Re: [PATCH 4.9 033/223] perf test 6: Fix missing kvm module load for s390

Ben Hutchings
2019-08-28T00:12:55Z

[-- Attachment #1: Type: text/plain, Size: 3950 bytes --]

On Fri, 2019-08-02 at 11:34 +0200, Greg Kroah-Hartman wrote:
> [ Upstream commit 53fe307dfd309e425b171f6272d64296a54f4dff ]

This results in numerous compiler errors:

tests/parse-events.c: In function 'kvm_s390_create_vm_valid':
tests/parse-events.c:25:14: error: implicit declaration of function 'get_events_file' [-Werror=implicit-function-declaration]
eventfile = get_events_file("kvm-s390");
^~~~~~~~~~~~~~~
tests/parse-events.c:25:12: error: assignment makes pointer from integer without a cast [-Werror=int-conversion]
eventfile = get_events_file("kvm-s390");
^
tests/parse-events.c:34:3: error: implicit declaration of function 'put_events_file' [-Werror=implicit-function-declaration]
put_events_file(eventfile);
^~~~~~~~~~~~~~~
tests/parse-events.c: At top level:
tests/parse-events.c:1622:3: error: unknown field 'valid' specified in initializer
.valid = kvm_s390_create_vm_valid,
^
tests/parse-events.c:1622:12: error: excess elements in struct initializer [-Werror]
.valid = kvm_s390_create_vm_valid,
^~~~~~~~~~~~~~~~~~~~~~~~
tests/parse-events.c:1622:12: note: (near initialization for 'test__events[45]')

It is using functions that were only added in Linux 4.18 so I think it
should be reverted from the 4.4, 4.9, and 4.14 stable branches.

Ben.

> 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>
> Signed-off-by: Sasha Levin <sashal@kernel.org>
> ---
> tools/perf/tests/parse-events.c | 27 +++++++++++++++++++++++++++
> 1 file changed, 27 insertions(+)
>
> diff --git a/tools/perf/tests/parse-events.c b/tools/perf/tests/parse-events.c
> index aa9276bfe3e9..9134a0c3e99d 100644
> --- a/tools/perf/tests/parse-events.c
> +++ b/tools/perf/tests/parse-events.c
> @@ -12,6 +12,32 @@
> #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);
> @@ -1593,6 +1619,7 @@ 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
--
Ben Hutchings
If the facts do not conform to your theory, they must be disposed of.

[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 833 bytes --]