perf script: Enable printing of branch stack

This patch improves perf script by enabling printing of the
branch stack via the 'brstack' and 'brstacksym' arguments to
the field selection option -F. The option is off by default
and operates only if the perf.data file has branch stack content.

The branches are printed in to/from pairs. The most recent branch
is printed first. The number of branch entries vary based on the
underlying hardware and filtering used.

The brstack prints FROM/TO addresses in raw hexadecimal format.
The brstacksym prints FROM/TO addresses in symbolic form wherever
possible.

 $ perf script -F ip,brstack
  5d3000 0x401aa0/0x5d2000/M/-/-/-/0 ...

 $ perf script -F ip,brstacksym
  4011e0 noploop+0x0/noploop+0x0/P/-/-/0

The notation F/T/M/X/A/C describes the attributes of the branch.
F=from, T=to, M/P=misprediction/prediction, X=TSX, A=TSX abort, C=cycles (SKL)

Signed-off-by: Stephane Eranian <eranian@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Yuanfang Chen <cyfmxc@gmail.com>
Link: http://lkml.kernel.org/r/1441039273-16260-5-git-send-email-eranian@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Stephane Eranian
2015-08-31 18:41:13 +02:00
committed by Arnaldo Carvalho de Melo
parent 729a78417a
commit dc323ce8e7
2 changed files with 93 additions and 3 deletions

View File

@@ -112,11 +112,11 @@ OPTIONS
--debug-mode::
Do various checks like samples ordering and lost events.
-f::
-F::
--fields::
Comma separated list of fields to print. Options are:
comm, tid, pid, time, cpu, event, trace, ip, sym, dso, addr, symoff,
srcline, period, iregs, flags.
srcline, period, iregs, brstack, brstacksym, flags.
Field list can be prepended with the type, trace, sw or hw,
to indicate to which event type the field list applies.
e.g., -f sw:comm,tid,time,ip,sym and -f trace:time,cpu,trace
@@ -175,6 +175,16 @@ OPTIONS
Finally, a user may not set fields to none for all event types.
i.e., -f "" is not allowed.
The brstack output includes branch related information with raw addresses using the
/v/v/v/v/ syntax in the following order:
FROM: branch source instruction
TO : branch target instruction
M/P/-: M=branch target mispredicted or branch direction was mispredicted, P=target predicted or direction predicted, -=not supported
X/- : X=branch inside a transactional region, -=not in transaction region or not supported
A/- : A=TSX abort entry, -=not aborted region or not supported
The brstacksym is identical to brstack, except that the FROM and TO addresses are printed in a symbolic form if possible.
-k::
--vmlinux=<file>::
vmlinux pathname