Patch "perf test: Make test_arm_callgraph_fp.sh more robust" 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: Make test_arm_callgraph_fp.sh more robust

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-make-test_arm_callgraph_fp.sh-more-robust.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 be4520d4c5deb5001c6ef37a5ce93d21872eda25
Author: James Clark <james.clark@xxxxxxx>
Date:   Wed Jun 12 15:03:14 2024 +0100

    perf test: Make test_arm_callgraph_fp.sh more robust
    
    [ Upstream commit ff16aeb9b83441b8458d4235496cf320189a0c60 ]
    
    The 2 second sleep can cause the test to fail on very slow network file
    systems because Perf ends up being killed before it finishes starting
    up.
    
    Fix it by making the leafloop workload end after a fixed time like the
    other workloads so there is no need to kill it after 2 seconds.
    
    Also remove the 1 second start sampling delay because it is similarly
    fragile. Instead, search through all samples for a matching one, rather
    than just checking the first sample and hoping it's in the right place.
    
    Fixes: cd6382d82752 ("perf test arm64: Test unwinding using fame-pointer (fp) mode")
    Signed-off-by: James Clark <james.clark@xxxxxxx>
    Acked-by: Namhyung Kim <namhyung@xxxxxxxxxx>
    Cc: German Gomez <german.gomez@xxxxxxx>
    Cc: Spoorthy S <spoorts2@xxxxxxxxxx>
    Cc: Kajol Jain <kjain@xxxxxxxxxxxxx>
    Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
    Link: https://lore.kernel.org/r/20240612140316.3006660-1-james.clark@xxxxxxx
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/tools/perf/tests/shell/test_arm_callgraph_fp.sh b/tools/perf/tests/shell/test_arm_callgraph_fp.sh
index 66dfdfdad553f..60cd35c73e47d 100755
--- a/tools/perf/tests/shell/test_arm_callgraph_fp.sh
+++ b/tools/perf/tests/shell/test_arm_callgraph_fp.sh
@@ -14,28 +14,21 @@ cleanup_files()
 
 trap cleanup_files EXIT TERM INT
 
-# Add a 1 second delay to skip samples that are not in the leaf() function
 # shellcheck disable=SC2086
-perf record -o "$PERF_DATA" --call-graph fp -e cycles//u -D 1000 --user-callchains -- $TEST_PROGRAM 2> /dev/null &
-PID=$!
+perf record -o "$PERF_DATA" --call-graph fp -e cycles//u --user-callchains -- $TEST_PROGRAM
 
-echo " + Recording (PID=$PID)..."
-sleep 2
-echo " + Stopping perf-record..."
-
-kill $PID
-wait $PID
+# Try opening the file so any immediate errors are visible in the log
+perf script -i "$PERF_DATA" -F comm,ip,sym | head -n4
 
-# expected perf-script output:
+# expected perf-script output if 'leaf' has been inserted correctly:
 #
-# program
+# perf
 # 	728 leaf
 # 	753 parent
 # 	76c leafloop
-# ...
+# ... remaining stack to main() ...
 
-perf script -i "$PERF_DATA" -F comm,ip,sym | head -n4
-perf script -i "$PERF_DATA" -F comm,ip,sym | head -n4 | \
-	awk '{ if ($2 != "") sym[i++] = $2 } END { if (sym[0] != "leaf" ||
-						       sym[1] != "parent" ||
-						       sym[2] != "leafloop") exit 1 }'
+# Each frame is separated by a tab, some spaces and an address
+SEP="[[:space:]]+ [[:xdigit:]]+"
+perf script -i "$PERF_DATA" -F comm,ip,sym | tr '\n' ' ' | \
+	grep -E -q "perf $SEP leaf $SEP parent $SEP leafloop"
diff --git a/tools/perf/tests/workloads/leafloop.c b/tools/perf/tests/workloads/leafloop.c
index 1bf5cc97649b0..f7561767e32cd 100644
--- a/tools/perf/tests/workloads/leafloop.c
+++ b/tools/perf/tests/workloads/leafloop.c
@@ -1,6 +1,8 @@
 /* SPDX-License-Identifier: GPL-2.0 */
+#include <signal.h>
 #include <stdlib.h>
 #include <linux/compiler.h>
+#include <unistd.h>
 #include "../tests.h"
 
 /* We want to check these symbols in perf script */
@@ -8,10 +10,16 @@ noinline void leaf(volatile int b);
 noinline void parent(volatile int b);
 
 static volatile int a;
+static volatile sig_atomic_t done;
+
+static void sighandler(int sig __maybe_unused)
+{
+	done = 1;
+}
 
 noinline void leaf(volatile int b)
 {
-	for (;;)
+	while (!done)
 		a += b;
 }
 
@@ -22,12 +30,16 @@ noinline void parent(volatile int b)
 
 static int leafloop(int argc, const char **argv)
 {
-	int c = 1;
+	int sec = 1;
 
 	if (argc > 0)
-		c = atoi(argv[0]);
+		sec = atoi(argv[0]);
+
+	signal(SIGINT, sighandler);
+	signal(SIGALRM, sighandler);
+	alarm(sec);
 
-	parent(c);
+	parent(sec);
 	return 0;
 }