Messages in this thread | | | Date | Tue, 17 Jun 2014 23:50:57 +0800 | Subject | Re: [RFC PATCH 2/2] block: virtio-blk: support multi virt queues per virtio-blk device | From | Ming Lei <> |
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On Tue, Jun 17, 2014 at 10:40 AM, Stefan Hajnoczi <stefanha@gmail.com> wrote: > On Sat, Jun 14, 2014 at 1:29 AM, Ming Lei <ming.lei@canonical.com> wrote: >> Firstly this patch supports more than one virtual queues for virtio-blk >> device. >> >> Secondly this patch maps the virtual queue to blk-mq's hardware queue. >> >> With this approach, both scalability and performance problem can be improved. >> >> Signed-off-by: Ming Lei <ming.lei@canonical.com> >> --- >> drivers/block/virtio_blk.c | 75 ++++++++++++++++++++++++++++++++------------ >> 1 file changed, 55 insertions(+), 20 deletions(-) >> >> diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c >> index f63d358..e0d077d 100644 >> --- a/drivers/block/virtio_blk.c >> +++ b/drivers/block/virtio_blk.c >> @@ -16,6 +16,8 @@ >> >> #define PART_BITS 4 >> >> +#define MAX_NUM_VQ 16 > > It would be nice to allocate virtqueues dynamically instead of > hardcoding the limit. virtio-scsi also allocates virtqueues > dynamically.
virtio-scsi may have lots of LUN, but virtio-blk only has one disk which needn't lots of hardware queues.
Also it doesn't matter since it isn't part of ABI.
If change on virtio_blk_config is agreed, both host side and guest side can choose to support dynamic length or pre-defined length freely.
Thanks, -- Ming Lei
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