Using perf_evlist__strerror in kvm/record/top/trace commands
to handle perf_evlist__mmap failures.
Examples with kernel not supporting event ID ioctl:
* record session before:
$ perf.old record -e '{cycles,cache-misses}:S' ls
failed to mmap with 25 (Inappropriate ioctl for device)
ls: Terminated
* record session now:
$ perf record -e '{cycles,cache-misses}:S' ls
Cannot read event group on this kernel.
Please consider kernel update (v3.12+).
ls: Terminated
Examples with session allocating ring buffer with the
size over the allowed threshold.
* record session before:
$ perf record -m 10M ls
rounding mmap pages size to 16777216 bytes (4096 pages)
Permission error mapping pages.
Consider increasing /proc/sys/kernel/perf_event_mlock_kb,
or try again with a smaller value of -m/--mmap_pages.
(current size: 16781312B)
ls: Terminated
* record session now:
$ perf record -m 10M ls
rounding mmap pages size to 16777216 bytes (4096 pages)
Permission error mapping pages.
Consider increasing /proc/sys/kernel/perf_event_mlock_kb,
or try again with a smaller value of -m/--mmap_pages.
(current value: 4096)
ls: Terminated
* top session, before:
$ perf top -m 100M --stdio
rounding mmap pages size to 134217728 bytes (32768 pages)
Error:
Failed to mmap with 1 (Operation not permitted)
* top session, now:
$ perf top -m 100M --stdio
rounding mmap pages size to 134217728 bytes (32768 pages)
Error:
Permission error mapping pages.
Consider increasing /proc/sys/kernel/perf_event_mlock_kb,
or try again with a smaller value of -m/--mmap_pages.
(current size: 134221824B)
* trace session, before:
$ perf trace -m 100M ./ex
rounding mmap pages size to 16777216 bytes (4096 pages)
Permission error mapping pages.
Consider increasing /proc/sys/kernel/perf_event_mlock_kb,
or try again with a smaller value of -m/--mmap_pages.
(current value: 4096)
ls: Terminated
* trace session, now:
$ perf trace -m 100M ./ex
rounding mmap pages size to 134217728 bytes (32768 pages)
Permission error mapping pages.
Consider increasing /proc/sys/kernel/perf_event_mlock_kb,
or try again with a smaller value of -m/--mmap_pages.
(current size: 134221824B)
* kvm stat live session, before:
$ perf kvm stat live -m 10000M
rounding mmap pages size to 17179869184 bytes (4194304 pages)
Error:
Failed to mmap the events: Cannot allocate memory
* kvm stat live session, now:
$ perf kvm stat live -m 10000M
rounding mmap pages size to 17179869184 bytes (4194304 pages)
Error:
Failed to mmap events with error 12 (Cannot allocate memory)
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/builtin-kvm.c | 2 +-
tools/perf/builtin-record.c | 13 ++-----------
tools/perf/builtin-top.c | 3 +--
tools/perf/builtin-trace.c | 2 +-
4 files changed, 5 insertions(+), 15 deletions(-)
diff --git a/tools/perf/builtin-kvm.c b/tools/perf/builtin-kvm.c
index f8bf5f2..131781f 100644
--- a/tools/perf/builtin-kvm.c
+++ b/tools/perf/builtin-kvm.c
@@ -1210,7 +1210,7 @@ static int kvm_live_open_events(struct perf_kvm_stat *kvm)
}
if (perf_evlist__mmap(evlist, kvm->opts.mmap_pages, false) < 0) {
- ui__error("Failed to mmap the events: %s\n", strerror(errno));
+ ui__error("%s", perf_evlist__strerror(evlist));
perf_evlist__close(evlist);
goto out;
}
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index d93e2ee..f697362 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -219,17 +219,8 @@ try_again:
}
if (perf_evlist__mmap(evlist, opts->mmap_pages, false) < 0) {
- if (errno == EPERM) {
- pr_err("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 value: %d)\n", opts->mmap_pages);
- rc = -errno;
- } else {
- pr_err("failed to mmap with %d (%s)\n", errno,
strerror(errno));
- rc = -errno;
- }
+ pr_err("%s", perf_evlist__strerror(evlist));
+ rc = -errno;
goto out;
}
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 03d37a7..3825495 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -879,8 +879,7 @@ try_again:
}
if (perf_evlist__mmap(evlist, opts->mmap_pages, false) < 0) {
- ui__error("Failed to mmap with %d (%s)\n",
- errno, strerror(errno));
+ ui__error("%s", perf_evlist__strerror(evlist));
goto out_err;
}
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index f2886c7..2fed70b 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -1898,7 +1898,7 @@ static int trace__run(struct trace *trace, int argc,
const char **argv)
err = perf_evlist__mmap(evlist, trace->opts.mmap_pages, false);
if (err < 0) {
- fprintf(trace->output, "Couldn't mmap the events: %s\n",
strerror(errno));
+ fprintf(trace->output, "%s", perf_evlist__strerror(evlist));
goto out_close_evlist;
}
--
1.8.3.1
--
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