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| author | Paolo Bonzini <pbonzini@redhat.com> | 2023-03-03 11:03:52 +0100 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2023-03-07 12:39:50 +0100 |
| commit | b532526a07ef3b903ead2e055fe6cc87b41057a3 (patch) | |
| tree | 34054b0a98fb09f532a0cb31494f4a20d85efbd1 /include | |
| parent | 2482aeea4195ad84cf3d4e5b15b28ec5b420ed5a (diff) | |
| download | focaccia-qemu-b532526a07ef3b903ead2e055fe6cc87b41057a3.tar.gz focaccia-qemu-b532526a07ef3b903ead2e055fe6cc87b41057a3.zip | |
aio-wait: switch to smp_mb__after_rmw()
The barrier comes after an atomic increment, so it is enough to use smp_mb__after_rmw(); this avoids a double barrier on x86 systems. Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'include')
| -rw-r--r-- | include/block/aio-wait.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/block/aio-wait.h b/include/block/aio-wait.h index dd9a7f6461..da13357bb8 100644 --- a/include/block/aio-wait.h +++ b/include/block/aio-wait.h @@ -85,7 +85,7 @@ extern AioWait global_aio_wait; /* Increment wait_->num_waiters before evaluating cond. */ \ qatomic_inc(&wait_->num_waiters); \ /* Paired with smp_mb in aio_wait_kick(). */ \ - smp_mb(); \ + smp_mb__after_rmw(); \ if (ctx_ && in_aio_context_home_thread(ctx_)) { \ while ((cond)) { \ aio_poll(ctx_, true); \ |