon's size after a deflation request to the unaligned target is >> sent for the ARM64 guest, where we have 64KB base page size. >> >> /home/gavin/sandbox/qemu.main/build/qemu-system-aarch64 \ >> -accel kvm -machine virt,gic-version=host -cpu host \ >> -smp maxcpus=8,cpus=8,sockets=2,clusters=2,cores=2,threads=1 \ >> -m 1024M,slots=16,maxmem=64G \ >> -object memory-backend-ram,id=mem0,size=512M \ >> -object memory-backend-ram,id=mem1,size=512M \ >> -numa node,nodeid=0,memdev=mem0,cpus=0-3 \ >> -numa node,nodeid=1,memdev=mem1,cpus=4-7 \ >> : \ >> -device virtio-balloon-pci,id=balloon0,bus=pcie.10 >> >> { "execute" : "balloon", "arguments": { "value" : 1073672192 } } >> {"return": {}} >> {"timestamp": {"seconds": 1693272173, "microseconds": 88667}, \ >> "event": "BALLOON_CHANGE", "data": {"actual": 1073610752}} >> {"timestamp": {"seconds": 1693272174, "microseconds": 89704}, \ >> "event": "BALLOON_CHANGE", "data": {"actual": 1073610752}} >> {"timestamp": {"seconds": 1693272175, "microseconds": 90819}, \ >> "event": "BALLOON_CHANGE", "data": {"actual": 1073610752}} >> {"timestamp": {"seconds": 1693272176, "microseconds": 91961}, \ >> "event": "BALLOON_CHANGE", "data": {"actual": 1073610752}} >> {"timestamp": {"seconds": 1693272177, "microseconds": 93040}, \ >> "event": "BALLOON_CHANGE", "data": {"actual": 1073676288}} >> {"timestamp": {"seconds": 1693272178, "microseconds": 94117}, \ >> "event": "BALLOON_CHANGE", "data": {"actual": 1073676288}} >> {"timestamp": {"seconds": 1693272179, "microseconds": 95337}, \ >> "event": "BALLOON_CHANGE", "data": {"actual": 1073610752}} >> {"timestamp": {"seconds": 1693272180, "microseconds": 96615}, \ >> "event": "BALLOON_CHANGE", "data": {"actual": 1073676288}} >> {"timestamp": {"seconds": 1693272181, "microseconds": 97626}, \ >> "event": "BALLOON_CHANGE", "data": {"actual": 1073610752}} >> {"timestamp": {"seconds": 1693272182, "microseconds": 98693}, \ >> "event": "BALLOON_CHANGE", "data": {"actual": 1073676288}} >> {"timestamp": {"seconds": 1693272183, "microseconds": 99698}, \ >> "event": "BALLOON_CHANGE", "data": {"actual": 1073610752}} >> {"timestamp": {"seconds": 1693272184, "microseconds": 100727}, \ >> "event": "BALLOON_CHANGE", "data": {"actual": 1073610752}} >> {"timestamp": {"seconds": 1693272185, "microseconds": 90430}, \ >> "event": "BALLOON_CHANGE", "data": {"actual": 1073610752}} >> {"timestamp": {"seconds": 1693272186, "microseconds": 102999}, \ >> "event": "BALLOON_CHANGE", "data": {"actual": 1073676288}} >> : >> <The similar QMP events repeat> >> >> Fix it by aligning the target up to the guest page size, 64KB in this >> specific case. With this applied, no flooding QMP events are observed >> and the memory balloon's size can be stablizied to 0x3ffe0000 soon >> after the deflation request is sent. >> >> { "execute" : "balloon", "arguments": { "value" : 1073672192 } } >> {"return": {}} >> {"timestamp": {"seconds": 1693273328, "microseconds": 793075}, \ >> "event": "BALLOON_CHANGE", "data": {"actual": 1073610752}} >> { "execute" : "query-balloon" } >> {"return": {"actual": 1073610752}} >> >> Signed-off-by: Gavin Shan <gshan@redhat.com> >> Tested-by: Zhenyu Zhang <zhenyzha@redhat.com> >> --- >> v2: Align @num_pages up to the guest page size in towards_target() >> directly as David suggested. >> --- >> drivers/virtio/virtio_balloon.c | 6 +++++- >> 1 file changed, 5 insertions(+), 1 deletion(-) >> > > If the patch looks good, could you please merge this to Linux 6.6.rc4 since > it's something needed by our downstream. I hope it can land upstream as early > as possible, thanks a lot.
@MST, I cannot spot it in your usual vhost git yet. Should I pick it up or what are your plans?
-- Cheers,
David / dhildenb
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