This is a note to let you know that I've just added the patch titled
perf inject: Fix leader sampling inserting additional samples
to the 5.15-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-inject-fix-leader-sampling-inserting-additional.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 4204dd342041d4d6f9d9950685b6de61fc0b46d3
Author: Ian Rogers <irogers@xxxxxxxxxx>
Date: Mon Jul 29 15:06:20 2024 -0700
perf inject: Fix leader sampling inserting additional samples
[ Upstream commit 79bcd34e0f3da39fda841406ccc957405e724852 ]
The processing of leader samples would turn an individual sample with
a group of read values into multiple samples. 'perf inject' would pass
through the additional samples increasing the output data file size:
$ perf record -g -e "{instructions,cycles}:S" -o perf.orig.data true
$ perf script -D -i perf.orig.data | sed -e 's/perf.orig.data/perf.data/g' > orig.txt
$ perf inject -i perf.orig.data -o perf.new.data
$ perf script -D -i perf.new.data | sed -e 's/perf.new.data/perf.data/g' > new.txt
$ diff -u orig.txt new.txt
--- orig.txt 2024-07-29 14:29:40.606576769 -0700
+++ new.txt 2024-07-29 14:30:04.142737434 -0700
...
-0xc550@xxxxxxxxx [0x30]: event: 3
+0xc550@xxxxxxxxx [0xd0]: event: 9
+.
+. ... raw event: size 208 bytes
+. 0000: 09 00 00 00 01 00 d0 00 fc 72 01 86 ff ff ff ff .........r......
+. 0010: 74 7d 2c 00 74 7d 2c 00 fb c3 79 f9 ba d5 05 00 t},.t},...y.....
+. 0020: e6 cb 1a 00 00 00 00 00 01 00 00 00 00 00 00 00 ................
+. 0030: 02 00 00 00 00 00 00 00 76 01 00 00 00 00 00 00 ........v.......
+. 0040: e6 cb 1a 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
+. 0050: 62 18 00 00 00 00 00 00 f6 cb 1a 00 00 00 00 00 b...............
+. 0060: 00 00 00 00 00 00 00 00 0c 00 00 00 00 00 00 00 ................
+. 0070: 80 ff ff ff ff ff ff ff fc 72 01 86 ff ff ff ff .........r......
+. 0080: f3 0e 6e 85 ff ff ff ff 0c cb 7f 85 ff ff ff ff ..n.............
+. 0090: bc f2 87 85 ff ff ff ff 44 af 7f 85 ff ff ff ff ........D.......
+. 00a0: bd be 7f 85 ff ff ff ff 26 d0 7f 85 ff ff ff ff ........&.......
+. 00b0: 6d a4 ff 85 ff ff ff ff ea 00 20 86 ff ff ff ff m......... .....
+. 00c0: 00 fe ff ff ff ff ff ff 57 14 4f 43 fc 7e 00 00 ........W.OC.~..
+
+1642373909693435 0xc550 [0xd0]: PERF_RECORD_SAMPLE(IP, 0x1): 2915700/2915700: 0xffffffff860172fc period: 1 addr: 0
+... FP chain: nr:12
+..... 0: ffffffffffffff80
+..... 1: ffffffff860172fc
+..... 2: ffffffff856e0ef3
+..... 3: ffffffff857fcb0c
+..... 4: ffffffff8587f2bc
+..... 5: ffffffff857faf44
+..... 6: ffffffff857fbebd
+..... 7: ffffffff857fd026
+..... 8: ffffffff85ffa46d
+..... 9: ffffffff862000ea
+..... 10: fffffffffffffe00
+..... 11: 00007efc434f1457
+... sample_read:
+.... group nr 2
+..... id 00000000001acbe6, value 0000000000000176, lost 0
+..... id 00000000001acbf6, value 0000000000001862, lost 0
+
+0xc620@xxxxxxxxx [0x30]: event: 3
...
This behavior is incorrect as in the case above 'perf inject' should
have done nothing. Fix this behavior by disabling separating samples
for a tool that requests it. Only request this for `perf inject` so as
to not affect other perf tools. With the patch and the test above
there are no differences between the orig.txt and new.txt.
Fixes: e4caec0d1af3d608 ("perf evsel: Add PERF_SAMPLE_READ sample related processing")
Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
Acked-by: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20240729220620.2957754-1-irogers@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c
index 8e7a65a8d86ed..2e9d81a16133c 100644
--- a/tools/perf/builtin-inject.c
+++ b/tools/perf/builtin-inject.c
@@ -910,6 +910,7 @@ int cmd_inject(int argc, const char **argv)
.feature = perf_event__repipe_op2_synth,
.compressed = perf_event__repipe_op4_synth,
.auxtrace = perf_event__repipe_auxtrace,
+ .dont_split_sample_group = true,
},
.input_name = "-",
.samples = LIST_HEAD_INIT(inject.samples),
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 7ba9dd1402ed2..60c44cb33d4a2 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -1453,6 +1453,9 @@ static int deliver_sample_group(struct evlist *evlist,
int ret = -EINVAL;
struct sample_read_value *v = sample->read.group.values;
+ if (tool->dont_split_sample_group)
+ return deliver_sample_value(evlist, tool, event, sample, v, machine);
+
sample_read_group__for_each(v, sample->read.group.nr, read_format) {
ret = deliver_sample_value(evlist, tool, event, sample, v,
machine);
diff --git a/tools/perf/util/tool.h b/tools/perf/util/tool.h
index bbbc0dcd461ff..504bed227d1e1 100644
--- a/tools/perf/util/tool.h
+++ b/tools/perf/util/tool.h
@@ -82,6 +82,7 @@ struct perf_tool {
bool namespace_events;
bool cgroup_events;
bool no_warn;
+ bool dont_split_sample_group;
enum show_feature_header show_feat_hdr;
};
