Em Thu, Feb 28, 2019 at 12:00:41PM +0300, Alexey Budankov escreveu: > > Implemented -f,--mmap-flush option that specifies threshold to postpone > and/or trigger the move of data from mmaped kernel buffers to a storage. > The option can be used to avoid capturing every single byte of data into > the stored trace. The default option value is 1.
Can you add something here explain more clearly what this means, and also on the tools/perf/Documentation/perf-record.txt file? Something like a paragraph explaining when is that there is a mmap flush normally, or rephrase what you wrote if you think you said that. - Arnaldo > $ tools/perf/perf record -f 1024 -e cycles -- matrix.gcc > $ tools/perf/perf record --aio -f 1024 -e cycles -- matrix.gcc > > Implemented sync param is the mean to force data move independently from > the threshold value. Despite a user provides flush value from the command > line, the tool needs capability to drain memory buffers, at least in the > end of the collection. > > Signed-off-by: Alexey Budankov <[email protected]> > --- > tools/perf/Documentation/perf-record.txt | 5 +++ > tools/perf/builtin-record.c | 53 +++++++++++++++++++++--- > tools/perf/perf.h | 1 + > tools/perf/util/evlist.c | 6 +-- > tools/perf/util/evlist.h | 3 +- > tools/perf/util/mmap.c | 4 +- > tools/perf/util/mmap.h | 3 +- > 7 files changed, 63 insertions(+), 12 deletions(-) > > diff --git a/tools/perf/Documentation/perf-record.txt > b/tools/perf/Documentation/perf-record.txt > index 8f0c2be34848..1727663382f1 100644 > --- a/tools/perf/Documentation/perf-record.txt > +++ b/tools/perf/Documentation/perf-record.txt > @@ -459,6 +459,11 @@ Set affinity mask of trace reading thread according to > the policy defined by 'mo > node - thread affinity mask is set to NUMA node cpu mask of the processed > mmap buffer > cpu - thread affinity mask is set to cpu of the processed mmap buffer > > +-f:: > +--mmap-flush=n:: > +Minimal number of bytes accumulated in mmaped kernel buffer that is flushed > to a storage (default: 1). > +Maximal allowed value is a quarter of mmaped kernel buffer size. > + > --all-kernel:: > Configure all used events to run in kernel space. > > diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c > index f3f7f3100336..61818cbce443 100644 > --- a/tools/perf/builtin-record.c > +++ b/tools/perf/builtin-record.c > @@ -334,6 +334,29 @@ static int record__aio_enabled(struct record *rec) > return rec->opts.nr_cblocks > 0; > } > > +#define MMAP_FLUSH_DEFAULT 1 > +static int record__mmap_flush_parse(const struct option *opt, > + const char *str, > + int unset) > +{ > + int mmap_len; > + struct record_opts *opts = (struct record_opts *)opt->value; > + > + if (unset) > + return 0; > + > + if (str) > + opts->mmap_flush = strtol(str, NULL, 0); > + if (!opts->mmap_flush) > + opts->mmap_flush = MMAP_FLUSH_DEFAULT; > + > + mmap_len = perf_evlist__mmap_size(opts->mmap_pages); > + if (opts->mmap_flush > mmap_len / 4) > + opts->mmap_flush = mmap_len / 4; > + > + return 0; > +} > + > static int process_synthesized_event(struct perf_tool *tool, > union perf_event *event, > struct perf_sample *sample __maybe_unused, > @@ -543,7 +566,8 @@ static int record__mmap_evlist(struct record *rec, > if (perf_evlist__mmap_ex(evlist, opts->mmap_pages, > opts->auxtrace_mmap_pages, > opts->auxtrace_snapshot_mode, > - opts->nr_cblocks, opts->affinity) < 0) { > + opts->nr_cblocks, opts->affinity, > + opts->mmap_flush) < 0) { > if (errno == EPERM) { > pr_err("Permission error mapping pages.\n" > "Consider increasing " > @@ -733,7 +757,7 @@ static void record__adjust_affinity(struct record *rec, > struct perf_mmap *map) > } > > static int record__mmap_read_evlist(struct record *rec, struct perf_evlist > *evlist, > - bool overwrite) > + bool overwrite, bool sync) > { > u64 bytes_written = rec->bytes_written; > int i; > @@ -756,12 +780,19 @@ static int record__mmap_read_evlist(struct record *rec, > struct perf_evlist *evli > off = record__aio_get_pos(trace_fd); > > for (i = 0; i < evlist->nr_mmaps; i++) { > + u64 flush = MMAP_FLUSH_DEFAULT; > struct perf_mmap *map = &maps[i]; > > if (map->base) { > record__adjust_affinity(rec, map); > + if (sync) { > + flush = map->flush; > + map->flush = MMAP_FLUSH_DEFAULT; > + } > if (!record__aio_enabled(rec)) { > if (perf_mmap__push(map, rec, record__pushfn) > != 0) { > + if (sync) > + map->flush = flush; > rc = -1; > goto out; > } > @@ -774,10 +805,14 @@ static int record__mmap_read_evlist(struct record *rec, > struct perf_evlist *evli > idx = record__aio_sync(map, false); > if (perf_mmap__aio_push(map, rec, idx, > record__aio_pushfn, &off) != 0) { > record__aio_set_pos(trace_fd, off); > + if (sync) > + map->flush = flush; > rc = -1; > goto out; > } > } > + if (sync) > + map->flush = flush; > } > > if (map->auxtrace_mmap.base && > !rec->opts.auxtrace_snapshot_mode && > @@ -803,15 +838,15 @@ static int record__mmap_read_evlist(struct record *rec, > struct perf_evlist *evli > return rc; > } > > -static int record__mmap_read_all(struct record *rec) > +static int record__mmap_read_all(struct record *rec, bool sync) > { > int err; > > - err = record__mmap_read_evlist(rec, rec->evlist, false); > + err = record__mmap_read_evlist(rec, rec->evlist, false, sync); > if (err) > return err; > > - return record__mmap_read_evlist(rec, rec->evlist, true); > + return record__mmap_read_evlist(rec, rec->evlist, true, sync); > } > > static void record__init_features(struct record *rec) > @@ -1310,7 +1345,7 @@ static int __cmd_record(struct record *rec, int argc, > const char **argv) > if (trigger_is_hit(&switch_output_trigger) || done || draining) > perf_evlist__toggle_bkw_mmap(rec->evlist, > BKW_MMAP_DATA_PENDING); > > - if (record__mmap_read_all(rec) < 0) { > + if (record__mmap_read_all(rec, false) < 0) { > trigger_error(&auxtrace_snapshot_trigger); > trigger_error(&switch_output_trigger); > err = -1; > @@ -1411,6 +1446,7 @@ static int __cmd_record(struct record *rec, int argc, > const char **argv) > record__synthesize_workload(rec, true); > > out_child: > + record__mmap_read_all(rec, true); > record__aio_mmap_read_sync(rec); > > if (forks) { > @@ -1813,6 +1849,7 @@ static struct record record = { > .uses_mmap = true, > .default_per_cpu = true, > }, > + .mmap_flush = MMAP_FLUSH_DEFAULT, > }, > .tool = { > .sample = process_sample_event, > @@ -1879,6 +1916,9 @@ static struct option __record_options[] = { > OPT_CALLBACK('m', "mmap-pages", &record.opts, "pages[,pages]", > "number of mmap data pages and AUX area tracing mmap > pages", > record__parse_mmap_pages), > + OPT_CALLBACK('f', "mmap-flush", &record.opts, "bytes", > + "Minimal number of bytes in mmap data pages that is > written to a storage (default: 1)", > + record__mmap_flush_parse), > OPT_BOOLEAN(0, "group", &record.opts.group, > "put the counters into a counter group"), > OPT_CALLBACK_NOOPT('g', NULL, &callchain_param, > @@ -2182,6 +2222,7 @@ int cmd_record(int argc, const char **argv) > pr_info("nr_cblocks: %d\n", rec->opts.nr_cblocks); > > pr_debug("affinity: %s\n", affinity_tags[rec->opts.affinity]); > + pr_debug("mmap flush: %d\n", rec->opts.mmap_flush); > > err = __cmd_record(&record, argc, argv); > out: > diff --git a/tools/perf/perf.h b/tools/perf/perf.h > index b120e547ddc7..7886cc9771cf 100644 > --- a/tools/perf/perf.h > +++ b/tools/perf/perf.h > @@ -85,6 +85,7 @@ struct record_opts { > u64 clockid_res_ns; > int nr_cblocks; > int affinity; > + int mmap_flush; > }; > > enum perf_affinity { > diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c > index 08cedb643ea6..937039faac59 100644 > --- a/tools/perf/util/evlist.c > +++ b/tools/perf/util/evlist.c > @@ -1022,7 +1022,7 @@ int perf_evlist__parse_mmap_pages(const struct option > *opt, const char *str, > */ > int perf_evlist__mmap_ex(struct perf_evlist *evlist, unsigned int pages, > unsigned int auxtrace_pages, > - bool auxtrace_overwrite, int nr_cblocks, int affinity) > + bool auxtrace_overwrite, int nr_cblocks, int affinity, > int flush) > { > struct perf_evsel *evsel; > const struct cpu_map *cpus = evlist->cpus; > @@ -1032,7 +1032,7 @@ int perf_evlist__mmap_ex(struct perf_evlist *evlist, > unsigned int pages, > * Its value is decided by evsel's write_backward. > * So &mp should not be passed through const pointer. > */ > - struct mmap_params mp = { .nr_cblocks = nr_cblocks, .affinity = > affinity }; > + struct mmap_params mp = { .nr_cblocks = nr_cblocks, .affinity = > affinity, .flush = flush }; > > if (!evlist->mmap) > evlist->mmap = perf_evlist__alloc_mmap(evlist, false); > @@ -1064,7 +1064,7 @@ int perf_evlist__mmap_ex(struct perf_evlist *evlist, > unsigned int pages, > > int perf_evlist__mmap(struct perf_evlist *evlist, unsigned int pages) > { > - return perf_evlist__mmap_ex(evlist, pages, 0, false, 0, > PERF_AFFINITY_SYS); > + return perf_evlist__mmap_ex(evlist, pages, 0, false, 0, > PERF_AFFINITY_SYS, 1); > } > > int perf_evlist__create_maps(struct perf_evlist *evlist, struct target > *target) > diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h > index 744906dd4887..edf18811e39f 100644 > --- a/tools/perf/util/evlist.h > +++ b/tools/perf/util/evlist.h > @@ -165,7 +165,8 @@ unsigned long perf_event_mlock_kb_in_pages(void); > > int perf_evlist__mmap_ex(struct perf_evlist *evlist, unsigned int pages, > unsigned int auxtrace_pages, > - bool auxtrace_overwrite, int nr_cblocks, int affinity); > + bool auxtrace_overwrite, int nr_cblocks, > + int affinity, int flush); > int perf_evlist__mmap(struct perf_evlist *evlist, unsigned int pages); > void perf_evlist__munmap(struct perf_evlist *evlist); > > diff --git a/tools/perf/util/mmap.c b/tools/perf/util/mmap.c > index cdc7740fc181..ef3d79b2c90b 100644 > --- a/tools/perf/util/mmap.c > +++ b/tools/perf/util/mmap.c > @@ -440,6 +440,8 @@ int perf_mmap__mmap(struct perf_mmap *map, struct > mmap_params *mp, int fd, int c > > perf_mmap__setup_affinity_mask(map, mp); > > + map->flush = mp->flush; > + > if (auxtrace_mmap__mmap(&map->auxtrace_mmap, > &mp->auxtrace_mp, map->base, fd)) > return -1; > @@ -492,7 +494,7 @@ static int __perf_mmap__read_init(struct perf_mmap *md) > md->start = md->overwrite ? head : old; > md->end = md->overwrite ? old : head; > > - if (md->start == md->end) > + if ((md->end - md->start) < md->flush) > return -EAGAIN; > > size = md->end - md->start; > diff --git a/tools/perf/util/mmap.h b/tools/perf/util/mmap.h > index e566c19b242b..b82f8c2d55c4 100644 > --- a/tools/perf/util/mmap.h > +++ b/tools/perf/util/mmap.h > @@ -39,6 +39,7 @@ struct perf_mmap { > } aio; > #endif > cpu_set_t affinity_mask; > + u64 flush; > }; > > /* > @@ -70,7 +71,7 @@ enum bkw_mmap_state { > }; > > struct mmap_params { > - int prot, mask, nr_cblocks, affinity; > + int prot, mask, nr_cblocks, affinity, flush; > struct auxtrace_mmap_params auxtrace_mp; > }; -- - Arnaldo
