Messages in this thread | | | Date | Wed, 21 Sep 2022 14:50:23 +0100 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH v2 2/2] perf record: Save DSO build-ID for synthesizing |
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Em Tue, Sep 20, 2022 at 03:28:22PM -0700, Namhyung Kim escreveu: > When synthesizing MMAP2 with build-id, it'd read the same file repeatedly as > it has no idea if it's done already. Maintain a dsos to check that and skip > the file access if possible. > > Signed-off-by: Namhyung Kim <namhyung@kernel.org> > --- > v2 change) > * Remove perf_event__synthesize_{start,stop} and use machine->dsos (Adrian)
Will wait till I merge perf/urgent into perf/core so that this applies.
- Arnaldo
> tools/perf/util/synthetic-events.c | 25 ++++++++++++++++++++++--- > 1 file changed, 22 insertions(+), 3 deletions(-) > > diff --git a/tools/perf/util/synthetic-events.c b/tools/perf/util/synthetic-events.c > index 289ea17ac5f7..cccd293b5312 100644 > --- a/tools/perf/util/synthetic-events.c > +++ b/tools/perf/util/synthetic-events.c > @@ -364,11 +364,14 @@ static bool read_proc_maps_line(struct io *io, __u64 *start, __u64 *end, > } > > static void perf_record_mmap2__read_build_id(struct perf_record_mmap2 *event, > + struct machine *machine, > bool is_kernel) > { > struct build_id bid; > struct nsinfo *nsi; > struct nscookie nc; > + struct dso *dso = NULL; > + struct dso_id id; > int rc; > > if (is_kernel) { > @@ -376,6 +379,18 @@ static void perf_record_mmap2__read_build_id(struct perf_record_mmap2 *event, > goto out; > } > > + id.maj = event->maj; > + id.min = event->min; > + id.ino = event->ino; > + id.ino_generation = event->ino_generation; > + > + dso = dsos__findnew_id(&machine->dsos, event->filename, &id); > + if (dso && dso->has_build_id) { > + bid = dso->bid; > + rc = 0; > + goto out; > + } > + > nsi = nsinfo__new(event->pid); > nsinfo__mountns_enter(nsi, &nc); > > @@ -391,12 +406,16 @@ static void perf_record_mmap2__read_build_id(struct perf_record_mmap2 *event, > event->header.misc |= PERF_RECORD_MISC_MMAP_BUILD_ID; > event->__reserved_1 = 0; > event->__reserved_2 = 0; > + > + if (dso && !dso->has_build_id) > + dso__set_build_id(dso, &bid); > } else { > if (event->filename[0] == '/') { > pr_debug2("Failed to read build ID for %s\n", > event->filename); > } > } > + dso__put(dso); > } > > int perf_event__synthesize_mmap_events(struct perf_tool *tool, > @@ -507,7 +526,7 @@ int perf_event__synthesize_mmap_events(struct perf_tool *tool, > event->mmap2.tid = pid; > > if (symbol_conf.buildid_mmap2) > - perf_record_mmap2__read_build_id(&event->mmap2, false); > + perf_record_mmap2__read_build_id(&event->mmap2, machine, false); > > if (perf_tool__process_synth_event(tool, event, machine, process) != 0) { > rc = -1; > @@ -690,7 +709,7 @@ int perf_event__synthesize_modules(struct perf_tool *tool, perf_event__handler_t > memcpy(event->mmap2.filename, pos->dso->long_name, > pos->dso->long_name_len + 1); > > - perf_record_mmap2__read_build_id(&event->mmap2, false); > + perf_record_mmap2__read_build_id(&event->mmap2, machine, false); > } else { > size = PERF_ALIGN(pos->dso->long_name_len + 1, sizeof(u64)); > event->mmap.header.type = PERF_RECORD_MMAP; > @@ -1126,7 +1145,7 @@ static int __perf_event__synthesize_kernel_mmap(struct perf_tool *tool, > event->mmap2.len = map->end - event->mmap.start; > event->mmap2.pid = machine->pid; > > - perf_record_mmap2__read_build_id(&event->mmap2, true); > + perf_record_mmap2__read_build_id(&event->mmap2, machine, true); > } else { > size = snprintf(event->mmap.filename, sizeof(event->mmap.filename), > "%s%s", machine->mmap_name, kmap->ref_reloc_sym->name) + 1; > -- > 2.37.3.968.ga6b4b080e4-goog
--
- Arnaldo
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