diff options
| author | Jiri Olsa | 2019-10-07 14:53:19 +0200 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo | 2019-10-10 11:45:32 -0300 |
| commit | 32fdc2ca7e2ae8ae5d0ff660ca7783acd8ee6396 (patch) | |
| tree | 9924e96fd7075e5697de48eb3a9984b173389e3a /tools/perf/lib/mmap.c | |
| parent | 7c4d41824f9afc659ba425a41018546531cffd72 (diff) | |
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 <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20191007125344.14268-12-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/lib/mmap.c')
| -rw-r--r-- | tools/perf/lib/mmap.c | 17 |
1 files changed, 17 insertions, 0 deletions
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); +} |