perf bench futex: Support operations for shared futexes
Unlike futex-hash, requeuing and wakeup benchmarks do not support shared
futexes, limiting the usefulness of the programs. Correct this, and
allow using the local -S parameter. The default remains using private
futexes.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Davidlohr Bueso <dbueso@suse.de>
Link: http://lkml.kernel.org/r/1412008868-22328-1-git-send-email-dave@stgolabs.net
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/bench/futex-hash.c b/tools/perf/bench/futex-hash.c
index a84206e..fc9bebd 100644
--- a/tools/perf/bench/futex-hash.c
+++ b/tools/perf/bench/futex-hash.c
@@ -26,6 +26,7 @@
/* amount of futexes per thread */
static unsigned int nfutexes = 1024;
static bool fshared = false, done = false, silent = false;
+static int futex_flag = 0;
struct timeval start, end, runtime;
static pthread_mutex_t thread_lock;
@@ -75,8 +76,7 @@
* such as internal waitqueue handling, thus enlarging
* the critical region protected by hb->lock.
*/
- ret = futex_wait(&w->futex[i], 1234, NULL,
- fshared ? 0 : FUTEX_PRIVATE_FLAG);
+ ret = futex_wait(&w->futex[i], 1234, NULL, futex_flag);
if (!silent &&
(!ret || errno != EAGAIN || errno != EWOULDBLOCK))
warn("Non-expected futex return call");
@@ -135,6 +135,9 @@
if (!worker)
goto errmem;
+ if (!fshared)
+ futex_flag = FUTEX_PRIVATE_FLAG;
+
printf("Run summary [PID %d]: %d threads, each operating on %d [%s] futexes for %d secs.\n\n",
getpid(), nthreads, nfutexes, fshared ? "shared":"private", nsecs);