linux/tools/perf/lib/mmap.c
Jiri Olsa 80e53d1148 libperf: Adopt perf_mmap__put() function from tools/perf
Move perf_mmap__put() from tools/perf to libperf.

Once perf_mmap__put() is moved, we need a way to call application
related unmap code (AIO and aux related code for eprf), when the map
goes away.

Add the perf_mmap::unmap callback to do that.

The unmap path from perf is:

  perf_mmap__put                           (libperf)
    perf_mmap__munmap                      (libperf)
      map->unmap_cb -> perf_mmap__unmap_cb (perf)
        mmap__munmap                       (perf)

Committer notes:

Add missing linux/kernel.h to tools/perf/lib/mmap.c to get the BUG_ON
definition.

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/20191007125344.14268-8-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-10-10 10:09:25 -03:00

61 lines
1.2 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <sys/mman.h>
#include <internal/mmap.h>
#include <internal/lib.h>
#include <linux/kernel.h>
void perf_mmap__init(struct perf_mmap *map, bool overwrite,
libperf_unmap_cb_t unmap_cb)
{
map->fd = -1;
map->overwrite = overwrite;
map->unmap_cb = unmap_cb;
refcount_set(&map->refcnt, 0);
}
size_t perf_mmap__mmap_len(struct perf_mmap *map)
{
return map->mask + 1 + page_size;
}
int perf_mmap__mmap(struct perf_mmap *map, struct perf_mmap_param *mp,
int fd, int cpu)
{
map->prev = 0;
map->mask = mp->mask;
map->base = mmap(NULL, perf_mmap__mmap_len(map), mp->prot,
MAP_SHARED, fd, 0);
if (map->base == MAP_FAILED) {
map->base = NULL;
return -1;
}
map->fd = fd;
map->cpu = cpu;
return 0;
}
void perf_mmap__munmap(struct perf_mmap *map)
{
if (map && map->base != NULL) {
munmap(map->base, perf_mmap__mmap_len(map));
map->base = NULL;
map->fd = -1;
refcount_set(&map->refcnt, 0);
}
if (map && map->unmap_cb)
map->unmap_cb(map);
}
void perf_mmap__get(struct perf_mmap *map)
{
refcount_inc(&map->refcnt);
}
void perf_mmap__put(struct perf_mmap *map)
{
BUG_ON(map->base && refcount_read(&map->refcnt) == 0);
if (refcount_dec_and_test(&map->refcnt))
perf_mmap__munmap(map);
}