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author | Stefan Hajnoczi <stefanha@redhat.com> | 2023-05-30 14:09:54 -0400 |
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committer | Stefan Hajnoczi <stefanha@redhat.com> | 2023-06-01 07:34:03 -0400 |
commit | 41abca8c39244b7eeb06378c4aa18b10e0645a1c (patch) | |
tree | 5bf64a2c7e1e223ac1021b12663543892bb10250 /include | |
parent | c6a5fc2ac76c5ab709896ee1b0edd33685a67ed1 (diff) | |
download | qemu-41abca8c39244b7eeb06378c4aa18b10e0645a1c.zip qemu-41abca8c39244b7eeb06378c4aa18b10e0645a1c.tar.gz qemu-41abca8c39244b7eeb06378c4aa18b10e0645a1c.tar.bz2 |
block: add blk_io_plug_call() API
Introduce a new API for thread-local blk_io_plug() that does not
traverse the block graph. The goal is to make blk_io_plug() multi-queue
friendly.
Instead of having block drivers track whether or not we're in a plugged
section, provide an API that allows them to defer a function call until
we're unplugged: blk_io_plug_call(fn, opaque). If blk_io_plug_call() is
called multiple times with the same fn/opaque pair, then fn() is only
called once at the end of the function - resulting in batching.
This patch introduces the API and changes blk_io_plug()/blk_io_unplug().
blk_io_plug()/blk_io_unplug() no longer require a BlockBackend argument
because the plug state is now thread-local.
Later patches convert block drivers to blk_io_plug_call() and then we
can finally remove .bdrv_co_io_plug() once all block drivers have been
converted.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Acked-by: Kevin Wolf <kwolf@redhat.com>
Message-id: 20230530180959.1108766-2-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'include')
-rw-r--r-- | include/sysemu/block-backend-io.h | 13 |
1 files changed, 3 insertions, 10 deletions
diff --git a/include/sysemu/block-backend-io.h b/include/sysemu/block-backend-io.h index d62a7ee..be4dcef 100644 --- a/include/sysemu/block-backend-io.h +++ b/include/sysemu/block-backend-io.h @@ -100,16 +100,9 @@ void blk_iostatus_set_err(BlockBackend *blk, int error); int blk_get_max_iov(BlockBackend *blk); int blk_get_max_hw_iov(BlockBackend *blk); -/* - * blk_io_plug/unplug are thread-local operations. This means that multiple - * IOThreads can simultaneously call plug/unplug, but the caller must ensure - * that each unplug() is called in the same IOThread of the matching plug(). - */ -void coroutine_fn blk_co_io_plug(BlockBackend *blk); -void co_wrapper blk_io_plug(BlockBackend *blk); - -void coroutine_fn blk_co_io_unplug(BlockBackend *blk); -void co_wrapper blk_io_unplug(BlockBackend *blk); +void blk_io_plug(void); +void blk_io_unplug(void); +void blk_io_plug_call(void (*fn)(void *), void *opaque); AioContext *blk_get_aio_context(BlockBackend *blk); BlockAcctStats *blk_get_stats(BlockBackend *blk); |