perf test: Fix libpfm4 support (63) test error for nested event groups

Compiling perf with make LIBPFM4=1 includes libpfm support and
enables test case 63 'Test libpfm4 support'. This test reports an error
on all platforms for subtest 63.2 'test groups of --pfm-events'.
The reported error message is 'nested event groups not supported'

 # ./perf test -F 63
 63: Test libpfm4 support                                            :
 63.1: test of individual --pfm-events                               :
 Error:
 failed to parse event stereolab : event not found
 Error:
 failed to parse event stereolab,instructions : event not found
 Error:
 failed to parse event instructions,stereolab : event not found
  Ok
 63.2: test groups of --pfm-events                                   :
 Error:
 nested event groups not supported    <------ Error message here
 Error:
 failed to parse event {stereolab} : event not found
 Error:
 failed to parse event {instructions,cycles},{instructions,stereolab} :\
	 event not found
 Ok
 #

This patch addresses the error message 'nested event groups not supported'.
The root cause is function parse_libpfm_events_option() which parses the
event string '{},{instructions}' and can not handle a leading empty
group notation '{},...'.

The code detects the first (empty) group indicator '{' but does not
terminate group processing on the following group closing character '}'.
So when the second group indicator '{' is detected, the code assumes
a nested group and returns an error.

With the error message fixed, also change the expected event number to
one for the test case to succeed.

While at it also fix a memory leak. In good case the function does not
free the duplicated string given as first parameter.

Output after:
 # ./perf test -F 63
 63: Test libpfm4 support                                            :
 63.1: test of individual --pfm-events                               :
 Error:
 failed to parse event stereolab : event not found
 Error:
 failed to parse event stereolab,instructions : event not found
 Error:
 failed to parse event instructions,stereolab : event not found
  Ok
 63.2: test groups of --pfm-events                                   :
 Error:
 failed to parse event {stereolab} : event not found
 Error:
 failed to parse event {instructions,cycles},{instructions,stereolab} : \
	 event not found
  Ok
 #
Error message 'nested event groups not supported' is gone.

Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-By: Ian Rogers <irogers@google.com>
Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Link: http://lore.kernel.org/lkml/20210517140931.2559364-1-tmricht@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Thomas Richter 2021-05-17 16:09:31 +02:00 committed by Arnaldo Carvalho de Melo
parent 3c91e8efaf
commit 316a76a58c
2 changed files with 12 additions and 3 deletions

View File

@ -131,8 +131,8 @@ static int test__pfm_group(void)
},
{
.events = "{},{instructions}",
.nr_events = 0,
.nr_groups = 0,
.nr_events = 1,
.nr_groups = 1,
},
{
.events = "{instructions},{instructions}",

View File

@ -62,8 +62,16 @@ int parse_libpfm_events_option(const struct option *opt, const char *str,
}
/* no event */
if (*q == '\0')
if (*q == '\0') {
if (*sep == '}') {
if (grp_evt < 0) {
ui__error("cannot close a non-existing event group\n");
goto error;
}
grp_evt--;
}
continue;
}
memset(&attr, 0, sizeof(attr));
event_attr_init(&attr);
@ -107,6 +115,7 @@ int parse_libpfm_events_option(const struct option *opt, const char *str,
grp_evt = -1;
}
}
free(p_orig);
return 0;
error:
free(p_orig);