Messages in this thread | | | Date | Tue, 12 Feb 2019 14:08:11 +0100 | From | Jiri Olsa <> | Subject | Re: [PATCH v2 2/4] perf record: implement -z=<level> and --mmap-flush=<thres> options |
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On Mon, Feb 11, 2019 at 11:22:38PM +0300, Alexey Budankov wrote:
SNIP
> static int process_synthesized_event(struct perf_tool *tool, > union perf_event *event, > struct perf_sample *sample __maybe_unused, > @@ -543,7 +574,8 @@ 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 " > @@ -734,7 +766,7 @@ 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; > @@ -757,12 +789,19 @@ 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; > } > @@ -775,10 +814,14 @@ 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; > }
what's 'flush' and 'sync' for? also the above handling seems confusing, why would you set it temporarily for default value if you let it set by user command line option?
SNIP
> -static void perf_mmap__aio_munmap(struct perf_mmap *map __maybe_unused) > +static void perf_mmap__aio_munmap_blocks(struct perf_mmap *map __maybe_unused) > { > } > #endif > @@ -444,6 +468,8 @@ int perf_mmap__mmap(struct perf_mmap *map, struct mmap_params *mp, int fd, int c > &mp->auxtrace_mp, map->base, fd)) > return -1; > > + map->flush = mp->flush; > + > return perf_mmap__aio_mmap(map, mp); > } > > @@ -492,7 +518,7 @@ 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;
we need document and explain this change in changelog in separate patch
thanks, jirka
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