Adding internal error (PERF_EVLIST__ERRNO_MMAP) for case
when 'mmap' syscall fails.
Signed-off-by: Jiri Olsa <jo...@redhat.com>
Cc: Corey Ashford <cjash...@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweis...@gmail.com>
Cc: Ingo Molnar <mi...@elte.hu>
Cc: Namhyung Kim <namhy...@kernel.org>
Cc: Paul Mackerras <pau...@samba.org>
Cc: Peter Zijlstra <a.p.zijls...@chello.nl>
Cc: Arnaldo Carvalho de Melo <a...@redhat.com>
Cc: David Ahern <dsah...@gmail.com>
Cc: Andi Kleen <a...@firstfloor.org>
---
tools/perf/util/evlist.c | 28 ++++++++++++++++++++++++++++
tools/perf/util/evlist.h | 1 +
2 files changed, 29 insertions(+)
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index dfb72d4..d156f0a 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -605,6 +605,28 @@ static int perf_evlist__alloc_mmap(struct perf_evlist
*evlist)
return evlist->mmap != NULL ? 0 : -ENOMEM;
}
+static void strerror_mmap(struct perf_evlist *evlist,
+ char *buf, size_t size)
+{
+ int err_libc = evlist->err_libc;
+
+ switch (evlist->err_libc) {
+ case EPERM:
+ scnprintf(buf, size,
+ "Permission error mapping pages.\n"
+ "Consider increasing "
+ "/proc/sys/kernel/perf_event_mlock_kb,\n"
+ "or try again with a smaller value of
-m/--mmap_pages.\n"
+ "(current size: %dB)\n", evlist->mmap_len);
+ break;
+ default:
+ scnprintf(buf, size,
+ "Failed to mmap events with error %d (%s)\n",
+ err_libc, strerror(err_libc));
+ break;
+ }
+}
+
static void __perf_evlist__strerror(struct perf_evlist *evlist,
char *buf, size_t size)
{
@@ -614,6 +636,9 @@ static void __perf_evlist__strerror(struct perf_evlist
*evlist,
switch (err) {
case PERF_EVLIST__ERRNO_SUCCESS:
break;
+ case PERF_EVLIST__ERRNO_MMAP:
+ strerror_mmap(evlist, buf, size);
+ return;
default:
scnprintf(buf, size, "Unknown error\n");
return;
@@ -642,6 +667,7 @@ static int __perf_evlist__mmap(struct perf_evlist *evlist,
MAP_SHARED, fd, 0);
if (evlist->mmap[idx].base == MAP_FAILED) {
+ SET_ERR(MMAP);
pr_debug2("failed to mmap perf event ring buffer, error %d\n",
errno);
evlist->mmap[idx].base = NULL;
@@ -821,6 +847,8 @@ int perf_evlist__mmap(struct perf_evlist *evlist, unsigned
int pages,
const struct thread_map *threads = evlist->threads;
int prot = PROT_READ | (overwrite ? 0 : PROT_WRITE), mask;
+ SET_ERR(SUCCESS);
+
if (evlist->mmap == NULL && perf_evlist__alloc_mmap(evlist) < 0)
return -ENOMEM;
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index 9832fbd..02df99a 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -19,6 +19,7 @@ struct perf_record_opts;
enum {
PERF_EVLIST__ERRNO_SUCCESS = 0,
+ PERF_EVLIST__ERRNO_MMAP = 1,
};
struct perf_mmap {
--
1.8.3.1
--
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