From 32fdc2ca7e2ae8ae5d0ff660ca7783acd8ee6396 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Mon, 7 Oct 2019 14:53:19 +0200 Subject: libperf: Adopt perf_mmap__read_done() from tools/perf Move perf_mmap__read_init() from tools/perf to libperf and export it in the perf/mmap.h header. Signed-off-by: Jiri Olsa Cc: Alexander Shishkin Cc: Michael Petlan Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lore.kernel.org/lkml/20191007125344.14268-12-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/lib/include/perf/mmap.h | 1 + tools/perf/lib/libperf.map | 1 + tools/perf/lib/mmap.c | 17 +++++++++++++++++ 3 files changed, 19 insertions(+) (limited to 'tools/perf/lib') diff --git a/tools/perf/lib/include/perf/mmap.h b/tools/perf/lib/include/perf/mmap.h index 646e9052b003..4f946e7f724b 100644 --- a/tools/perf/lib/include/perf/mmap.h +++ b/tools/perf/lib/include/perf/mmap.h @@ -8,5 +8,6 @@ struct perf_mmap; LIBPERF_API void perf_mmap__consume(struct perf_mmap *map); LIBPERF_API int perf_mmap__read_init(struct perf_mmap *map); +LIBPERF_API void perf_mmap__read_done(struct perf_mmap *map); #endif /* __LIBPERF_MMAP_H */ diff --git a/tools/perf/lib/libperf.map b/tools/perf/lib/libperf.map index bc3fbb213a3e..7e3ea2e9c917 100644 --- a/tools/perf/lib/libperf.map +++ b/tools/perf/lib/libperf.map @@ -42,6 +42,7 @@ LIBPERF_0.0.1 { perf_evlist__poll; perf_mmap__consume; perf_mmap__read_init; + perf_mmap__read_done; local: *; }; diff --git a/tools/perf/lib/mmap.c b/tools/perf/lib/mmap.c index fdbc6c550dea..97297cba44e3 100644 --- a/tools/perf/lib/mmap.c +++ b/tools/perf/lib/mmap.c @@ -175,3 +175,20 @@ int perf_mmap__read_init(struct perf_mmap *map) return __perf_mmap__read_init(map); } + +/* + * Mandatory for overwrite mode + * The direction of overwrite mode is backward. + * The last perf_mmap__read() will set tail to map->core.prev. + * Need to correct the map->core.prev to head which is the end of next read. + */ +void perf_mmap__read_done(struct perf_mmap *map) +{ + /* + * Check if event was unmapped due to a POLLHUP/POLLERR. + */ + if (!refcount_read(&map->refcnt)) + return; + + map->prev = perf_mmap__read_head(map); +} -- cgit v1.2.3