[PATCH] test-aio-multithread: do not use mb_read/mb_set for simple flags

[PATCH] test-aio-multithread: do not use mb_read/mb_set for simple flags

[Paolo Bonzini]

The remaining use of mb_read/mb_set is just to force a thread to exit
eventually.  It does not order two memory accesses and therefore can be
just read/set.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 tests/unit/test-aio-multithread.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/tests/unit/test-aio-multithread.c b/tests/unit/test-aio-multithread.c
index a555cc883505..3c61526a0b46 100644
--- a/tests/unit/test-aio-multithread.c
+++ b/tests/unit/test-aio-multithread.c
@@ -202,7 +202,7 @@ static CoMutex comutex;
 
 static void coroutine_fn test_multi_co_mutex_entry(void *opaque)
 {
-    while (!qatomic_mb_read(&now_stopping)) {
+    while (!qatomic_read(&now_stopping)) {
         qemu_co_mutex_lock(&comutex);
         counter++;
         qemu_co_mutex_unlock(&comutex);
@@ -236,7 +236,7 @@ static void test_multi_co_mutex(int threads, int seconds)
 
     g_usleep(seconds * 1000000);
 
-    qatomic_mb_set(&now_stopping, true);
+    qatomic_set(&now_stopping, true);
     while (running > 0) {
         g_usleep(100000);
     }
@@ -327,7 +327,7 @@ static void mcs_mutex_unlock(void)
 
 static void test_multi_fair_mutex_entry(void *opaque)
 {
-    while (!qatomic_mb_read(&now_stopping)) {
+    while (!qatomic_read(&now_stopping)) {
         mcs_mutex_lock();
         counter++;
         mcs_mutex_unlock();
@@ -355,7 +355,7 @@ static void test_multi_fair_mutex(int threads, int seconds)
 
     g_usleep(seconds * 1000000);
 
-    qatomic_mb_set(&now_stopping, true);
+    qatomic_set(&now_stopping, true);
     while (running > 0) {
         g_usleep(100000);
     }
@@ -383,7 +383,7 @@ static QemuMutex mutex;
 
 static void test_multi_mutex_entry(void *opaque)
 {
-    while (!qatomic_mb_read(&now_stopping)) {
+    while (!qatomic_read(&now_stopping)) {
         qemu_mutex_lock(&mutex);
         counter++;
         qemu_mutex_unlock(&mutex);
@@ -411,7 +411,7 @@ static void test_multi_mutex(int threads, int seconds)
 
     g_usleep(seconds * 1000000);
 
-    qatomic_mb_set(&now_stopping, true);
+    qatomic_set(&now_stopping, true);
     while (running > 0) {
         g_usleep(100000);
     }
-- 
2.40.0

Re: [PATCH] test-aio-multithread: do not use mb_read/mb_set for simple flags

[Richard Henderson]

On 4/28/23 12:12, Paolo Bonzini wrote:
> The remaining use of mb_read/mb_set is just to force a thread to exit
> eventually.  It does not order two memory accesses and therefore can be
> just read/set.
> 
> Signed-off-by: Paolo Bonzini<pbonzini@redhat.com>
> ---
>   tests/unit/test-aio-multithread.c | 12 ++++++------
>   1 file changed, 6 insertions(+), 6 deletions(-)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~

Re: [PATCH] test-aio-multithread: do not use mb_read/mb_set for simple flags

[Stefan Hajnoczi]

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On Fri, Apr 28, 2023 at 01:12:48PM +0200, Paolo Bonzini wrote:
> The remaining use of mb_read/mb_set is just to force a thread to exit
> eventually.  It does not order two memory accesses and therefore can be
> just read/set.
> 
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  tests/unit/test-aio-multithread.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>

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