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

From: Davidlohr Bueso <dave@stgolabs.net>
Date: 2021-08-06 01:33:42
Also in: lkml
Subsystem: futex subsystem, performance events subsystem, the rest · Maintainers: Thomas Gleixner, Ingo Molnar, Peter Zijlstra, Arnaldo Carvalho de Melo, Namhyung Kim, Linus Torvalds

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 <redacted>
---
 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

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