Summary: It doesn't exist anywhere else, and `syscall` isn't even defined on Windows, so this completely failed to compile before.
Reviewed By: yfeldblum
Differential Revision:
D3623382
fbshipit-source-id:
302093ddc96d6465e0dcc1883747229a7fb25a84
#include <folly/Portability.h>
#include <folly/portability/Unistd.h>
-#if !defined(__NR_membarrier) && FOLLY_X64 && !FOLLY_MOBILE
+#if !defined(__NR_membarrier) && FOLLY_X64 && !FOLLY_MOBILE && \
+ defined(__linux__)
#define __NR_membarrier 324
#define MEMBARRIER_CMD_QUERY 0
#define MEMBARRIER_CMD_SHARED 1