MDEV-21452 fixup: Avoid an unnecessary mutex operation

dr-m · dr-m · commit c2df3d30c065 · 2022-08-19T09:21:02.000+03:00
diff --git a/extra/mariabackup/xtrabackup.cc b/extra/mariabackup/xtrabackup.cc
@@ -2477,11 +2477,11 @@ xb_write_delta_metadata(const char *filename, const xb_delta_info_t *info)
 /* ================= backup ================= */
 void xtrabackup_io_throttling()
 {
-  if (!xtrabackup_backup)
+  if (!xtrabackup_backup || !xtrabackup_throttle)
     return;
 
   mysql_mutex_lock(&log_sys.mutex);
-  if (xtrabackup_throttle && (io_ticket--) < 0)
+  if (io_ticket-- < 0)
     mysql_cond_wait(&wait_throttle, &log_sys.mutex);
   mysql_mutex_unlock(&log_sys.mutex);
 }

Original file line number	Diff line number	Diff line change
`@@ -2477,11 +2477,11 @@ xb_write_delta_metadata(const char filename, const xb_delta_info_t info)`
`2477`	`2477`	`/* ================= backup ================= */`
`2478`	`2478`	`void xtrabackup_io_throttling()`
`2479`	`2479`	`{`
`2480`		`- if (!xtrabackup_backup)`
	`2480`	`+ if (!xtrabackup_backup \|\| !xtrabackup_throttle)`
`2481`	`2481`	`return;`
`2482`	`2482`
`2483`	`2483`	`mysql_mutex_lock(&log_sys.mutex);`
`2484`		`- if (xtrabackup_throttle && (io_ticket--) < 0)`
	`2484`	`+ if (io_ticket-- < 0)`
`2485`	`2485`	`mysql_cond_wait(&wait_throttle, &log_sys.mutex);`
`2486`	`2486`	`mysql_mutex_unlock(&log_sys.mutex);`
`2487`	`2487`	`}`