[PULL 07/33] virtio-blk: don't lock AioContext in the submission code path

Kevin Wolf posted 33 patches 11 months, 1 week ago
Maintainers: Kevin Wolf <kwolf@redhat.com>, Hanna Reitz <hreitz@redhat.com>, John Snow <jsnow@redhat.com>, Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>, Ari Sundholm <ari@tuxera.com>, Stefan Hajnoczi <stefanha@redhat.com>, Coiby Xu <Coiby.Xu@gmail.com>, Fam Zheng <fam@euphon.net>, Eric Blake <eblake@redhat.com>, Alberto Garcia <berto@igalia.com>, Wen Congyang <wencongyang2@huawei.com>, Xie Changlong <xiechanglong.d@gmail.com>, Stefano Stabellini <sstabellini@kernel.org>, Anthony Perard <anthony.perard@citrix.com>, Paul Durrant <paul@xen.org>, "Michael S. Tsirkin" <mst@redhat.com>, Paolo Bonzini <pbonzini@redhat.com>, "Daniel P. Berrangé" <berrange@redhat.com>, Eduardo Habkost <eduardo@habkost.net>, Markus Armbruster <armbru@redhat.com>, Michael Roth <michael.roth@amd.com>, Juan Quintela <quintela@redhat.com>, Peter Xu <peterx@redhat.com>, Fabiano Rosas <farosas@suse.de>, Leonardo Bras <leobras@redhat.com>, Zhang Chen <chen.zhang@intel.com>, Li Zhijian <lizhijian@fujitsu.com>, Jason Wang <jasowang@redhat.com>, Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>, Cleber Rosa <crosa@redhat.com>, David Hildenbrand <david@redhat.com>, "Philippe Mathieu-Daudé" <philmd@linaro.org>
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[PULL 07/33] virtio-blk: don't lock AioContext in the submission code path
Posted by Kevin Wolf 11 months, 1 week ago
From: Stefan Hajnoczi <stefanha@redhat.com>

There is no need to acquire the AioContext lock around blk_aio_*() or
blk_get_geometry() anymore. I/O plugging (defer_call()) also does not
require the AioContext lock anymore.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230914140101.1065008-5-stefanha@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 hw/block/virtio-blk.c | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
index f5315df042..e110f9718b 100644
--- a/hw/block/virtio-blk.c
+++ b/hw/block/virtio-blk.c
@@ -1111,7 +1111,6 @@ void virtio_blk_handle_vq(VirtIOBlock *s, VirtQueue *vq)
     MultiReqBuffer mrb = {};
     bool suppress_notifications = virtio_queue_get_notification(vq);
 
-    aio_context_acquire(blk_get_aio_context(s->blk));
     defer_call_begin();
 
     do {
@@ -1137,7 +1136,6 @@ void virtio_blk_handle_vq(VirtIOBlock *s, VirtQueue *vq)
     }
 
     defer_call_end();
-    aio_context_release(blk_get_aio_context(s->blk));
 }
 
 static void virtio_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq)
@@ -1168,7 +1166,6 @@ static void virtio_blk_dma_restart_bh(void *opaque)
         s->rq = NULL;
     }
 
-    aio_context_acquire(blk_get_aio_context(s->conf.conf.blk));
     while (req) {
         VirtIOBlockReq *next = req->next;
         if (virtio_blk_handle_request(req, &mrb)) {
@@ -1192,8 +1189,6 @@ static void virtio_blk_dma_restart_bh(void *opaque)
 
     /* Paired with inc in virtio_blk_dma_restart_cb() */
     blk_dec_in_flight(s->conf.conf.blk);
-
-    aio_context_release(blk_get_aio_context(s->conf.conf.blk));
 }
 
 static void virtio_blk_dma_restart_cb(void *opaque, bool running,
-- 
2.43.0