perf evlist: Use atomic.h for the perf_mmap refcount

Now that we have atomic.h, we should convert all of the existing
refcounts to use it.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-qhpv2etncj3hfofgj1aitkyv@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 7ec1bf93ab28a90d6ae54663947c6e040faaa5a0..dc1dc2c181ef22c2a8f33df66a3b0ed2bcbf9f2d 100644 (file)
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -700,14 +700,14 @@ static bool perf_mmap__empty(struct perf_mmap *md)
 
 static void perf_evlist__mmap_get(struct perf_evlist *evlist, int idx)
 {
-       ++evlist->mmap[idx].refcnt;
+       atomic_inc(&evlist->mmap[idx].refcnt);
 }
 
 static void perf_evlist__mmap_put(struct perf_evlist *evlist, int idx)
 {
-       BUG_ON(evlist->mmap[idx].refcnt == 0);
+       BUG_ON(atomic_read(&evlist->mmap[idx].refcnt) == 0);
 
-       if (--evlist->mmap[idx].refcnt == 0)
+       if (atomic_dec_and_test(&evlist->mmap[idx].refcnt))
                __perf_evlist__munmap(evlist, idx);
 }
 
@@ -721,7 +721,7 @@ void perf_evlist__mmap_consume(struct perf_evlist *evlist, int idx)
                perf_mmap__write_tail(md, old);
        }
 
-       if (md->refcnt == 1 && perf_mmap__empty(md))
+       if (atomic_read(&md->refcnt) == 1 && perf_mmap__empty(md))
                perf_evlist__mmap_put(evlist, idx);
 }
 
@@ -758,7 +758,7 @@ static void __perf_evlist__munmap(struct perf_evlist *evlist, int idx)
        if (evlist->mmap[idx].base != NULL) {
                munmap(evlist->mmap[idx].base, evlist->mmap_len);
                evlist->mmap[idx].base = NULL;
-               evlist->mmap[idx].refcnt = 0;
+               atomic_set(&evlist->mmap[idx].refcnt, 0);
        }
        auxtrace_mmap__munmap(&evlist->mmap[idx].auxtrace_mmap);
 }
@@ -807,7 +807,7 @@ static int __perf_evlist__mmap(struct perf_evlist *evlist, int idx,
         * evlist layer can't just drop it when filtering events in
         * perf_evlist__filter_pollfd().
         */
-       evlist->mmap[idx].refcnt = 2;
+       atomic_set(&evlist->mmap[idx].refcnt, 2);
        evlist->mmap[idx].prev = 0;
        evlist->mmap[idx].mask = mp->mask;
        evlist->mmap[idx].base = mmap(NULL, evlist->mmap_len, mp->prot,

diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index c07b1a94a7249169440bc81401e58fdd6ba5e98f..670e7f2114b1d0ecc47572829901d31dc784ba5b 100644 (file)
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -1,6 +1,7 @@
 #ifndef __PERF_EVLIST_H
 #define __PERF_EVLIST_H 1
 
+#include <linux/atomic.h>
 #include <linux/list.h>
 #include <api/fd/array.h>
 #include <stdio.h>
@@ -27,7 +28,7 @@ struct record_opts;
 struct perf_mmap {
        void             *base;
        int              mask;
-       int              refcnt;
+       atomic_t         refcnt;
        u64              prev;
        struct auxtrace_mmap auxtrace_mmap;
        char             event_copy[PERF_SAMPLE_MAX_SIZE] __attribute__((aligned(8)));