[PATCH 4/7] perf/bench-futex: Add --mlockall parameter

Davidlohr Bueso
2021-08-09T04:33:28Z

This adds, across all futex benchmarks, the -m/--mlockall option
which is a common operation for realtime workloads by not incurring
in page faults in paths that want determinism. As such, threads
started after a call to mlockall(2) will generate page faults
immediately since the new stack is immediately forced to memory,
due to the MCL_FUTURE flag.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
---
tools/perf/bench/futex-hash.c | 7 +++++++
tools/perf/bench/futex-lock-pi.c | 7 +++++++
tools/perf/bench/futex-requeue.c | 7 +++++++
tools/perf/bench/futex-wake-parallel.c | 8 ++++++++
tools/perf/bench/futex-wake.c | 8 ++++++++
tools/perf/bench/futex.h | 1 +
6 files changed, 38 insertions(+)

diff --git a/tools/perf/bench/futex-hash.c b/tools/perf/bench/futex-hash.c
index b71a34204b79..af9fbb409472 100644
--- a/tools/perf/bench/futex-hash.c
+++ b/tools/perf/bench/futex-hash.c
@@ -20,6 +20,7 @@
#include <linux/kernel.h>
#include <linux/zalloc.h>
#include <sys/time.h>
+#include <sys/mman.h>
#include <perf/cpumap.h>

#include "../util/stat.h"
@@ -55,6 +56,7 @@ static const struct option options[] = {
OPT_UINTEGER('f', "futexes", &params.nfutexes, "Specify amount of futexes per threads"),
OPT_BOOLEAN( 's', "silent", &params.silent, "Silent mode: do not display data/details"),
OPT_BOOLEAN( 'S', "shared", &params.fshared, "Use shared futexes instead of private ones"),
+ OPT_BOOLEAN( 'm', "mlockall", &params.mlockall, "Lock all current and future memory"),
OPT_END()
};

@@ -141,6 +143,11 @@ int bench_futex_hash(int argc, const char **argv)
act.sa_sigaction = toggle_done;
sigaction(SIGINT, &act, NULL);

+ if (params.mlockall) {
+ if (mlockall(MCL_CURRENT | MCL_FUTURE))
+ err(EXIT_FAILURE, "mlockall");
+ }
+
if (!params.nthreads) /* default to the number of CPUs */
params.nthreads = cpu->nr;

diff --git a/tools/perf/bench/futex-lock-pi.c b/tools/perf/bench/futex-lock-pi.c
index bc208edf3de3..d2927d2eb3f7 100644
--- a/tools/perf/bench/futex-lock-pi.c
+++ b/tools/perf/bench/futex-lock-pi.c
@@ -21,6 +21,7 @@
#include <err.h>
#include <stdlib.h>
#include <sys/time.h>
+#include <sys/mman.h>

struct worker {
int tid;
@@ -47,6 +48,7 @@ static const struct option options[] = {
OPT_BOOLEAN( 'M', "multi", &params.multi, "Use multiple futexes"),
OPT_BOOLEAN( 's', "silent", &params.silent, "Silent mode: do not display data/details"),
OPT_BOOLEAN( 'S', "shared", &params.fshared, "Use shared futexes instead of private ones"),
+ OPT_BOOLEAN( 'm', "mlockall", &params.mlockall, "Lock all current and future memory"),
OPT_END()
};

@@ -164,6 +166,11 @@ int bench_futex_lock_pi(int argc, const char **argv)
act.sa_sigaction = toggle_done;
sigaction(SIGINT, &act, NULL);

+ if (params.mlockall) {
+ if (mlockall(MCL_CURRENT | MCL_FUTURE))
+ err(EXIT_FAILURE, "mlockall");
+ }
+
if (!params.nthreads)
params.nthreads = cpu->nr;

diff --git a/tools/perf/bench/futex-requeue.c b/tools/perf/bench/futex-requeue.c
index 4001312122be..88cb7e2a6729 100644
--- a/tools/perf/bench/futex-requeue.c
+++ b/tools/perf/bench/futex-requeue.c
@@ -27,6 +27,7 @@
#include <err.h>
#include <stdlib.h>
#include <sys/time.h>
+#include <sys/mman.h>

static u_int32_t futex1 = 0, futex2 = 0;

@@ -50,6 +51,7 @@ static const struct option options[] = {
OPT_UINTEGER('q', "nrequeue", &params.nrequeue, "Specify amount of threads to requeue at once"),
OPT_BOOLEAN( 's', "silent", &params.silent, "Silent mode: do not display data/details"),
OPT_BOOLEAN( 'S', "shared", &params.fshared, "Use shared futexes instead of private ones"),
+ OPT_BOOLEAN( 'm', "mlockall", &params.mlockall, "Lock all current and future memory"),
OPT_END()
};

@@ -133,6 +135,11 @@ int bench_futex_requeue(int argc, const char **argv)
act.sa_sigaction = toggle_done;
sigaction(SIGINT, &act, NULL);

+ if (params.mlockall) {
+ if (mlockall(MCL_CURRENT | MCL_FUTURE))
+ err(EXIT_FAILURE, "mlockall");
+ }
+
if (!params.nthreads)
params.nthreads = cpu->nr;

diff --git a/tools/perf/bench/futex-wake-parallel.c b/tools/perf/bench/futex-wake-parallel.c
index ea4fdea6e2f3..ef1f8237fd81 100644
--- a/tools/perf/bench/futex-wake-parallel.c
+++ b/tools/perf/bench/futex-wake-parallel.c
@@ -34,6 +34,7 @@ int bench_futex_wake_parallel(int argc __maybe_unused, const char **argv __maybe
#include <err.h>
#include <stdlib.h>
#include <sys/time.h>
+#include <sys/mman.h>

struct thread_data {
pthread_t worker;
@@ -61,6 +62,8 @@ static const struct option options[] = {
OPT_UINTEGER('w', "nwakers", &params.nwakes, "Specify amount of waking threads"),
OPT_BOOLEAN( 's', "silent", &params.silent, "Silent mode: do not display data/details"),
OPT_BOOLEAN( 'S', "shared", &params.fshared, "Use shared futexes instead of private ones"),
+ OPT_BOOLEAN( 'm', "mlockall", &params.mlockall, "Lock all current and future memory"),
+
OPT_END()
};

@@ -238,6 +241,11 @@ int bench_futex_wake_parallel(int argc, const char **argv)
act.sa_sigaction = toggle_done;
sigaction(SIGINT, &act, NULL);

+ if (params.mlockall) {
+ if (mlockall(MCL_CURRENT | MCL_FUTURE))
+ err(EXIT_FAILURE, "mlockall");
+ }
+
cpu = perf_cpu_map__new(NULL);
if (!cpu)
err(EXIT_FAILURE, "calloc");
diff --git a/tools/perf/bench/futex-wake.c b/tools/perf/bench/futex-wake.c
index 1cf651c8ee5c..40e492c7996a 100644
--- a/tools/perf/bench/futex-wake.c
+++ b/tools/perf/bench/futex-wake.c
@@ -27,6 +27,7 @@
#include <err.h>
#include <stdlib.h>
#include <sys/time.h>
+#include <sys/mman.h>

/* all threads will block on the same futex */
static u_int32_t futex1 = 0;
@@ -51,6 +52,8 @@ static const struct option options[] = {
OPT_UINTEGER('w', "nwakes", &params.nwakes, "Specify amount of threads to wake at once"),
OPT_BOOLEAN( 's', "silent", &params.silent, "Silent mode: do not display data/details"),
OPT_BOOLEAN( 'S', "shared", &params.fshared, "Use shared futexes instead of private ones"),
+ OPT_BOOLEAN( 'm', "mlockall", &params.mlockall, "Lock all current and future memory"),
+
OPT_END()
};

@@ -141,6 +144,11 @@ int bench_futex_wake(int argc, const char **argv)
act.sa_sigaction = toggle_done;
sigaction(SIGINT, &act, NULL);

+ if (params.mlockall) {
+ if (mlockall(MCL_CURRENT | MCL_FUTURE))
+ err(EXIT_FAILURE, "mlockall");
+ }
+
if (!params.nthreads)
params.nthreads = cpu->nr;

diff --git a/tools/perf/bench/futex.h b/tools/perf/bench/futex.h
index f7cd22bbd677..1c8fa469993f 100644
--- a/tools/perf/bench/futex.h
+++ b/tools/perf/bench/futex.h
@@ -19,6 +19,7 @@ static int futex_flag = 0;
struct bench_futex_parameters {
bool silent;
bool fshared;
+ bool mlockall;
bool multi; /* lock-pi */
unsigned int runtime; /* seconds*/
unsigned int nthreads;
--
2.26.2