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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 <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-58l1mgibh9oa9m0pd3fasxa5@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
hifive-unleashed-5.1
Arnaldo Carvalho de Melo 2012-12-13 14:16:30 -03:00
parent 594ac61ad3
commit c0a54341c0
4 changed files with 37 additions and 37 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
tools/perf/builtin-record.c
View File

@ -224,6 +224,7 @@ static bool perf_evlist__equal(struct perf_evlist *evlist,
static int perf_record__open(struct perf_record *rec)
{
char msg[128];
struct perf_evsel *pos;
struct perf_evlist *evlist = rec->evlist;
struct perf_session *session = rec->session;
@ -249,27 +250,9 @@ try_again:
goto out;
}
/*
* 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).
*/
if ((err == ENOENT || err == ENXIO)
&& attr->type == PERF_TYPE_HARDWARE
&& attr->config == PERF_COUNT_HW_CPU_CYCLES) {
if (perf_evsel__fallback(pos, err, msg, sizeof(msg))) {
if (verbose)
ui__warning("The cycles event is not supported, "
"trying to fall back to cpu-clock-ticks\n");
attr->type = PERF_TYPE_SOFTWARE;
attr->config = PERF_COUNT_SW_CPU_CLOCK;
if (pos->name) {
free(pos->name);
pos->name = NULL;
}
ui__warning("%s\n", msg);
goto try_again;
}

20
tools/perf/builtin-top.c
View File

@ -892,6 +892,7 @@ static void perf_top__mmap_read(struct perf_top *top)
static void perf_top__start_counters(struct perf_top *top)
{
char msg[128];
struct perf_evsel *counter;
struct perf_evlist *evlist = top->evlist;
struct perf_record_opts *opts = &top->record_opts;
@ -909,25 +910,10 @@ try_again:
ui__error_paranoid();
goto out_err;
}
/*
* If it's cycles then fall back to hrtimer
* based cpu-clock-tick sw counter, which
* is always available even if no PMU support:
*/
if ((err == ENOENT || err == ENXIO) &&
(attr->type == PERF_TYPE_HARDWARE) &&
(attr->config == PERF_COUNT_HW_CPU_CYCLES)) {
if (perf_evsel__fallback(counter, err, msg, sizeof(msg))) {
if (verbose)
ui__warning("Cycles event not supported,\n"
"trying to fall back to cpu-clock-ticks\n");
attr->type = PERF_TYPE_SOFTWARE;
attr->config = PERF_COUNT_SW_CPU_CLOCK;
if (counter->name) {
free(counter->name);
counter->name = NULL;
}
ui__warning("%s\n", msg);
goto try_again;
}

28
tools/perf/util/evsel.c
View File

@ -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;
}

3
tools/perf/util/evsel.h
View File

@ -251,4 +251,7 @@ struct perf_attr_details {
int perf_evsel__fprintf(struct perf_evsel *evsel,
struct perf_attr_details *details, FILE *fp);
bool perf_evsel__fallback(struct perf_evsel *evsel, int err,
char *msg, size_t msgsize);
#endif /* __PERF_EVSEL_H */