perf test 6: Fix missing kvm module load for s390

Command

   # perf test -Fv 6

fails with error

   running test 100 'kvm-s390:kvm_s390_create_vm' failed to parse
    event 'kvm-s390:kvm_s390_create_vm', err -1, str 'unknown tracepoint'
    event syntax error: 'kvm-s390:kvm_s390_create_vm'
                         \___ unknown tracepoint

when the kvm module is not loaded or not built in.

Fix this by adding a valid function which tests if the module
is loaded. Loaded modules (or builtin KVM support) have a
directory named
  /sys/kernel/debug/tracing/events/kvm-s390
for this tracepoint.

Check for existence of this directory.

Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20190604053504.43073-1-tmricht@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Thomas Richter 2019-06-04 07:35:04 +02:00 committed by Arnaldo Carvalho de Melo
parent a77a05e233
commit 53fe307dfd

View file

@ -18,6 +18,32 @@
#define PERF_TP_SAMPLE_TYPE (PERF_SAMPLE_RAW | PERF_SAMPLE_TIME | \
PERF_SAMPLE_CPU | PERF_SAMPLE_PERIOD)
#if defined(__s390x__)
/* Return true if kvm module is available and loaded. Test this
* and retun success when trace point kvm_s390_create_vm
* exists. Otherwise this test always fails.
*/
static bool kvm_s390_create_vm_valid(void)
{
char *eventfile;
bool rc = false;
eventfile = get_events_file("kvm-s390");
if (eventfile) {
DIR *mydir = opendir(eventfile);
if (mydir) {
rc = true;
closedir(mydir);
}
put_events_file(eventfile);
}
return rc;
}
#endif
static int test__checkevent_tracepoint(struct perf_evlist *evlist)
{
struct perf_evsel *evsel = perf_evlist__first(evlist);
@ -1642,6 +1668,7 @@ static struct evlist_test test__events[] = {
{
.name = "kvm-s390:kvm_s390_create_vm",
.check = test__checkevent_tracepoint,
.valid = kvm_s390_create_vm_valid,
.id = 100,
},
#endif