Replaced WFE instruction with ISB in mi_atomic_yield on ARM64 for non Windows as it significantly improves performance

akaStiX · akaStiX · commit 3a7214592931 · 2026-02-02T11:51:32.000+01:00
diff --git a/include/mimalloc/atomic.h b/include/mimalloc/atomic.h
@@ -382,7 +382,7 @@ static inline void mi_atomic_yield(void) {
 }
 #elif defined(__aarch64__)
 static inline void mi_atomic_yield(void) {
-  __asm__ volatile("wfe");
+  __asm__ volatile("isb");
 }
 #elif defined(__arm__)
 #if __ARM_ARCH >= 7

Original file line number	Diff line number	Diff line change
`@@ -382,7 +382,7 @@ static inline void mi_atomic_yield(void) {`
`382`	`382`	`}`
`383`	`383`	`#elif defined(__aarch64__)`
`384`	`384`	`static inline void mi_atomic_yield(void) {`
`385`		`- __asm__ volatile("wfe");`
	`385`	`+ __asm__ volatile("isb");`
`386`	`386`	`}`
`387`	`387`	`#elif defined(__arm__)`
`388`	`388`	`#if __ARM_ARCH >= 7`