* [PATCH] selftests/bpf: skip get_branch_snapshot in vm
@ 2021-10-06 20:31 Song Liu
2021-10-06 20:38 ` Song Liu
2021-10-06 21:35 ` Andrii Nakryiko
0 siblings, 2 replies; 4+ messages in thread
From: Song Liu @ 2021-10-06 20:31 UTC (permalink / raw)
To: bpf, netdev; +Cc: ast, daniel, andrii, kernel-team, Song Liu
VMs running on latest kernel support LBR. However, bpf_get_branch_snapshot
couldn't stop the LBR before too many entries are flushed. Skip the test
for VMs before we find a proper fix for VMs.
Read the "flags" line from /proc/cpuinfo, if it contains "hypervisor",
skip test get_branch_snapshot.
Fixes: 025bd7c753aa (selftests/bpf: Add test for bpf_get_branch_snapshot)
Signed-off-by: Song Liu <songliubraving@fb.com>
---
.../bpf/prog_tests/get_branch_snapshot.c | 32 +++++++++++++++++++
1 file changed, 32 insertions(+)
diff --git a/tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c b/tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c
index 67e86f8d86775..bf9d47a859449 100644
--- a/tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c
+++ b/tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c
@@ -6,6 +6,30 @@
static int *pfd_array;
static int cpu_cnt;
+static bool is_hypervisor(void)
+{
+ char *line = NULL;
+ bool ret = false;
+ size_t len;
+ FILE *fp;
+
+ fp = fopen("/proc/cpuinfo", "r");
+ if (!fp)
+ return false;
+
+ while (getline(&line, &len, fp) != -1) {
+ if (strstr(line, "flags") == line) {
+ if (strstr(line, "hypervisor") != NULL)
+ ret = true;
+ break;
+ }
+ }
+
+ free(line);
+ fclose(fp);
+ return ret;
+}
+
static int create_perf_events(void)
{
struct perf_event_attr attr = {0};
@@ -54,6 +78,14 @@ void test_get_branch_snapshot(void)
struct get_branch_snapshot *skel = NULL;
int err;
+ if (is_hypervisor()) {
+ /* As of today, LBR in hypervisor cannot be stopped before
+ * too many entries are flushed. Skip the test for now in
+ * hypervisor until we optimize the LBR in hypervisor.
+ */
+ test__skip();
+ return;
+ }
if (create_perf_events()) {
test__skip(); /* system doesn't support LBR */
goto cleanup;
--
2.30.2
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] selftests/bpf: skip get_branch_snapshot in vm
2021-10-06 20:31 [PATCH] selftests/bpf: skip get_branch_snapshot in vm Song Liu
@ 2021-10-06 20:38 ` Song Liu
2021-10-06 21:35 ` Andrii Nakryiko
1 sibling, 0 replies; 4+ messages in thread
From: Song Liu @ 2021-10-06 20:38 UTC (permalink / raw)
To: Song Liu
Cc: bpf, Networking, Alexei Starovoitov, Daniel Borkmann,
Andrii Nakryiko, Kernel Team
On Wed, Oct 6, 2021 at 1:32 PM Song Liu <songliubraving@fb.com> wrote:
>
> VMs running on latest kernel support LBR. However, bpf_get_branch_snapshot
> couldn't stop the LBR before too many entries are flushed. Skip the test
> for VMs before we find a proper fix for VMs.
>
> Read the "flags" line from /proc/cpuinfo, if it contains "hypervisor",
> skip test get_branch_snapshot.
Forgot to use --subject-prefix. This applies to bpf-next.
Thanks,
Song
>
> Fixes: 025bd7c753aa (selftests/bpf: Add test for bpf_get_branch_snapshot)
> Signed-off-by: Song Liu <songliubraving@fb.com>
> ---
> .../bpf/prog_tests/get_branch_snapshot.c | 32 +++++++++++++++++++
> 1 file changed, 32 insertions(+)
>
> diff --git a/tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c b/tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c
> index 67e86f8d86775..bf9d47a859449 100644
> --- a/tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c
> +++ b/tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c
> @@ -6,6 +6,30 @@
> static int *pfd_array;
> static int cpu_cnt;
>
> +static bool is_hypervisor(void)
> +{
> + char *line = NULL;
> + bool ret = false;
> + size_t len;
> + FILE *fp;
> +
> + fp = fopen("/proc/cpuinfo", "r");
> + if (!fp)
> + return false;
> +
> + while (getline(&line, &len, fp) != -1) {
> + if (strstr(line, "flags") == line) {
> + if (strstr(line, "hypervisor") != NULL)
> + ret = true;
> + break;
> + }
> + }
> +
> + free(line);
> + fclose(fp);
> + return ret;
> +}
> +
> static int create_perf_events(void)
> {
> struct perf_event_attr attr = {0};
> @@ -54,6 +78,14 @@ void test_get_branch_snapshot(void)
> struct get_branch_snapshot *skel = NULL;
> int err;
>
> + if (is_hypervisor()) {
> + /* As of today, LBR in hypervisor cannot be stopped before
> + * too many entries are flushed. Skip the test for now in
> + * hypervisor until we optimize the LBR in hypervisor.
> + */
> + test__skip();
> + return;
> + }
> if (create_perf_events()) {
> test__skip(); /* system doesn't support LBR */
> goto cleanup;
> --
> 2.30.2
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] selftests/bpf: skip get_branch_snapshot in vm
2021-10-06 20:31 [PATCH] selftests/bpf: skip get_branch_snapshot in vm Song Liu
2021-10-06 20:38 ` Song Liu
@ 2021-10-06 21:35 ` Andrii Nakryiko
2021-10-07 0:35 ` Song Liu
1 sibling, 1 reply; 4+ messages in thread
From: Andrii Nakryiko @ 2021-10-06 21:35 UTC (permalink / raw)
To: Song Liu
Cc: bpf, Networking, Alexei Starovoitov, Daniel Borkmann,
Andrii Nakryiko, Kernel Team
On Wed, Oct 6, 2021 at 1:31 PM Song Liu <songliubraving@fb.com> wrote:
>
> VMs running on latest kernel support LBR. However, bpf_get_branch_snapshot
> couldn't stop the LBR before too many entries are flushed. Skip the test
> for VMs before we find a proper fix for VMs.
>
> Read the "flags" line from /proc/cpuinfo, if it contains "hypervisor",
> skip test get_branch_snapshot.
>
> Fixes: 025bd7c753aa (selftests/bpf: Add test for bpf_get_branch_snapshot)
missing quotes?
> Signed-off-by: Song Liu <songliubraving@fb.com>
> ---
> .../bpf/prog_tests/get_branch_snapshot.c | 32 +++++++++++++++++++
> 1 file changed, 32 insertions(+)
>
> diff --git a/tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c b/tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c
> index 67e86f8d86775..bf9d47a859449 100644
> --- a/tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c
> +++ b/tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c
> @@ -6,6 +6,30 @@
> static int *pfd_array;
> static int cpu_cnt;
>
> +static bool is_hypervisor(void)
> +{
> + char *line = NULL;
> + bool ret = false;
> + size_t len;
> + FILE *fp;
> +
> + fp = fopen("/proc/cpuinfo", "r");
> + if (!fp)
> + return false;
> +
> + while (getline(&line, &len, fp) != -1) {
> + if (strstr(line, "flags") == line) {
strncmp() would be more explicit. That's what you are trying to do
(prefix match), right?
> + if (strstr(line, "hypervisor") != NULL)
> + ret = true;
> + break;
> + }
> + }
> +
> + free(line);
> + fclose(fp);
> + return ret;
> +}
> +
> static int create_perf_events(void)
> {
> struct perf_event_attr attr = {0};
> @@ -54,6 +78,14 @@ void test_get_branch_snapshot(void)
> struct get_branch_snapshot *skel = NULL;
> int err;
>
> + if (is_hypervisor()) {
> + /* As of today, LBR in hypervisor cannot be stopped before
> + * too many entries are flushed. Skip the test for now in
> + * hypervisor until we optimize the LBR in hypervisor.
> + */
> + test__skip();
> + return;
> + }
> if (create_perf_events()) {
> test__skip(); /* system doesn't support LBR */
> goto cleanup;
> --
> 2.30.2
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] selftests/bpf: skip get_branch_snapshot in vm
2021-10-06 21:35 ` Andrii Nakryiko
@ 2021-10-07 0:35 ` Song Liu
0 siblings, 0 replies; 4+ messages in thread
From: Song Liu @ 2021-10-07 0:35 UTC (permalink / raw)
To: Andrii Nakryiko
Cc: Song Liu, bpf, Networking, Alexei Starovoitov, Daniel Borkmann,
Andrii Nakryiko, Kernel Team
On Wed, Oct 6, 2021 at 2:36 PM Andrii Nakryiko
<andrii.nakryiko@gmail.com> wrote:
>
> On Wed, Oct 6, 2021 at 1:31 PM Song Liu <songliubraving@fb.com> wrote:
> >
> > VMs running on latest kernel support LBR. However, bpf_get_branch_snapshot
> > couldn't stop the LBR before too many entries are flushed. Skip the test
> > for VMs before we find a proper fix for VMs.
> >
> > Read the "flags" line from /proc/cpuinfo, if it contains "hypervisor",
> > skip test get_branch_snapshot.
> >
> > Fixes: 025bd7c753aa (selftests/bpf: Add test for bpf_get_branch_snapshot)
>
> missing quotes?
Aha, I copied this line from e31eec77e4ab90dcec7d2da93415f839098dc287. Will fix.
>
> > Signed-off-by: Song Liu <songliubraving@fb.com>
> > ---
> > .../bpf/prog_tests/get_branch_snapshot.c | 32 +++++++++++++++++++
> > 1 file changed, 32 insertions(+)
> >
> > diff --git a/tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c b/tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c
> > index 67e86f8d86775..bf9d47a859449 100644
> > --- a/tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c
> > +++ b/tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c
> > @@ -6,6 +6,30 @@
> > static int *pfd_array;
> > static int cpu_cnt;
> >
> > +static bool is_hypervisor(void)
> > +{
> > + char *line = NULL;
> > + bool ret = false;
> > + size_t len;
> > + FILE *fp;
> > +
> > + fp = fopen("/proc/cpuinfo", "r");
> > + if (!fp)
> > + return false;
> > +
> > + while (getline(&line, &len, fp) != -1) {
> > + if (strstr(line, "flags") == line) {
>
> strncmp() would be more explicit. That's what you are trying to do
> (prefix match), right?
right... let me fix it in v2.
>
> > + if (strstr(line, "hypervisor") != NULL)
> > + ret = true;
> > + break;
> > + }
> > + }
> > +
> > + free(line);
> > + fclose(fp);
> > + return ret;
> > +}
> > +
> > static int create_perf_events(void)
> > {
> > struct perf_event_attr attr = {0};
> > @@ -54,6 +78,14 @@ void test_get_branch_snapshot(void)
> > struct get_branch_snapshot *skel = NULL;
> > int err;
> >
> > + if (is_hypervisor()) {
> > + /* As of today, LBR in hypervisor cannot be stopped before
> > + * too many entries are flushed. Skip the test for now in
> > + * hypervisor until we optimize the LBR in hypervisor.
> > + */
> > + test__skip();
> > + return;
> > + }
> > if (create_perf_events()) {
> > test__skip(); /* system doesn't support LBR */
> > goto cleanup;
> > --
> > 2.30.2
> >
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2021-10-07 0:35 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-10-06 20:31 [PATCH] selftests/bpf: skip get_branch_snapshot in vm Song Liu
2021-10-06 20:38 ` Song Liu
2021-10-06 21:35 ` Andrii Nakryiko
2021-10-07 0:35 ` Song Liu
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.