You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
61 lines
2.1 KiB
61 lines
2.1 KiB
9 months ago
|
From 6b5cfed21e20b372090046a934387255ff4bda58 Mon Sep 17 00:00:00 2001
|
||
|
|
From: Stefan Hajnoczi <stefanha@redhat.com>
|
||
|
|
Date: Tue, 5 Dec 2023 13:20:01 -0500
|
||
|
|
Subject: [PATCH 084/101] aio: make aio_context_acquire()/aio_context_release()
|
||
|
|
a no-op
|
||
|
|
|
||
|
|
RH-Author: Kevin Wolf <kwolf@redhat.com>
|
||
|
|
RH-MergeRequest: 214: Remove AioContext lock
|
||
|
|
RH-Jira: RHEL-15965
|
||
|
|
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
|
||
|
|
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
|
||
|
|
RH-Commit: [15/26] 723dcada900aaf08862e8221921be22506b561a8 (kmwolf/centos-qemu-kvm)
|
||
|
|
|
||
|
|
aio_context_acquire()/aio_context_release() has been replaced by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)
|
||
|
|
--
|
||
|
|
2.39.3
|
||
|
|
|