From d3944f0ed4e4039201b160fc11004abaa2ca5385 Mon Sep 17 00:00:00 2001 From: Ian Rogers Date: Fri, 26 May 2023 20:43:21 -0700 Subject: [PATCH] perf inject: Lazily allocate event_copy The event_copy is 64kb (PERF_SAMPLE_SIZE_MAX) and stack allocated in struct perf_inject. It is used for aux events that may not exist in a file. Make the array allocation lazy to cut down on the stack usage. Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ingo Molnar Cc: Jiri Olsa Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Link: https://lore.kernel.org/r/20230527034324.2597593-4-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-inject.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c index d19a1b862306..2023b7a0daa6 100644 --- a/tools/perf/builtin-inject.c +++ b/tools/perf/builtin-inject.c @@ -122,7 +122,7 @@ struct perf_inject { u64 aux_id; struct list_head samples; struct itrace_synth_opts itrace_synth_opts; - char event_copy[PERF_SAMPLE_MAX_SIZE]; + char *event_copy; struct perf_file_section secs[HEADER_FEAT_BITS]; struct guest_session guest_session; struct strlist *known_build_ids; @@ -320,8 +320,14 @@ perf_inject__cut_auxtrace_sample(struct perf_inject *inject, { size_t sz1 = sample->aux_sample.data - (void *)event; size_t sz2 = event->header.size - sample->aux_sample.size - sz1; - union perf_event *ev = (union perf_event *)inject->event_copy; + union perf_event *ev; + if (inject->event_copy == NULL) { + inject->event_copy = malloc(PERF_SAMPLE_MAX_SIZE); + if (!inject->event_copy) + return ERR_PTR(-ENOMEM); + } + ev = (union perf_event *)inject->event_copy; if (sz1 > event->header.size || sz2 > event->header.size || sz1 + sz2 > event->header.size || sz1 < sizeof(struct perf_event_header) + sizeof(u64)) @@ -357,8 +363,11 @@ static int perf_event__repipe_sample(struct perf_tool *tool, build_id__mark_dso_hit(tool, event, sample, evsel, machine); - if (inject->itrace_synth_opts.set && sample->aux_sample.size) + if (inject->itrace_synth_opts.set && sample->aux_sample.size) { event = perf_inject__cut_auxtrace_sample(inject, event, sample); + if (IS_ERR(event)) + return PTR_ERR(event); + } return perf_event__repipe_synth(tool, event); } @@ -2391,5 +2400,6 @@ out_close_output: if (!inject.in_place_update) perf_data__close(&inject.output); free(inject.itrace_synth_opts.vm_tm_corr_args); + free(inject.event_copy); return ret; }