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| author | Kan Liang <kan.liang@intel.com> | 2018-01-18 13:26:28 -0800 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2018-02-15 09:56:14 -0300 |
| commit | 204721d7eabe6ee98aafce791ce3efdbc4715834 (patch) | |
| tree | 3ccd81207b51196891ee646a3fcd6186ada2a6a7 | |
| parent | 9a831b3a32c5daf5d7cc672334d51930f78e4ea3 (diff) | |
| download | linux-stable-204721d7eabe6ee98aafce791ce3efdbc4715834.tar.gz linux-stable-204721d7eabe6ee98aafce791ce3efdbc4715834.tar.bz2 linux-stable-204721d7eabe6ee98aafce791ce3efdbc4715834.zip | |
perf top: Add overwrite fall back
Switch to non-overwrite mode if kernel doesnot support overwrite
ringbuffer.
It's only effect when overwrite mode is supported. No change to current
behavior.
Signed-off-by: Kan Liang <kan.liang@intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1516310792-208685-14-git-send-email-kan.liang@intel.com
[ Use perf_missing_features.write_backward instead of the non merged is_write_backward_fail() ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| -rw-r--r-- | tools/perf/builtin-top.c | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c index 17783798924a..ee4bba1e282c 100644 --- a/tools/perf/builtin-top.c +++ b/tools/perf/builtin-top.c @@ -943,6 +943,27 @@ static int perf_top__overwrite_check(struct perf_top *top) return 0; } +static int perf_top_overwrite_fallback(struct perf_top *top, + struct perf_evsel *evsel) +{ + struct record_opts *opts = &top->record_opts; + struct perf_evlist *evlist = top->evlist; + struct perf_evsel *counter; + + if (!opts->overwrite) + return 0; + + /* only fall back when first event fails */ + if (evsel != perf_evlist__first(evlist)) + return 0; + + evlist__for_each_entry(evlist, counter) + counter->attr.write_backward = false; + opts->overwrite = false; + ui__warning("fall back to non-overwrite mode\n"); + return 1; +} + static int perf_top__start_counters(struct perf_top *top) { char msg[BUFSIZ]; @@ -967,6 +988,21 @@ static int perf_top__start_counters(struct perf_top *top) try_again: if (perf_evsel__open(counter, top->evlist->cpus, top->evlist->threads) < 0) { + + /* + * Specially handle overwrite fall back. + * Because perf top is the only tool which has + * overwrite mode by default, support + * both overwrite and non-overwrite mode, and + * require consistent mode for all events. + * + * May move it to generic code with more tools + * have similar attribute. + */ + if (perf_missing_features.write_backward && + perf_top_overwrite_fallback(top, counter)) + goto try_again; + if (perf_evsel__fallback(counter, errno, msg, sizeof(msg))) { if (verbose > 0) ui__warning("%s\n", msg); |