Patch "perf kmem: Support legacy tracepoints" 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 kmem: Support legacy tracepoints

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-kmem-support-legacy-tracepoints.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 2204e7dd6595ecb466904fd55d84dd54ffa61787
Author: Leo Yan <leo.yan@xxxxxxxxxx>
Date:   Sun Jan 8 14:23:59 2023 +0800

    perf kmem: Support legacy tracepoints
    
    [ Upstream commit b3719108ae60169eda5c941ca5e1be1faa371c57 ]
    
    Commit 11e9734bcb6a7361 ("mm/slab_common: unify NUMA and UMA version of
    tracepoints") removed tracepoints 'kmalloc_node' and
    'kmem_cache_alloc_node', we need to consider the tool should be backward
    compatible.
    
    If it detect the tracepoint "kmem:kmalloc_node", this patch enables the
    legacy tracepoints, otherwise, it will ignore them.
    
    Fixes: 11e9734bcb6a7361 ("mm/slab_common: unify NUMA and UMA version of tracepoints")
    Reported-by: Ravi Bangoria <ravi.bangoria@xxxxxxx>
    Reviewed-by: James Clark <james.clark@xxxxxxx>
    Signed-off-by: Leo Yan <leo.yan@xxxxxxxxxx>
    Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
    Cc: Hyeonggon Yoo <42.hyeyoo@xxxxxxxxx>
    Cc: Ingo Molnar <mingo@xxxxxxxxxx>
    Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
    Cc: Mark Rutland <mark.rutland@xxxxxxx>
    Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
    Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
    Cc: Vlastimil Babka <vbabka@xxxxxxx>
    Link: https://lore.kernel.org/r/20230108062400.250690-1-leo.yan@xxxxxxxxxx
    Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/tools/perf/builtin-kmem.c b/tools/perf/builtin-kmem.c
index ebfab2ca1702..63c759edb8bc 100644
--- a/tools/perf/builtin-kmem.c
+++ b/tools/perf/builtin-kmem.c
@@ -1823,6 +1823,19 @@ static int parse_line_opt(const struct option *opt __maybe_unused,
 	return 0;
 }
 
+static bool slab_legacy_tp_is_exposed(void)
+{
+	/*
+	 * The tracepoints "kmem:kmalloc_node" and
+	 * "kmem:kmem_cache_alloc_node" have been removed on the latest
+	 * kernel, if the tracepoint "kmem:kmalloc_node" is existed it
+	 * means the tool is running on an old kernel, we need to
+	 * rollback to support these legacy tracepoints.
+	 */
+	return IS_ERR(trace_event__tp_format("kmem", "kmalloc_node")) ?
+		false : true;
+}
+
 static int __cmd_record(int argc, const char **argv)
 {
 	const char * const record_args[] = {
@@ -1830,22 +1843,28 @@ static int __cmd_record(int argc, const char **argv)
 	};
 	const char * const slab_events[] = {
 	"-e", "kmem:kmalloc",
-	"-e", "kmem:kmalloc_node",
 	"-e", "kmem:kfree",
 	"-e", "kmem:kmem_cache_alloc",
-	"-e", "kmem:kmem_cache_alloc_node",
 	"-e", "kmem:kmem_cache_free",
 	};
+	const char * const slab_legacy_events[] = {
+	"-e", "kmem:kmalloc_node",
+	"-e", "kmem:kmem_cache_alloc_node",
+	};
 	const char * const page_events[] = {
 	"-e", "kmem:mm_page_alloc",
 	"-e", "kmem:mm_page_free",
 	};
 	unsigned int rec_argc, i, j;
 	const char **rec_argv;
+	unsigned int slab_legacy_tp_exposed = slab_legacy_tp_is_exposed();
 
 	rec_argc = ARRAY_SIZE(record_args) + argc - 1;
-	if (kmem_slab)
+	if (kmem_slab) {
 		rec_argc += ARRAY_SIZE(slab_events);
+		if (slab_legacy_tp_exposed)
+			rec_argc += ARRAY_SIZE(slab_legacy_events);
+	}
 	if (kmem_page)
 		rec_argc += ARRAY_SIZE(page_events) + 1; /* for -g */
 
@@ -1860,6 +1879,10 @@ static int __cmd_record(int argc, const char **argv)
 	if (kmem_slab) {
 		for (j = 0; j < ARRAY_SIZE(slab_events); j++, i++)
 			rec_argv[i] = strdup(slab_events[j]);
+		if (slab_legacy_tp_exposed) {
+			for (j = 0; j < ARRAY_SIZE(slab_legacy_events); j++, i++)
+				rec_argv[i] = strdup(slab_legacy_events[j]);
+		}
 	}
 	if (kmem_page) {
 		rec_argv[i++] = strdup("-g");