lkml.org 
[lkml]   [2012]   [Aug]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 0/5] Multiqueue virtio-scsi
On Tue, Aug 28, 2012 at 01:54:12PM +0200, Paolo Bonzini wrote:
> Hi all,
>
> this series adds multiqueue support to the virtio-scsi driver, based
> on Jason Wang's work on virtio-net. It uses a simple queue steering
> algorithm that expects one queue per CPU. LUNs in the same target always
> use the same queue (so that commands are not reordered); queue switching
> occurs when the request being queued is the only one for the target.
> Also based on Jason's patches, the virtqueue affinity is set so that
> each CPU is associated to one virtqueue.

Is there a spec patch? I did not see one.

> I tested the patches with fio, using up to 32 virtio-scsi disks backed
> by tmpfs on the host, and 1 LUN per target.
>
> FIO configuration
> -----------------
> [global]
> rw=read
> bsrange=4k-64k
> ioengine=libaio
> direct=1
> iodepth=4
> loops=20
>
> overall bandwidth (MB/s)
> -----------------
>
> # of targets single-queue multi-queue, 4 VCPUs multi-queue, 8 VCPUs
> 1 540 626 599
> 2 795 965 925
> 4 997 1376 1500
> 8 1136 2130 2060
> 16 1440 2269 2474
> 24 1408 2179 2436
> 32 1515 1978 2319
>
> (These numbers for single-queue are with 4 VCPUs, but the impact of adding
> more VCPUs is very limited).
>
> avg bandwidth per LUN (MB/s)
> ---------------------
>
> # of targets single-queue multi-queue, 4 VCPUs multi-queue, 8 VCPUs
> 1 540 626 599
> 2 397 482 462
> 4 249 344 375
> 8 142 266 257
> 16 90 141 154
> 24 58 90 101
> 32 47 61 72
>
> Testing this may require an irqbalance daemon that is built from git,
> due to http://code.google.com/p/irqbalance/issues/detail?id=37.
> Alternatively you can just set the affinity manually in /proc.
>
> Rusty, can you please give your Acked-by to the first two patches?
>
> Jason Wang (2):
> virtio-ring: move queue_index to vring_virtqueue
> virtio: introduce an API to set affinity for a virtqueue
>
> Paolo Bonzini (3):
> virtio-scsi: allocate target pointers in a separate memory block
> virtio-scsi: pass struct virtio_scsi to virtqueue completion function
> virtio-scsi: introduce multiqueue support
>
> drivers/lguest/lguest_device.c | 1 +
> drivers/remoteproc/remoteproc_virtio.c | 1 +
> drivers/s390/kvm/kvm_virtio.c | 1 +
> drivers/scsi/virtio_scsi.c | 200 ++++++++++++++++++++++++--------
> drivers/virtio/virtio_mmio.c | 11 +-
> drivers/virtio/virtio_pci.c | 58 ++++++++-
> drivers/virtio/virtio_ring.c | 17 +++
> include/linux/virtio.h | 4 +
> include/linux/virtio_config.h | 21 ++++
> 9 files changed, 253 insertions(+), 61 deletions(-)
>
> _______________________________________________
> Virtualization mailing list
> Virtualization@lists.linux-foundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/virtualization


\
 
 \ /
  Last update: 2012-08-30 17:41    [W:0.194 / U:0.492 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site