qemu /
qemu /
e3a3b6ec8169eab2feb241b4982585001512cd55 qemu-coroutine-lock: add smp_mb__after_rmw()
mutex->from_push and mutex->handoff in qemu-coroutine-lock implement
the familiar pattern:
write a write b
smp_mb() smp_mb()
read b read a
The memory barrier is required by the C memory model even after a
SEQ_CST read-modify-write operation such as QSLIST_INSERT_HEAD_ATOMIC.
Add it and avoid the unclear qatomic_mb_read() operation.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
1 file changed