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[PULL 18/33] aio: make aio_context_acquire()/aio_context_release() a no-
From: |
Kevin Wolf |
Subject: |
[PULL 18/33] aio: make aio_context_acquire()/aio_context_release() a no-op |
Date: |
Thu, 21 Dec 2023 22:23:23 +0100 |
From: Stefan Hajnoczi <stefanha@redhat.com>
aio_context_acquire()/aio_context_release() has been replaced by
fine-grained locking to protect state shared by multiple threads. The
AioContext lock still plays the role of balancing locking in
AIO_WAIT_WHILE() and many functions in QEMU either require that the
AioContext lock is held or not held for this reason. In other words, the
AioContext lock is purely there for consistency with itself and serves
no real purpose anymore.
Stop actually acquiring/releasing the lock in
aio_context_acquire()/aio_context_release() so that subsequent patches
can remove callers across the codebase incrementally.
I have performed "make check" and qemu-iotests stress tests across
x86-64, ppc64le, and aarch64 to confirm that there are no failures as a
result of eliminating the lock.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Acked-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231205182011.1976568-5-stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
util/async.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/util/async.c b/util/async.c
index 8f90ddc304..04ee83d220 100644
--- a/util/async.c
+++ b/util/async.c
@@ -725,12 +725,12 @@ void aio_context_unref(AioContext *ctx)
void aio_context_acquire(AioContext *ctx)
{
- qemu_rec_mutex_lock(&ctx->lock);
+ /* TODO remove this function */
}
void aio_context_release(AioContext *ctx)
{
- qemu_rec_mutex_unlock(&ctx->lock);
+ /* TODO remove this function */
}
QEMU_DEFINE_STATIC_CO_TLS(AioContext *, my_aiocontext)
--
2.43.0
- [PULL 09/33] vl: Improve error message for conflicting -incoming and -loadvm, (continued)
- [PULL 09/33] vl: Improve error message for conflicting -incoming and -loadvm, Kevin Wolf, 2023/12/21
- [PULL 08/33] block: Fix crash when loading snapshot on inactive node, Kevin Wolf, 2023/12/21
- [PULL 10/33] iotests: Basic tests for internal snapshots, Kevin Wolf, 2023/12/21
- [PULL 11/33] scsi: only access SCSIDevice->requests from one thread, Kevin Wolf, 2023/12/21
- [PULL 12/33] virtio-scsi: don't lock AioContext around virtio_queue_aio_attach_host_notifier(), Kevin Wolf, 2023/12/21
- [PULL 13/33] scsi: don't lock AioContext in I/O code path, Kevin Wolf, 2023/12/21
- [PULL 14/33] dma-helpers: don't lock AioContext in dma_blk_cb(), Kevin Wolf, 2023/12/21
- [PULL 15/33] virtio-scsi: replace AioContext lock with tmf_bh_lock, Kevin Wolf, 2023/12/21
- [PULL 16/33] scsi: assert that callbacks run in the correct AioContext, Kevin Wolf, 2023/12/21
- [PULL 17/33] tests: remove aio_context_acquire() tests, Kevin Wolf, 2023/12/21
- [PULL 18/33] aio: make aio_context_acquire()/aio_context_release() a no-op,
Kevin Wolf <=
- [PULL 19/33] graph-lock: remove AioContext locking, Kevin Wolf, 2023/12/21
- [PULL 22/33] scsi: remove AioContext locking, Kevin Wolf, 2023/12/21
- [PULL 20/33] block: remove AioContext locking, Kevin Wolf, 2023/12/21
- [PULL 21/33] block: remove bdrv_co_lock(), Kevin Wolf, 2023/12/21
- [PULL 23/33] aio-wait: draw equivalence between AIO_WAIT_WHILE() and AIO_WAIT_WHILE_UNLOCKED(), Kevin Wolf, 2023/12/21
- [PULL 25/33] docs: remove AioContext lock from IOThread docs, Kevin Wolf, 2023/12/21
- [PULL 26/33] scsi: remove outdated AioContext lock comment, Kevin Wolf, 2023/12/21
- [PULL 24/33] aio: remove aio_context_acquire()/aio_context_release() API, Kevin Wolf, 2023/12/21
- [PULL 27/33] job: remove outdated AioContext locking comments, Kevin Wolf, 2023/12/21
- [PULL 28/33] block: remove outdated AioContext locking comments, Kevin Wolf, 2023/12/21