The event PERF_RECORD_TIME_CONV was extended for clock parameters, but
the tool fails to be backwards-compatible for the old event format.
Based on checking the event size, this patch series can decide if the
extended clock parameters are contained in the perf event or not. This
allows the event PERF_RECORD_TIME_CONV to be backwards-compatible.
The last patch also is introduced for dumping the event, for both the
old and latest event formats.
The patch set has been rebased on perf/core branch with:
commit 4c391ea001cb ("perf beauty: Fix fsconfig generator")
And the patches have been tested on Arm64 HiSilicon D06 platform.
Changes from v2:
* Fixed subject and commit log in patch 01.
Changes from v1:
* Changed from bool to __u8 for perf_record_time_conv (Adrain);
* Added helper event_contains() and used it (Adrian).
Leo Yan (4):
perf tool: Change fields type in perf_record_time_conv
perf jit: Let convert_timestamp() to be backwards-compatible
perf session: Add swap operation for event TIME_CONV
perf session: Dump PERF_RECORD_TIME_CONV event
tools/lib/perf/include/perf/event.h | 7 +++++--
tools/perf/util/jitdump.c | 30 +++++++++++++++++++----------
tools/perf/util/session.c | 28 +++++++++++++++++++++++++--
tools/perf/util/tsc.c | 30 +++++++++++++++++++++++++++++
tools/perf/util/tsc.h | 4 ++++
5 files changed, 85 insertions(+), 14 deletions(-)
--
2.25.1
Commit d110162cafc8 ("perf tsc: Support cap_user_time_short for event
TIME_CONV") supports the extended parameters for event TIME_CONV, but it
broke the backwards compatibility, so any perf data file with old event
format fails to convert timestamp.
This patch introduces a helper event_contains() to checks if an event
contains a specific member or not. For the backwards-compatibility, if
the event size confirms the extended parameters are supported in the
event TIME_CONV, then copies these parameters.
Fixes: d110162cafc8 ("perf tsc: Support cap_user_time_short for event TIME_CONV")
Signed-off-by: Leo Yan <[email protected]>
Acked-by: Adrian Hunter <[email protected]>
---
tools/lib/perf/include/perf/event.h | 2 ++
tools/perf/util/jitdump.c | 30 +++++++++++++++++++----------
2 files changed, 22 insertions(+), 10 deletions(-)
diff --git a/tools/lib/perf/include/perf/event.h b/tools/lib/perf/include/perf/event.h
index 48583e441d9b..4d0c02ba3f7d 100644
--- a/tools/lib/perf/include/perf/event.h
+++ b/tools/lib/perf/include/perf/event.h
@@ -8,6 +8,8 @@
#include <linux/bpf.h>
#include <sys/types.h> /* pid_t */
+#define event_contains(obj, mem) ((obj).header.size > offsetof(typeof(obj), mem))
+
struct perf_record_mmap {
struct perf_event_header header;
__u32 pid, tid;
diff --git a/tools/perf/util/jitdump.c b/tools/perf/util/jitdump.c
index 9760d8e7b386..5d388622b7ac 100644
--- a/tools/perf/util/jitdump.c
+++ b/tools/perf/util/jitdump.c
@@ -396,21 +396,31 @@ static pid_t jr_entry_tid(struct jit_buf_desc *jd, union jr_entry *jr)
static uint64_t convert_timestamp(struct jit_buf_desc *jd, uint64_t timestamp)
{
- struct perf_tsc_conversion tc;
+ struct perf_tsc_conversion tc = { 0 };
+ struct perf_record_time_conv *time_conv = &jd->session->time_conv;
if (!jd->use_arch_timestamp)
return timestamp;
- tc.time_shift = jd->session->time_conv.time_shift;
- tc.time_mult = jd->session->time_conv.time_mult;
- tc.time_zero = jd->session->time_conv.time_zero;
- tc.time_cycles = jd->session->time_conv.time_cycles;
- tc.time_mask = jd->session->time_conv.time_mask;
- tc.cap_user_time_zero = jd->session->time_conv.cap_user_time_zero;
- tc.cap_user_time_short = jd->session->time_conv.cap_user_time_short;
+ tc.time_shift = time_conv->time_shift;
+ tc.time_mult = time_conv->time_mult;
+ tc.time_zero = time_conv->time_zero;
- if (!tc.cap_user_time_zero)
- return 0;
+ /*
+ * The event TIME_CONV was extended for the fields from "time_cycles"
+ * when supported cap_user_time_short, for backward compatibility,
+ * checks the event size and assigns these extended fields if these
+ * fields are contained in the event.
+ */
+ if (event_contains(*time_conv, time_cycles)) {
+ tc.time_cycles = time_conv->time_cycles;
+ tc.time_mask = time_conv->time_mask;
+ tc.cap_user_time_zero = time_conv->cap_user_time_zero;
+ tc.cap_user_time_short = time_conv->cap_user_time_short;
+
+ if (!tc.cap_user_time_zero)
+ return 0;
+ }
return tsc_to_perf_time(timestamp, &tc);
}
--
2.25.1