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| author | Ming Lei <ming.lei@canonical.com> | 2014-07-04 18:04:35 +0800 |
|---|---|---|
| committer | Stefan Hajnoczi <stefanha@redhat.com> | 2014-07-07 11:05:17 +0200 |
| commit | dd67c1d7e75151e2c058ccdd2162643074357442 (patch) | |
| tree | 31e040b1efae71738f98ab05ba4e0236e2aed9d8 /tests/test-string-output-visitor.c | |
| parent | 1b3abdcccf18d98c3952b41be0bc1db3ef6009dd (diff) | |
| download | focaccia-qemu-dd67c1d7e75151e2c058ccdd2162643074357442.tar.gz focaccia-qemu-dd67c1d7e75151e2c058ccdd2162643074357442.zip | |
dataplane: submit I/O as a batch
Before commit 580b6b2aa2(dataplane: use the QEMU block layer for I/O), dataplane for virtio-blk submits block I/O as a batch. This commit 580b6b2aa2 replaces the custom linux AIO implementation(including submit I/O as a batch) with QEMU block layer, but this commit causes ~40% throughput regression on virtio-blk performance, and removing submitting I/O as a batch is one of the causes. This patch applies the newly introduced bdrv_io_plug() and bdrv_io_unplug() interfaces to support submitting I/O at batch for Qemu block layer, and in my test, the change can improve throughput by ~30% with 'aio=native'. Following my fio test script: [global] direct=1 size=4G bsrange=4k-4k timeout=40 numjobs=4 ioengine=libaio iodepth=64 filename=/dev/vdc group_reporting=1 [f] rw=randread Result on one of my small machine(host: x86_64, 2cores, 4thread, guest: 4cores): - qemu master: 65K IOPS - qemu master with these patches: 92K IOPS - 2.0.0 release(dataplane using custom linux aio): 104K IOPS Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'tests/test-string-output-visitor.c')
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