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Diffstat (limited to 'results/scraper/launchpad-without-comments/1847861')
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diff --git a/results/scraper/launchpad-without-comments/1847861 b/results/scraper/launchpad-without-comments/1847861 new file mode 100644 index 000000000..8f9260a9c --- /dev/null +++ b/results/scraper/launchpad-without-comments/1847861 @@ -0,0 +1,30 @@ +Guest stuttering under high disk IO (virtio) + +Performing io intensive tasks on virtualized Windows causes the system to visually stutter. I can often reproduce the problem by running fio on windows: + +fio --randrepeat=1 --ioengine=windowsaio --direct=1 --gtod_reduce=1 --name=test --filename=\\.\PhysicalDrive0 --bs=4k --iodepth=128 --size=4G --readwrite=randread + +While the fio command is running, moving the mouse pointer will be be laggy. The stuttering does not appear with iodepth <= 32 . The stuttering also manifests while playing games, the music and video pauses for a fraction of second in a playable but disturbing way. + +Here are my system specs: + +Host OS: archlinux +Guest OS: Windows 10 Enterprise +qemu version: qemu-git 8:v4.1.0.r1378.g98b2e3c9ab-1 (from AUR, compiled with -march=native) +CPU: AMD Ryzen Threadripper 1900X 8-Core Processor +Huge Pages: vm.nr_hugepages=4128 +Disk: nvme type=raw, io=threads bus=virtio +GPU (passthrough): Radeon RX 570 + +Here are some fio test results on my windows guest: + +[size=512M,iodepth=1 -> min=30k,avg=31k,stddev=508] +[size=2G,iodepth=8 -> min=203k,avg=207k,stddev=2.3k] +[size=2G,iodepth=16 -> min=320k,avg=330k,stddev=4.3k] +[size=4G,iodepth=32 -> min=300k,avg=310k,stddev=4.8k] +[size=4G,iodepth=64 -> min=278k,avg=366k,stddev=68.6k] -> STUTTER +[size=4G,iodepth=64 -> min=358k,avg=428k,stddev=52.6k] -> STUTTER +[size=4G,iodepth=128 -> min=92k,avg=217k,stddev=185k] -> STUTTER +[size=4G,iodepth=128 -> min=241k,avg=257k,stddev=14k] -> same config as above, but no stuttering + +The min and avg values are the bandwidth values reported in KB/s by fio. You can see that, when the stuttering occurs, the stardard deviation is high and the minimum bandwidth is way below the average. \ No newline at end of file |