The following commit has been merged into the perf/core branch of tip: Commit-ID: b5911e7ac28cb34f21b7380915ce98518078f114 Gitweb: https://git.kernel.org/tip/b5911e7ac28cb34f21b7380915ce98518078f114 Author: Jiri Olsa <jo...@kernel.org> AuthorDate: Mon, 07 Oct 2019 14:53:25 +02:00 Committer: Arnaldo Carvalho de Melo <a...@redhat.com> CommitterDate: Thu, 10 Oct 2019 12:22:21 -03:00
libperf: Introduce perf_evlist_mmap_ops::mmap callback Add the perf_evlist_mmap_ops::mmap callback to be called in mmap_per_evsel() to actually mmap the map. Add libperf's perf_evlist__mmap_cb_mmap() function as libperf's mmap callback. New mmaped map gets refcount set to 2 in mmap__mmap(), we follow that in mmap callback. We will move this to common place after we switch to perf_evlist__mmap(). Signed-off-by: Jiri Olsa <jo...@kernel.org> Cc: Alexander Shishkin <alexander.shish...@linux.intel.com> Cc: Michael Petlan <mpet...@redhat.com> Cc: Namhyung Kim <namhy...@kernel.org> Cc: Peter Zijlstra <pet...@infradead.org> Link: http://lore.kernel.org/lkml/20191007125344.14268-18-jo...@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com> --- tools/perf/lib/evlist.c | 29 ++++++++++++++++++++--- tools/perf/lib/include/internal/evlist.h | 3 ++- 2 files changed, 29 insertions(+), 3 deletions(-) diff --git a/tools/perf/lib/evlist.c b/tools/perf/lib/evlist.c index 4f49de5..b697226 100644 --- a/tools/perf/lib/evlist.c +++ b/tools/perf/lib/evlist.c @@ -359,6 +359,28 @@ perf_evlist__mmap_cb_get(struct perf_evlist *evlist, bool overwrite, int idx) #define FD(e, x, y) (*(int *) xyarray__entry(e->fd, x, y)) 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); +} + +static int mmap_per_evsel(struct perf_evlist *evlist, struct perf_evlist_mmap_ops *ops, int idx, struct perf_mmap_param *mp, int cpu_idx, int thread, int *_output, int *_output_overwrite) @@ -396,7 +418,7 @@ mmap_per_evsel(struct perf_evlist *evlist, struct perf_evlist_mmap_ops *ops, if (*output == -1) { *output = fd; - if (perf_mmap__mmap(map, mp, *output, evlist_cpu) < 0) + if (ops->mmap(map, mp, *output, evlist_cpu) < 0) return -1; } else { if (ioctl(fd, PERF_EVENT_IOC_SET_OUTPUT, *output) != 0) @@ -488,7 +510,7 @@ int perf_evlist__mmap_ops(struct perf_evlist *evlist, const struct perf_cpu_map *cpus = evlist->cpus; const struct perf_thread_map *threads = evlist->threads; - if (!ops || !ops->get) + if (!ops || !ops->get || !ops->mmap) return -EINVAL; if (!evlist->mmap) @@ -513,7 +535,8 @@ int perf_evlist__mmap(struct perf_evlist *evlist, int pages) { struct perf_mmap_param mp; struct perf_evlist_mmap_ops ops = { - .get = perf_evlist__mmap_cb_get, + .get = perf_evlist__mmap_cb_get, + .mmap = perf_evlist__mmap_cb_mmap, }; evlist->mmap_len = (pages + 1) * page_size; diff --git a/tools/perf/lib/include/internal/evlist.h b/tools/perf/lib/include/internal/evlist.h index 9bc3a21..b201970 100644 --- a/tools/perf/lib/include/internal/evlist.h +++ b/tools/perf/lib/include/internal/evlist.h @@ -31,10 +31,13 @@ typedef void (*perf_evlist_mmap__cb_idx_t)(struct perf_evlist*, struct perf_mmap_param*, int, bool); typedef struct perf_mmap* (*perf_evlist_mmap__cb_get_t)(struct perf_evlist*, bool, int); +typedef int +(*perf_evlist_mmap__cb_mmap_t)(struct perf_mmap*, struct perf_mmap_param*, int, int); struct perf_evlist_mmap_ops { perf_evlist_mmap__cb_idx_t idx; perf_evlist_mmap__cb_get_t get; + perf_evlist_mmap__cb_mmap_t mmap; }; int perf_evlist__alloc_pollfd(struct perf_evlist *evlist);
