Patch "perf test: Add 'sqrtloop' test workload" has been added to the 6.1-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    perf test: Add 'sqrtloop' test workload

to the 6.1-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     perf-test-add-sqrtloop-test-workload.patch
and it can be found in the queue-6.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit c02b308dcf7af8fe53112ab20657f556e8e5e01a
Author: Namhyung Kim <namhyung@xxxxxxxxxx>
Date:   Wed Nov 16 15:38:49 2022 -0800

    perf test: Add 'sqrtloop' test workload
    
    [ Upstream commit 39281709a6e2301ac4c6ac7015c7793392ca2dfe ]
    
    The sqrtloop creates a child process to run an infinite loop calling
    sqrt() with rand().  This is needed for ARM SPE fork test.
    
      $ perf test -w sqrtloop
    
    It can take an optional argument to specify how long it will run in
    seconds (default: 1).
    
    Committer notes:
    
    Explicitely ignored the sqrt() return to fix the build on systems where
    the compiler complains it isn't being used.
    
    And added a sqrtloop specific CFLAGS to disable optimizations to make
    this a bit more robust wrt dead code elimination.
    
    Doing that a -U_FORTIFY_SOURCE needs to be added, as -O0 is incompatible
    with it.
    
    Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
    Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
    Cc: Athira Jajeev <atrajeev@xxxxxxxxxxxxxxxxxx>
    Cc: German Gomez <german.gomez@xxxxxxx>
    Cc: Ian Rogers <irogers@xxxxxxxxxx>
    Cc: Ingo Molnar <mingo@xxxxxxxxxx>
    Cc: James Clark <james.clark@xxxxxxx>
    Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
    Cc: Leo Yan <leo.yan@xxxxxxxxxx>
    Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
    Cc: Zhengjun Xing <zhengjun.xing@xxxxxxxxxxxxxxx>
    Link: https://lore.kernel.org/r/20221116233854.1596378-8-namhyung@xxxxxxxxxx
    Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
    Stable-dep-of: 256ef072b384 ("perf tests: Make "test data symbol" more robust on Neoverse N1")
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c
index 0ed5ac452f6ee..9acb7a93eeb97 100644
--- a/tools/perf/tests/builtin-test.c
+++ b/tools/perf/tests/builtin-test.c
@@ -122,6 +122,7 @@ static struct test_workload *workloads[] = {
 	&workload__noploop,
 	&workload__thloop,
 	&workload__leafloop,
+	&workload__sqrtloop,
 };
 
 static int num_subtests(const struct test_suite *t)
diff --git a/tools/perf/tests/tests.h b/tools/perf/tests/tests.h
index 86804dd6452b7..18c40319e67c7 100644
--- a/tools/perf/tests/tests.h
+++ b/tools/perf/tests/tests.h
@@ -203,5 +203,6 @@ struct test_workload workload__##work = {	\
 DECLARE_WORKLOAD(noploop);
 DECLARE_WORKLOAD(thloop);
 DECLARE_WORKLOAD(leafloop);
+DECLARE_WORKLOAD(sqrtloop);
 
 #endif /* TESTS_H */
diff --git a/tools/perf/tests/workloads/Build b/tools/perf/tests/workloads/Build
index 03dc675a4a7c8..2312a338f01c0 100644
--- a/tools/perf/tests/workloads/Build
+++ b/tools/perf/tests/workloads/Build
@@ -3,5 +3,7 @@
 perf-y += noploop.o
 perf-y += thloop.o
 perf-y += leafloop.o
+perf-y += sqrtloop.o
 
+CFLAGS_sqrtloop.o         = -g -O0 -fno-inline -U_FORTIFY_SOURCE
 CFLAGS_leafloop.o         = -g -O0 -fno-inline -fno-omit-frame-pointer -U_FORTIFY_SOURCE
diff --git a/tools/perf/tests/workloads/sqrtloop.c b/tools/perf/tests/workloads/sqrtloop.c
new file mode 100644
index 0000000000000..ccc94c6a6676a
--- /dev/null
+++ b/tools/perf/tests/workloads/sqrtloop.c
@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <math.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <linux/compiler.h>
+#include <sys/wait.h>
+#include "../tests.h"
+
+static volatile sig_atomic_t done;
+
+static void sighandler(int sig __maybe_unused)
+{
+	done = 1;
+}
+
+static int __sqrtloop(int sec)
+{
+	signal(SIGALRM, sighandler);
+	alarm(sec);
+
+	while (!done)
+		(void)sqrt(rand());
+	return 0;
+}
+
+static int sqrtloop(int argc, const char **argv)
+{
+	int sec = 1;
+
+	if (argc > 0)
+		sec = atoi(argv[0]);
+
+	switch (fork()) {
+	case 0:
+		return __sqrtloop(sec);
+	case -1:
+		return -1;
+	default:
+		wait(NULL);
+	}
+	return 0;
+}
+
+DEFINE_WORKLOAD(sqrtloop);