Add a fd field into perf_mmap so perf can track fd from mmap.
This feature will be used for toggling overwrite ring buffers.
Signed-off-by: Wang Nan <wangn...@huawei.com>
Signed-off-by: He Kuang <heku...@huawei.com>
Cc: Arnaldo Carvalho de Melo <a...@redhat.com>
Cc: Jiri Olsa <jo...@kernel.org>
Cc: Masami Hiramatsu <masami.hiramatsu...@hitachi.com>
Cc: Namhyung Kim <namhy...@kernel.org>
Cc: Zefan Li <lize...@huawei.com>
Cc: pi3or...@163.com
---
tools/perf/util/evlist.c | 15 +++++++++++++--
tools/perf/util/evlist.h | 1 +
2 files changed, 14 insertions(+), 2 deletions(-)
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index dc2e509..4295d7e 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -943,6 +943,7 @@ 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].fd = -1;
atomic_set(&evlist->mmap[idx].refcnt, 0);
}
auxtrace_mmap__munmap(&evlist->mmap[idx].auxtrace_mmap);
@@ -973,7 +974,7 @@ void perf_evlist__munmap(struct perf_evlist *evlist)
static int perf_evlist__alloc_mmap(struct perf_evlist *evlist)
{
- int total_mmaps;
+ int total_mmaps, i;
evlist->nr_mmaps = cpu_map__nr(evlist->cpus);
if (cpu_map__empty(evlist->cpus))
@@ -984,7 +985,12 @@ static int perf_evlist__alloc_mmap(struct perf_evlist
*evlist)
return -EINVAL;
evlist->mmap = zalloc(total_mmaps * sizeof(struct perf_mmap));
- return evlist->mmap != NULL ? 0 : -ENOMEM;
+ if (!evlist->mmap)
+ return -ENOMEM;
+
+ for (i = 0; i < total_mmaps; i++)
+ evlist->mmap[i].fd = -1;
+ return 0;
}
struct mmap_params {
@@ -1004,6 +1010,10 @@ static int __perf_evlist__mmap(struct perf_evlist
*evlist, int idx,
if (!perf_evlist__channel_check(evlist, channel, RDONLY))
prot |= PROT_WRITE;
+ if (evlist->mmap[idx].fd >= 0) {
+ pr_err("idx %d already mapped\n", idx);
+ return -1;
+ }
/*
* The last one will be done at perf_evlist__mmap_consume(), so that we
* make sure we don't prevent tools from consuming every last event in
@@ -1028,6 +1038,7 @@ static int __perf_evlist__mmap(struct perf_evlist
*evlist, int idx,
evlist->mmap[idx].base = NULL;
return -1;
}
+ evlist->mmap[idx].fd = fd;
if (auxtrace_mmap__mmap(&evlist->mmap[idx].auxtrace_mmap,
&mp->auxtrace_mp, evlist->mmap[idx].base, fd))
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index bdd8e98..ee17449 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -35,6 +35,7 @@ enum perf_evlist_mmap_flag {
struct perf_mmap {
void *base;
int mask;
+ int fd;
atomic_t refcnt;
u64 prev;
struct auxtrace_mmap auxtrace_mmap;
--
1.8.3.4
