perf tools: Introduce weak alternative to sched_getcpu()

tip:perf/core tip-bot for Arnaldo Carvalho de Melo 1 participant 1 message Jul 13, 2016 perf events

Share & tools

tip-bot for Arnaldo Carvalho de Melo

author merge bot

2016-07-13 07:18 UTC #0 lore raw

Commit-ID:  c7007e983682b31d91e9ad7c3e85c49ffcc3651f
Gitweb:     http://git.kernel.org/tip/c7007e983682b31d91e9ad7c3e85c49ffcc3651f
Author:     Arnaldo Carvalho de Melo <[email protected]>
AuthorDate: Tue, 12 Jul 2016 10:29:31 -0300
Committer:  Arnaldo Carvalho de Melo <[email protected]>
CommitDate: Tue, 12 Jul 2016 15:20:34 -0300

perf tools: Introduce weak alternative to sched_getcpu()

Which is just a wrapper for sys_getcpu and is not present in at least musl libc.

Cc Adrian Hunter <[email protected]>

Cc David Ahern <[email protected]>

Cc Jiri Olsa <[email protected]>

Cc Namhyung Kim <[email protected]>

Cc Wang Nan <[email protected]>

Link http://lkml.kernel.org/n/[email protected] open here

Signed-off-by Arnaldo Carvalho de Melo <[email protected]>

---
 tools/arch/x86/include/asm/unistd_32.h |  3 +++
 tools/arch/x86/include/asm/unistd_64.h |  3 +++
 tools/perf/util/cloexec.c              | 14 ++++++++++----
 tools/perf/util/util.h                 |  4 ++++
 4 files changed, 20 insertions(+), 4 deletions(-)

tools/arch/x86/include/asm/unistd_32.h +3 -0

index cf33ab0..88b3f8c 100644
@@ -7,3 +7,6 @@
 #ifndef __NR_gettid
 # define __NR_gettid 224
 #endif
+#ifndef __NR_getcpu
+# define __NR_getcpu 318
+#endif

tools/arch/x86/include/asm/unistd_64.h +3 -0

index 2c98356..fbdb70e 100644
@@ -7,3 +7,6 @@
 #ifndef __NR_gettid
 # define __NR_gettid 186
 #endif
+#ifndef __NR_getcpu
+# define __NR_getcpu 309
+#endif

tools/perf/util/cloexec.c +10 -4

index fde772d..f0dcd0e 100644
@@ -4,18 +4,24 @@
 #include "cloexec.h"
 #include "asm/bug.h"
 #include "debug.h"
+#include <unistd.h>
+#include <asm/unistd.h>
+#include <sys/syscall.h>
 
 static unsigned long flag = PERF_FLAG_FD_CLOEXEC;
 
-#ifdef __GLIBC_PREREQ
-#if !__GLIBC_PREREQ(2, 6)
 int __weak sched_getcpu(void)
 {
+#ifdef __NR_getcpu
+	unsigned cpu;
+	int err = syscall(__NR_getcpu, &cpu, NULL, NULL);
+	if (!err)
+		return cpu;
+#else
 	errno = ENOSYS;
+#endif
 	return -1;
 }
-#endif
-#endif
 
 static int perf_flag_probe(void)
 {

tools/perf/util/util.h +4 -0

index 2370cfb..d8d41ef 100644
@@ -361,4 +361,8 @@ void print_binary(unsigned char *data, size_t len,
 		  size_t bytes_per_line, print_binary_t printer,
 		  void *extra);
 
+#ifndef __GLIBC__
+extern int sched_getcpu(void);
+#endif
+
 #endif /* GIT_COMPAT_UTIL_H */