[PATCH 2/3] perf/bench-futex: Add --mlockall parameter

From: Davidlohr Bueso
Date: Thu Aug 05 2021 - 21:33:42 EST

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 are deterministic. 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@xxxxxxx>
---
tools/perf/bench/futex-hash.c | 9 +++++++++
tools/perf/bench/futex-lock-pi.c | 9 +++++++++
tools/perf/bench/futex-requeue.c | 9 +++++++++
tools/perf/bench/futex-wake-parallel.c | 9 +++++++++
tools/perf/bench/futex-wake.c | 9 +++++++++
5 files changed, 45 insertions(+)

diff --git a/tools/perf/bench/futex-hash.c b/tools/perf/bench/futex-hash.c
index 2d86602f89e2..ba8ceff4e098 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"
@@ -51,6 +52,7 @@ struct parameters {
unsigned int runtime;
bool silent;
bool fshared;
+ bool mlockall;
};

static struct parameters params = {
@@ -69,6 +71,8 @@ static const struct option options[] = {
"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()
};

@@ -155,6 +159,11 @@ 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 9fc994beb933..ab387e73839e 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;
@@ -44,6 +45,7 @@ struct parameters {
bool multi;
bool silent;
bool fshared;
+ bool mlockall;
};

static struct parameters params = {
@@ -61,6 +63,8 @@ static const struct option options[] = {
"Params.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()
};

@@ -178,6 +182,11 @@ 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 b65761e98245..51f2c0d5e6f8 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;

@@ -43,6 +44,7 @@ struct parameters {
unsigned int nrequeue;
bool silent;
bool fshared;
+ bool mlockall;
};

static struct parameters params = {
@@ -62,6 +64,8 @@ static const struct option options[] = {
"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()
};

@@ -145,6 +149,11 @@ 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 a80dfff5fe37..d6d71374f535 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;
@@ -60,6 +61,7 @@ struct parameters {
unsigned int nblocked_threads;
bool silent;
bool fshared;
+ bool mlockall;
};

static struct parameters params;
@@ -73,6 +75,8 @@ static const struct option options[] = {
"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()
};

@@ -250,6 +254,11 @@ 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 22763774ede7..66f1338d66bc 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;
@@ -44,6 +45,7 @@ struct parameters {
unsigned int nwakes;
bool silent;
bool fshared;
+ bool mlockall;
};

static struct parameters params = {
@@ -63,6 +65,8 @@ static const struct option options[] = {
"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()
};

@@ -153,6 +157,11 @@ 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;

--
2.26.2