Messages in this thread | | | Date | Tue, 8 Mar 2022 11:58:27 +0000 | Subject | Re: [PATCH 2/4] perf: Print branch stack entry type in --dump-raw-trace | From | James Clark <> |
| |
On 08/03/2022 04:29, Anshuman Khandual wrote: > > > On 3/7/22 22:49, James Clark wrote: >> This can help with debugging issues. It only prints when -j save_type >> is used otherwise an empty string is printed. > > Specifying events with PERF_SAMPLE_BRANCH_CALL_STACK flag explicitly might > be better along with '-j save_type'. > >> >> Before the change: >> >> 101603801707130 0xa70 [0x630]: PERF_RECORD_SAMPLE(IP, 0x2): 1108/1108: 0xffff9c1df24c period: 10694 addr: 0 >> ... branch stack: nr:64 >> ..... 0: 0000ffff9c26029c -> 0000ffff9c26f340 0 cycles P 0 >> ..... 1: 0000ffff9c2601bc -> 0000ffff9c26f340 0 cycles P 0 >> >> After the change: >> >> 101603801707130 0xa70 [0x630]: PERF_RECORD_SAMPLE(IP, 0x2): 1108/1108: 0xffff9c1df24c period: 10694 addr: 0 >> ... branch stack: nr:64 >> ..... 0: 0000ffff9c26029c -> 0000ffff9c26f340 0 cycles P 0 CALL >> ..... 1: 0000ffff9c2601bc -> 0000ffff9c26f340 0 cycles P 0 IND_CALL >> >> Signed-off-by: James Clark <james.clark@arm.com> >> --- >> tools/perf/util/session.c | 5 +++-- >> 1 file changed, 3 insertions(+), 2 deletions(-) >> >> diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c >> index f54282d5c648..3b8dfe603e50 100644 >> --- a/tools/perf/util/session.c >> +++ b/tools/perf/util/session.c >> @@ -1159,14 +1159,15 @@ static void branch_stack__printf(struct perf_sample *sample, bool callstack) >> struct branch_entry *e = &entries[i]; >> >> if (!callstack) { >> - printf("..... %2"PRIu64": %016" PRIx64 " -> %016" PRIx64 " %hu cycles %s%s%s%s %x\n", >> + printf("..... %2"PRIu64": %016" PRIx64 " -> %016" PRIx64 " %hu cycles %s%s%s%s %x %s\n", >> i, e->from, e->to, >> (unsigned short)e->flags.cycles, >> e->flags.mispred ? "M" : " ", >> e->flags.predicted ? "P" : " ", >> e->flags.abort ? "A" : " ", >> e->flags.in_tx ? "T" : " ", >> - (unsigned)e->flags.reserved); >> + (unsigned)e->flags.reserved, >> + e->flags.type ? branch_type_name(e->flags.type) : ""); >> } else { >> printf("..... %2"PRIu64": %016" PRIx64 "\n", >> i, i > 0 ? e->from : e->to); > > LGTM but I am wondering whether this might affect existing tools ?
Only humans should be reading the -D output so I don't think so. The format is not very parseable anyway
| |