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authorAnju T Sudhakar <anju@linux.vnet.ibm.com>2019-07-18 23:47:48 +0530
committerArnaldo Carvalho de Melo <acme@redhat.com>2019-09-20 10:28:26 -0300
commit124eb5f82bf9395419b20205c4dcc1b8fcda7f29 (patch)
treebf33b527d49e039fc1b851ce561ad9150b54ef49 /tools/perf/arch
parent8067b3da970baa12e6045400fdf009673b8dd3c2 (diff)
perf kvm: Add arch neutral function to choose event for perf kvm record
'perf kvm record' uses 'cycles'(if the user did not specify any event) as the default event to profile the guest. This will not provide any proper samples from the guest incase of powerpc architecture, since in powerpc the PMUs are controlled by the guest rather than the host. Patch adds a function to pick an arch specific event for 'perf kvm record', instead of selecting 'cycles' as a default event for all architectures. For powerpc this function checks for any user specified event, and if there isn't any it returns invalid instead of proceeding with 'cycles' event. Signed-off-by: Anju T Sudhakar <anju@linux.vnet.ibm.com> Reviewed-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: linuxppc-dev@lists.ozlabs.org Link: http://lore.kernel.org/lkml/20190718181749.30612-2-anju@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/arch')
-rw-r--r--tools/perf/arch/powerpc/util/kvm-stat.c37
1 files changed, 37 insertions, 0 deletions
diff --git a/tools/perf/arch/powerpc/util/kvm-stat.c b/tools/perf/arch/powerpc/util/kvm-stat.c
index f0dbf7b075c8..ec5b771029e4 100644
--- a/tools/perf/arch/powerpc/util/kvm-stat.c
+++ b/tools/perf/arch/powerpc/util/kvm-stat.c
@@ -8,6 +8,7 @@
#include "book3s_hv_exits.h"
#include "book3s_hcalls.h"
+#include <subcmd/parse-options.h>
#define NR_TPS 4
@@ -172,3 +173,39 @@ int cpu_isa_init(struct perf_kvm_stat *kvm, const char *cpuid __maybe_unused)
return ret;
}
+
+/*
+ * Incase of powerpc architecture, pmu registers are programmable
+ * by guest kernel. So monitoring guest via host may not provide
+ * valid samples. It is better to fail the "perf kvm record"
+ * with default "cycles" event to monitor guest in powerpc.
+ *
+ * Function to parse the arguments and return appropriate values.
+ */
+int kvm_add_default_arch_event(int *argc, const char **argv)
+{
+ const char **tmp;
+ bool event = false;
+ int i, j = *argc;
+
+ const struct option event_options[] = {
+ OPT_BOOLEAN('e', "event", &event, NULL),
+ OPT_END()
+ };
+
+ tmp = calloc(j + 1, sizeof(char *));
+ if (!tmp)
+ return -EINVAL;
+
+ for (i = 0; i < j; i++)
+ tmp[i] = argv[i];
+
+ parse_options(j, tmp, event_options, NULL, PARSE_OPT_KEEP_UNKNOWN);
+ if (!event) {
+ free(tmp);
+ return -EINVAL;
+ }
+
+ free(tmp);
+ return 0;
+}