The virtio-blk device will soon be able to assign virtqueues to IOThreads,
eliminating the single IOThread bottleneck. In order to do that, the I/O code
path must support running in multiple threads.

This patch series removes the AioContext lock from the virtio-blk I/O code
path, adds thread-safety where it is required, and ensures that Linux AIO and
io_uring are available regardless of which thread calls into the block driver.
With these changes virtio-blk is ready for the iothread-vq-mapping feature,
which will be introduced in the next patch series.

Based-on: 20230913200045.1024233-1-stefanha@redhat.com ("[PATCH v3 0/4] virtio-blk: use blk_io_plug_call() instead of notification BH")
Based-on: 20230912231037.826804-1-stefanha@redhat.com ("[PATCH v3 0/5] block-backend: process I/O in the current AioContext")

Stefan Hajnoczi (4):
  block/file-posix: set up Linux AIO and io_uring in the current thread
  virtio-blk: add lock to protect s->rq
  virtio-blk: don't lock AioContext in the completion code path
  virtio-blk: don't lock AioContext in the submission code path

 include/hw/virtio/virtio-blk.h |   3 +-
 block/file-posix.c             |  99 +++++++++++++++---------------
 hw/block/virtio-blk.c          | 106 +++++++++++++++------------------
 3 files changed, 98 insertions(+), 110 deletions(-)

-- 
2.41.0

Am 14.09.2023 um 16:00 hat Stefan Hajnoczi geschrieben:
> The virtio-blk device will soon be able to assign virtqueues to IOThreads,
> eliminating the single IOThread bottleneck. In order to do that, the I/O code
> path must support running in multiple threads.
> 
> This patch series removes the AioContext lock from the virtio-blk I/O code
> path, adds thread-safety where it is required, and ensures that Linux AIO and
> io_uring are available regardless of which thread calls into the block driver.
> With these changes virtio-blk is ready for the iothread-vq-mapping feature,
> which will be introduced in the next patch series.
> 
> Based-on: 20230913200045.1024233-1-stefanha@redhat.com ("[PATCH v3 0/4] virtio-blk: use blk_io_plug_call() instead of notification BH")
> Based-on: 20230912231037.826804-1-stefanha@redhat.com ("[PATCH v3 0/5] block-backend: process I/O in the current AioContext")
> 
> Stefan Hajnoczi (4):
>   block/file-posix: set up Linux AIO and io_uring in the current thread
>   virtio-blk: add lock to protect s->rq
>   virtio-blk: don't lock AioContext in the completion code path
>   virtio-blk: don't lock AioContext in the submission code path

Thanks, applied to the block branch.

Kevin

On Thu, Sep 14, 2023 at 10:00:57AM -0400, Stefan Hajnoczi wrote:
> The virtio-blk device will soon be able to assign virtqueues to IOThreads,
> eliminating the single IOThread bottleneck. In order to do that, the I/O code
> path must support running in multiple threads.
> 
> This patch series removes the AioContext lock from the virtio-blk I/O code
> path, adds thread-safety where it is required, and ensures that Linux AIO and
> io_uring are available regardless of which thread calls into the block driver.
> With these changes virtio-blk is ready for the iothread-vq-mapping feature,
> which will be introduced in the next patch series.
> 
> Based-on: 20230913200045.1024233-1-stefanha@redhat.com ("[PATCH v3 0/4] virtio-blk: use blk_io_plug_call() instead of notification BH")
> Based-on: 20230912231037.826804-1-stefanha@redhat.com ("[PATCH v3 0/5] block-backend: process I/O in the current AioContext")


virtio bits:

Reviewed-by: Michael S. Tsirkin <mst@redhat.com>

feel free to merge

> Stefan Hajnoczi (4):
>   block/file-posix: set up Linux AIO and io_uring in the current thread
>   virtio-blk: add lock to protect s->rq
>   virtio-blk: don't lock AioContext in the completion code path
>   virtio-blk: don't lock AioContext in the submission code path
> 
>  include/hw/virtio/virtio-blk.h |   3 +-
>  block/file-posix.c             |  99 +++++++++++++++---------------
>  hw/block/virtio-blk.c          | 106 +++++++++++++++------------------
>  3 files changed, 98 insertions(+), 110 deletions(-)
> 
> -- 
> 2.41.0