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61 lines
2.1 KiB
61 lines
2.1 KiB
8 months ago
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From 6b5cfed21e20b372090046a934387255ff4bda58 Mon Sep 17 00:00:00 2001
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From: Stefan Hajnoczi <stefanha@redhat.com>
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Date: Tue, 5 Dec 2023 13:20:01 -0500
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Subject: [PATCH 084/101] aio: make aio_context_acquire()/aio_context_release()
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a no-op
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RH-Author: Kevin Wolf <kwolf@redhat.com>
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RH-MergeRequest: 214: Remove AioContext lock
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RH-Jira: RHEL-15965
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RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
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RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
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RH-Commit: [15/26] 723dcada900aaf08862e8221921be22506b561a8 (kmwolf/centos-qemu-kvm)
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aio_context_acquire()/aio_context_release() has been replaced by
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fine-grained locking to protect state shared by multiple threads. The
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AioContext lock still plays the role of balancing locking in
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AIO_WAIT_WHILE() and many functions in QEMU either require that the
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AioContext lock is held or not held for this reason. In other words, the
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AioContext lock is purely there for consistency with itself and serves
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no real purpose anymore.
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Stop actually acquiring/releasing the lock in
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aio_context_acquire()/aio_context_release() so that subsequent patches
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can remove callers across the codebase incrementally.
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I have performed "make check" and qemu-iotests stress tests across
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x86-64, ppc64le, and aarch64 to confirm that there are no failures as a
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result of eliminating the lock.
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Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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Reviewed-by: Eric Blake <eblake@redhat.com>
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Acked-by: Kevin Wolf <kwolf@redhat.com>
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Message-ID: <20231205182011.1976568-5-stefanha@redhat.com>
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Signed-off-by: Kevin Wolf <kwolf@redhat.com>
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---
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util/async.c | 4 ++--
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1 file changed, 2 insertions(+), 2 deletions(-)
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diff --git a/util/async.c b/util/async.c
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index 8f90ddc304..04ee83d220 100644
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--- a/util/async.c
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+++ b/util/async.c
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@@ -725,12 +725,12 @@ void aio_context_unref(AioContext *ctx)
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void aio_context_acquire(AioContext *ctx)
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{
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- qemu_rec_mutex_lock(&ctx->lock);
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+ /* TODO remove this function */
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}
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void aio_context_release(AioContext *ctx)
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{
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- qemu_rec_mutex_unlock(&ctx->lock);
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+ /* TODO remove this function */
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}
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QEMU_DEFINE_STATIC_CO_TLS(AioContext *, my_aiocontext)
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--
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2.39.3
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