[PATCH 2/2] perf kvm: Disable live command if timerfd is not supported

From: David Ahern
Date: Tue Oct 29 2013 - 12:43:33 EST


If the OS does not have timerfd support (e.g., older OS'es like RHEL5)
disable perf kvm stat live.

Signed-off-by: David Ahern <dsahern@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
---
tools/perf/builtin-kvm.c | 12 ++++++++++++
tools/perf/config/Makefile | 7 +++++++
tools/perf/config/feature-checks/Makefile | 6 +++++-
tools/perf/config/feature-checks/test-all.c | 5 +++++
tools/perf/config/feature-checks/test-timerfd.c | 18 ++++++++++++++++++
5 files changed, 47 insertions(+), 1 deletion(-)
create mode 100644 tools/perf/config/feature-checks/test-timerfd.c

diff --git a/tools/perf/builtin-kvm.c b/tools/perf/builtin-kvm.c
index cb05f39d8a77..cd9f92078aba 100644
--- a/tools/perf/builtin-kvm.c
+++ b/tools/perf/builtin-kvm.c
@@ -20,7 +20,9 @@
#include "util/data.h"

#include <sys/prctl.h>
+#ifdef HAVE_TIMERFD_SUPPORT
#include <sys/timerfd.h>
+#endif

#include <termios.h>
#include <semaphore.h>
@@ -337,6 +339,7 @@ static void init_kvm_event_record(struct perf_kvm_stat *kvm)
INIT_LIST_HEAD(&kvm->kvm_events_cache[i]);
}

+#ifdef HAVE_TIMERFD_SUPPORT
static void clear_events_cache_stats(struct list_head *kvm_events_cache)
{
struct list_head *head;
@@ -358,6 +361,7 @@ static void clear_events_cache_stats(struct list_head *kvm_events_cache)
}
}
}
+#endif

static int kvm_events_hash_fn(u64 key)
{
@@ -783,6 +787,7 @@ static void print_result(struct perf_kvm_stat *kvm)
pr_info("\nLost events: %" PRIu64 "\n\n", kvm->lost_events);
}

+#ifdef HAVE_TIMERFD_SUPPORT
static int process_lost_event(struct perf_tool *tool,
union perf_event *event __maybe_unused,
struct perf_sample *sample __maybe_unused,
@@ -793,6 +798,7 @@ static int process_lost_event(struct perf_tool *tool,
kvm->lost_events++;
return 0;
}
+#endif

static bool skip_sample(struct perf_kvm_stat *kvm,
struct perf_sample *sample)
@@ -872,6 +878,7 @@ static bool verify_vcpu(int vcpu)
return true;
}

+#ifdef HAVE_TIMERFD_SUPPORT
/* keeping the max events to a modest level to keep
* the processing of samples per mmap smooth.
*/
@@ -1213,6 +1220,7 @@ static int kvm_live_open_events(struct perf_kvm_stat *kvm)
out:
return rc;
}
+#endif

static int read_events(struct perf_kvm_stat *kvm)
{
@@ -1379,6 +1387,7 @@ kvm_events_report(struct perf_kvm_stat *kvm, int argc, const char **argv)
return kvm_events_report_vcpu(kvm);
}

+#ifdef HAVE_TIMERFD_SUPPORT
static struct perf_evlist *kvm_live_event_list(void)
{
struct perf_evlist *evlist;
@@ -1566,6 +1575,7 @@ out:

return err;
}
+#endif

static void print_kvm_stat_usage(void)
{
@@ -1604,8 +1614,10 @@ static int kvm_cmd_stat(const char *file_name, int argc, const char **argv)
if (!strncmp(argv[1], "rep", 3))
return kvm_events_report(&kvm, argc - 1 , argv + 1);

+#ifdef HAVE_TIMERFD_SUPPORT
if (!strncmp(argv[1], "live", 4))
return kvm_events_live(&kvm, argc - 1 , argv + 1);
+#endif

perf_stat:
return cmd_stat(argc, argv, NULL);
diff --git a/tools/perf/config/Makefile b/tools/perf/config/Makefile
index c82772207e6e..afe4945e3e84 100644
--- a/tools/perf/config/Makefile
+++ b/tools/perf/config/Makefile
@@ -395,6 +395,13 @@ else
endif
endif

+$(call feature_check,timerfd)
+ifeq ($(feature-timerfd), 1)
+ CFLAGS += -DHAVE_TIMERFD_SUPPORT
+else
+ msg := $(warning No timerfd support. Disables 'perf kvm stat live');
+endif
+
disable-python = $(eval $(disable-python_code))
define disable-python_code
CFLAGS += -DNO_LIBPYTHON
diff --git a/tools/perf/config/feature-checks/Makefile b/tools/perf/config/feature-checks/Makefile
index 452b67cc4d7b..a4d4173c576e 100644
--- a/tools/perf/config/feature-checks/Makefile
+++ b/tools/perf/config/feature-checks/Makefile
@@ -25,7 +25,8 @@ FILES= \
test-libunwind \
test-on-exit \
test-stackprotector-all \
- test-stackprotector
+ test-stackprotector \
+ test-timerfd

CC := $(CC) -MD

@@ -136,6 +137,9 @@ test-on-exit:
test-backtrace:
$(BUILD)

+test-timerfd:
+ $(BUILD)
+
-include *.d

###############################
diff --git a/tools/perf/config/feature-checks/test-all.c b/tools/perf/config/feature-checks/test-all.c
index 50d431892a0c..59e7a705e146 100644
--- a/tools/perf/config/feature-checks/test-all.c
+++ b/tools/perf/config/feature-checks/test-all.c
@@ -81,6 +81,10 @@
# include "test-libnuma.c"
#undef main

+#define main main_test_timerfd
+# include "test-timerfd.c"
+#undef main
+
int main(int argc, char *argv[])
{
main_test_libpython();
@@ -101,6 +105,7 @@ int main(int argc, char *argv[])
main_test_on_exit();
main_test_backtrace();
main_test_libnuma();
+ main_test_timerfd();

return 0;
}
diff --git a/tools/perf/config/feature-checks/test-timerfd.c b/tools/perf/config/feature-checks/test-timerfd.c
new file mode 100644
index 000000000000..8c5c083b4d3c
--- /dev/null
+++ b/tools/perf/config/feature-checks/test-timerfd.c
@@ -0,0 +1,18 @@
+/*
+ * test for timerfd functions used by perf-kvm-stat-live
+ */
+#include <sys/timerfd.h>
+
+int main(void)
+{
+ struct itimerspec new_value;
+
+ int fd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK);
+ if (fd < 0)
+ return 1;
+
+ if (timerfd_settime(fd, 0, &new_value, NULL) != 0)
+ return 1;
+
+ return 0;
+}
--
1.7.12.4 (Apple Git-37)

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