6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Ian Rogers irogers@google.com
[ 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@perf.data [0x30]: event: 3 +0xc550@perf.data [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@perf.data [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@google.com Acked-by: Namhyung Kim namhyung@kernel.org Cc: Adrian Hunter adrian.hunter@intel.com Cc: Alexander Shishkin alexander.shishkin@linux.intel.com Cc: Andi Kleen ak@linux.intel.com Cc: Ingo Molnar mingo@redhat.com Cc: Jiri Olsa jolsa@kernel.org Cc: Jiri Olsa jolsa@redhat.com Cc: Kan Liang kan.liang@linux.intel.com Cc: Mark Rutland mark.rutland@arm.com Cc: Peter Zijlstra peterz@infradead.org Link: https://lore.kernel.org/r/20240729220620.2957754-1-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- tools/perf/builtin-inject.c | 1 + tools/perf/util/session.c | 3 +++ tools/perf/util/tool.h | 1 + 3 files changed, 5 insertions(+)
diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c index eb3ef5c24b662..8aba056654679 100644 --- a/tools/perf/builtin-inject.c +++ b/tools/perf/builtin-inject.c @@ -2200,6 +2200,7 @@ int cmd_inject(int argc, const char **argv) .finished_init = 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 c6afba7ab1a51..277b2cbd51861 100644 --- a/tools/perf/util/session.c +++ b/tools/perf/util/session.c @@ -1500,6 +1500,9 @@ 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 c957fb849ac63..62bbc9cec151b 100644 --- a/tools/perf/util/tool.h +++ b/tools/perf/util/tool.h @@ -85,6 +85,7 @@ struct perf_tool { bool namespace_events; bool cgroup_events; bool no_warn; + bool dont_split_sample_group; enum show_feature_header show_feat_hdr; };