[PATCH 0/1] MR6963: ntdll: Use sched_getcpu instead of the getcpu syscall.

[Brendan Shanks (＠bshanks)]

`sched_getcpu()` has been supported since glibc 2.6 (2007), and is faster since it can use a vsyscall. Plus, FreeBSD implements it as well.

[PATCH 1/1] ntdll: Use sched_getcpu instead of the getcpu syscall.

[Brendan Shanks]

From: Brendan Shanks

---
 configure.ac             | 1 +
 dlls/ntdll/unix/thread.c | 9 ++++++---
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/configure.ac b/configure.ac
index ac710721ae6..fa57b75a0fd 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2079,6 +2079,7 @@ AC_CHECK_FUNCS(\
    posix_fadvise \
    posix_fallocate \
    prctl \
+	sched_getcpu \
    sched_yield \
    setproctitle \
    setprogname \
diff --git a/dlls/ntdll/unix/thread.c b/dlls/ntdll/unix/thread.c
index a7114825118..1f7a46b832d 100644
--- a/dlls/ntdll/unix/thread.c
+++ b/dlls/ntdll/unix/thread.c
@@ -37,6 +37,9 @@
 #include <sys/types.h>
 #include <unistd.h>
 #include <sys/mman.h>
+#ifdef HAVE_SCHED_H
+#include <sched.h>
+#endif
 #ifdef HAVE_SYS_TIMES_H
 #include <sys/times.h>
 #endif
@@ -2560,9 +2563,9 @@ ULONG WINAPI NtGetCurrentProcessorNumber(void)
 {
     ULONG processor;

-#if defined(__linux__) && defined(__NR_getcpu)
-    int res = syscall(__NR_getcpu, &processor, NULL, NULL);
-    if (res != -1) return processor;
+#if defined(HAVE_SCHED_GETCPU)
+    int res = sched_getcpu();
+    if (res >= 0) return res;
 #endif

if (peb->NumberOfProcessors > 1)