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authorSong Liu <songliubraving@fb.com>2021-10-06 22:02:31 -0700
committerAndrii Nakryiko <andrii@kernel.org>2021-10-07 21:51:04 -0700
commitaa67fdb4643616f04cb59b6d090010c371ab1a80 (patch)
tree17f11d2fb60a7921036df220f5b70ae12acd08ae /tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c
parent0eb4ef88c53f7169c44b1bd2ace5389981409a60 (diff)
downloadlinux-aa67fdb4643616f04cb59b6d090010c371ab1a80.tar.bz2
selftests/bpf: Skip the second half of get_branch_snapshot in vm
VMs running on upstream 5.12+ kernel support LBR. However, bpf_get_branch_snapshot couldn't stop the LBR before too many entries are flushed. Skip the hit/waste test for VMs before we find a proper fix for LBR in VM. Fixes: 025bd7c753aa ("selftests/bpf: Add test for bpf_get_branch_snapshot") Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211007050231.728496-1-songliubraving@fb.com
Diffstat (limited to 'tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c')
-rw-r--r--tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c34
1 files changed, 34 insertions, 0 deletions
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 67e86f8d8677..e4f92feb7b32 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 (!strncmp(line, "flags", 5)) {
+ 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};
@@ -83,6 +107,16 @@ void test_get_branch_snapshot(void)
goto cleanup;
}
+ if (is_hypervisor()) {
+ /* As of today, LBR in hypervisor cannot be stopped before
+ * too many entries are flushed. Skip the hit/waste test
+ * for now in hypervisor until we optimize the LBR in
+ * hypervisor.
+ */
+ test__skip();
+ goto cleanup;
+ }
+
ASSERT_GT(skel->bss->test1_hits, 6, "find_looptest_in_lbr");
/* Given we stop LBR in software, we will waste a few entries.