From c0a54341c0e89333ef201fc3f3001176962f6121 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Thu, 13 Dec 2012 14:16:30 -0300 Subject: perf evsel: Introduce event fallback method The only fallback right now is for HW cpu-cycles -> SW cpu-clock, that was done in the same way in both 'top' and 'record'. Cc: David Ahern Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Mike Galbraith Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/n/tip-58l1mgibh9oa9m0pd3fasxa5@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/evsel.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) (limited to 'tools/perf/util/evsel.c') diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index ee6ee3f45c2a..0c88e5c12dab 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -1378,3 +1378,31 @@ int perf_evsel__fprintf(struct perf_evsel *evsel, fputc('\n', fp); return ++printed; } + +bool perf_evsel__fallback(struct perf_evsel *evsel, int err, + char *msg, size_t msgsize) +{ + if ((err == ENOENT || err == ENXIO) && + evsel->attr.type == PERF_TYPE_HARDWARE && + evsel->attr.config == PERF_COUNT_HW_CPU_CYCLES) { + /* + * If it's cycles then fall back to hrtimer based + * cpu-clock-tick sw counter, which is always available even if + * no PMU support. + * + * PPC returns ENXIO until 2.6.37 (behavior changed with commit + * b0a873e). + */ + scnprintf(msg, msgsize, "%s", +"The cycles event is not supported, trying to fall back to cpu-clock-ticks"); + + evsel->attr.type = PERF_TYPE_SOFTWARE; + evsel->attr.config = PERF_COUNT_SW_CPU_CLOCK; + + free(evsel->name); + evsel->name = NULL; + return true; + } + + return false; +} -- cgit v1.2.3