From: Leo Yan <leo.yan@linaro.org>
To: Arnaldo Carvalho de Melo <acme@kernel.org>,
Adrian Hunter <adrian.hunter@intel.com>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
Mark Rutland <mark.rutland@arm.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>,
Ian Rogers <irogers@google.com>,
Steve MacLean <Steve.MacLean@Microsoft.com>,
Yonatan Goldschmidt <yonatan.goldschmidt@granulate.io>,
"Gustavo A. R. Silva" <gustavoars@kernel.org>,
Kan Liang <kan.liang@linux.intel.com>,
linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Leo Yan <leo.yan@linaro.org>
Subject: [PATCH v2 2/4] perf jit: Let convert_timestamp() to be backwards-compatible
Date: Wed, 28 Apr 2021 19:57:47 +0800 [thread overview]
Message-ID: <20210428115749.5229-3-leo.yan@linaro.org> (raw)
In-Reply-To: <20210428115749.5229-1-leo.yan@linaro.org>
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 <leo.yan@linaro.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
---
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
next prev parent reply other threads:[~2021-04-28 11:58 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-28 11:57 [PATCH v2 0/4] perf: Allow TIME_CONV to be backwards-compatible and dump it Leo Yan
2021-04-28 11:57 ` [PATCH v2 1/4] perf tool: Change fields type in cap_user_time_short Leo Yan
2021-04-28 11:57 ` Leo Yan [this message]
2021-04-28 11:57 ` [PATCH v2 3/4] perf session: Add swap operation for event TIME_CONV Leo Yan
2021-04-28 11:57 ` [PATCH v2 4/4] perf session: Dump PERF_RECORD_TIME_CONV event Leo Yan
2021-04-28 12:10 ` [PATCH v2 0/4] perf: Allow TIME_CONV to be backwards-compatible and dump it Leo Yan
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