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| author | Stefan Hajnoczi | 2020-08-18 16:33:47 +0200 |
|---|---|---|
| committer | Michael S. Tsirkin | 2020-08-27 14:29:13 +0200 |
| commit | 9445e1e15e66c19e42bea942ba810db28052cd05 (patch) | |
| tree | 04f90ede63d0f327c660fefbbc45f04c610ec429 /replication.c | |
| parent | virtio-scsi-pci: default num_queues to -smp N (diff) | |
| download | qemu-9445e1e15e66c19e42bea942ba810db28052cd05.tar.gz qemu-9445e1e15e66c19e42bea942ba810db28052cd05.tar.xz qemu-9445e1e15e66c19e42bea942ba810db28052cd05.zip | |
virtio-blk-pci: default num_queues to -smp N
Automatically size the number of virtio-blk-pci request virtqueues to
match the number of vCPUs. Other transports continue to default to 1
request virtqueue.
A 1:1 virtqueue:vCPU mapping ensures that completion interrupts are
handled on the same vCPU that submitted the request. No IPI is
necessary to complete an I/O request and performance is improved. The
maximum number of MSI-X vectors and virtqueues limit are respected.
Performance improves from 78k to 104k IOPS on a 32 vCPU guest with 101
virtio-blk-pci devices (ioengine=libaio, iodepth=1, bs=4k, rw=randread
with NVMe storage).
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Message-Id: <20200818143348.310613-7-stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'replication.c')
0 files changed, 0 insertions, 0 deletions