Reference timestamp is added to perf header to allow conversion of kernel timestamps to time-of-day. Timestamp is added using a feature bit for compatibility with older binaries.
Signed-off-by: David Ahern <[email protected]> --- tools/perf/util/header.c | 51 +++++++++++++++++++++++++++++++++++++++++++++ tools/perf/util/header.h | 3 ++ tools/perf/util/session.c | 26 +++++++++++++++++++++++ 3 files changed, 80 insertions(+), 0 deletions(-) diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index f65d7dc..0f04368 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -191,6 +191,40 @@ static int write_padded(int fd, const void *bf, size_t count, return err; } +static int perf_header__read_ref_time(struct perf_header *self, + int fd, u64 offset, u64 size) +{ + size_t sz_nsec = sizeof(self->nsec_ref); + size_t sz_tv = sizeof(self->tv_ref); + int err = -1; + + if (((size - offset) < (sz_nsec + sz_tv)) || + (read(fd, &self->nsec_ref, sz_nsec) != (ssize_t) sz_nsec) || + (read(fd, &self->tv_ref, sz_tv) != (ssize_t) sz_tv)) + goto out; + + err = 0; + +out: + return err; +} + +static int perf_header__write_ref_time(struct perf_header *self, int fd) +{ + size_t sz_nsec = sizeof(self->nsec_ref); + size_t sz_tv = sizeof(self->tv_ref); + int err = -1; + + if ((write(fd, &self->nsec_ref, sz_nsec) != (ssize_t) sz_nsec) || + (write(fd, &self->tv_ref, sz_tv) != (ssize_t) sz_tv)) + goto out; + + err = 0; + +out: + return err; +} + #define dsos__for_each_with_build_id(pos, head) \ list_for_each_entry(pos, head, node) \ if (!pos->has_build_id) \ @@ -483,6 +517,19 @@ static int perf_header__adds_write(struct perf_header *self, int fd) perf_session__cache_build_ids(session); } + if (perf_header__has_feat(self, HEADER_REFERENCE_TIME)) { + struct perf_file_section *tref_sec; + + tref_sec = &feat_sec[idx++]; + tref_sec->offset = lseek(fd, 0, SEEK_CUR); + err = perf_header__write_ref_time(self, fd); + if (err < 0) { + pr_debug("failed to write reference time\n"); + goto out_free; + } + tref_sec->size = lseek(fd, 0, SEEK_CUR) - tref_sec->offset; + } + lseek(fd, sec_start, SEEK_SET); err = do_write(fd, feat_sec, sec_size); if (err < 0) @@ -810,6 +857,10 @@ static int perf_file_section__process(struct perf_file_section *self, if (perf_header__read_build_ids(ph, fd, self->offset, self->size)) pr_debug("Failed to read buildids, continuing...\n"); break; + case HEADER_REFERENCE_TIME: + if (perf_header__read_ref_time(ph, fd, self->offset, self->size)) + pr_debug("Failed to read reference time, continuing...\n"); + break; default: pr_debug("unknown feature %d, continuing...\n", feat); } diff --git a/tools/perf/util/header.h b/tools/perf/util/header.h index ed550bf..d1a8e19 100644 --- a/tools/perf/util/header.h +++ b/tools/perf/util/header.h @@ -19,6 +19,7 @@ struct perf_header_attr { enum { HEADER_TRACE_INFO = 1, HEADER_BUILD_ID, + HEADER_REFERENCE_TIME, HEADER_LAST_FEATURE, }; @@ -59,6 +60,8 @@ struct perf_header { u64 data_size; u64 event_offset; u64 event_size; + u64 nsec_ref; + struct timeval tv_ref; DECLARE_BITMAP(adds_features, HEADER_FEAT_BITS); }; diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c index 3ae6955..1ceef22 100644 --- a/tools/perf/util/session.c +++ b/tools/perf/util/session.c @@ -70,6 +70,29 @@ void perf_session__update_sample_type(struct perf_session *self) self->sample_type = perf_header__sample_type(&self->header); } +static int perf_session__create_ref_time(struct perf_session *self) +{ + struct timespec tp; + + /* race here between successive calls, but should be close enough */ + if (gettimeofday(&self->header.tv_ref, NULL) != 0) { + pr_err("gettimeofday failed. Cannot set reference time.\n"); + return -1; + } + + if (clock_gettime(CLOCK_MONOTONIC, &tp) != 0) { + pr_err("clock_gettime failed. Cannot set reference time.\n"); + return -1; + } + + self->header.nsec_ref = (u64) tp.tv_sec * NSEC_PER_SEC + + (u64) tp.tv_nsec; + + perf_header__set_feat(&self->header, HEADER_REFERENCE_TIME); + + return 0; +} + int perf_session__create_kernel_maps(struct perf_session *self) { int ret = machine__create_kernel_maps(&self->host_machine); @@ -117,6 +140,9 @@ struct perf_session *perf_session__new(const char *filename, int mode, bool forc */ if (perf_session__create_kernel_maps(self) < 0) goto out_delete; + + if (perf_session__create_ref_time(self) < 0) + goto out_delete; } perf_session__update_sample_type(self); -- 1.7.2.3 -- To unsubscribe from this list: send the line "unsubscribe linux-perf-users" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
