Messages in this thread Patch in this message | | | From | Jiri Olsa <> | Subject | [PATCH 22/36] libperf: Centralize map refcnt setting | Date | Mon, 7 Oct 2019 14:53:30 +0200 |
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Currently when new map is mmaps we set its refcnt to 2 in perf_evlist_mmap_ops::mmap callback.
Every mmap is given refcnt set to 2 when it's first mmaped: - 1 for current user, which will be taken out by call to perf_evlist__munmap_filtered, where we find out there's no more data comming from kernel to this mmap - 1 for drain code where in perf_mmap__consume the mmap is released if it is empty
Moving this common setup into libperf generic code before mmap callback is called.
Link: http://lkml.kernel.org/n/tip-3us74tjjz258bgk2pavjaq59@git.kernel.org Signed-off-by: Jiri Olsa <jolsa@kernel.org> --- tools/perf/lib/evlist.c | 30 +++++++++++++++--------------- tools/perf/util/mmap.c | 15 --------------- 2 files changed, 15 insertions(+), 30 deletions(-)
diff --git a/tools/perf/lib/evlist.c b/tools/perf/lib/evlist.c index b69722627779..f9a802d2ceb5 100644 --- a/tools/perf/lib/evlist.c +++ b/tools/perf/lib/evlist.c @@ -362,21 +362,6 @@ static int perf_evlist__mmap_cb_mmap(struct perf_mmap *map, struct perf_mmap_param *mp, int output, int cpu) { - /* - * The last one will be done at perf_mmap__consume(), so that we - * make sure we don't prevent tools from consuming every last event in - * the ring buffer. - * - * I.e. we can get the POLLHUP meaning that the fd doesn't exist - * anymore, but the last events for it are still in the ring buffer, - * waiting to be consumed. - * - * Tools can chose to ignore this at their own discretion, but the - * evlist layer can't just drop it when filtering events in - * perf_evlist__filter_pollfd(). - */ - refcount_set(&map->refcnt, 2); - return perf_mmap__mmap(map, mp, output, cpu); } @@ -418,6 +403,21 @@ mmap_per_evsel(struct perf_evlist *evlist, struct perf_evlist_mmap_ops *ops, if (*output == -1) { *output = fd; + /* + * The last one will be done at perf_mmap__consume(), so that we + * make sure we don't prevent tools from consuming every last event in + * the ring buffer. + * + * I.e. we can get the POLLHUP meaning that the fd doesn't exist + * anymore, but the last events for it are still in the ring buffer, + * waiting to be consumed. + * + * Tools can chose to ignore this at their own discretion, but the + * evlist layer can't just drop it when filtering events in + * perf_evlist__filter_pollfd(). + */ + refcount_set(&map->refcnt, 2); + if (ops->mmap(map, mp, *output, evlist_cpu) < 0) return -1; } else { diff --git a/tools/perf/util/mmap.c b/tools/perf/util/mmap.c index 2a8bf0ab861c..063d1b93c53d 100644 --- a/tools/perf/util/mmap.c +++ b/tools/perf/util/mmap.c @@ -243,21 +243,6 @@ static void perf_mmap__setup_affinity_mask(struct mmap *map, struct mmap_params int mmap__mmap(struct mmap *map, struct mmap_params *mp, int fd, int cpu) { - /* - * The last one will be done at perf_mmap__consume(), so that we - * make sure we don't prevent tools from consuming every last event in - * the ring buffer. - * - * I.e. we can get the POLLHUP meaning that the fd doesn't exist - * anymore, but the last events for it are still in the ring buffer, - * waiting to be consumed. - * - * Tools can chose to ignore this at their own discretion, but the - * evlist layer can't just drop it when filtering events in - * perf_evlist__filter_pollfd(). - */ - refcount_set(&map->core.refcnt, 2); - if (perf_mmap__mmap(&map->core, &mp->core, fd, cpu)) { pr_debug2("failed to mmap perf event ring buffer, error %d\n", errno); -- 2.21.0
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