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perf session: Show branch speculation info in raw dump
authorSandipan Das <sandipan.das@amd.com>
Thu, 2 Feb 2023 12:26:15 +0000 (17:56 +0530)
committerArnaldo Carvalho de Melo <acme@redhat.com>
Thu, 2 Feb 2023 20:18:31 +0000 (17:18 -0300)
Show the branch speculation info if provided by the branch recording
hardware feature. This can be useful for purposes of code optimization.

E.g.

  $ perf record -j any,u ./test_branch
  $ perf report --dump-raw-trace

Before:

  [...]
  8380958377610 0x40b178 [0x1b0]: PERF_RECORD_SAMPLE(IP, 0x2): 7952/7952: 0x4f851a period: 48973 addr: 0
  ... branch stack: nr:16
  .....  0: 00000000004b52fd -> 00000000004f82c0 0 cycles  P   0
  .....  1: ffffffff8220137c -> 00000000004b52f0 0 cycles M    0
  .....  2: 000000000041d1c4 -> 00000000004b52f0 0 cycles  P   0
  .....  3: 00000000004e7ead -> 000000000041d1b0 0 cycles M    0
  .....  4: 00000000004e7f91 -> 00000000004e7ead 0 cycles  P   0
  .....  5: 00000000004e7ea8 -> 00000000004e7f70 0 cycles  P   0
  .....  6: 00000000004e7e52 -> 00000000004e7e98 0 cycles M    0
  .....  7: 00000000004e7e1f -> 00000000004e7e40 0 cycles M    0
  .....  8: 00000000004e7f60 -> 00000000004e7df0 0 cycles  P   0
  .....  9: 00000000004e7f58 -> 00000000004e7f60 0 cycles M    0
  ..... 10: 000000000041d85d -> 00000000004e7f50 0 cycles  P   0
  ..... 11: 000000000043306a -> 000000000041d840 0 cycles  P   0
  ..... 12: ffffffff8220137c -> 0000000000433040 0 cycles M    0
  ..... 13: 000000000041e4a1 -> 0000000000433040 0 cycles  P   0
  ..... 14: ffffffff8220137c -> 000000000041e490 0 cycles M    0
  ..... 15: 000000000041d89b -> 000000000041e487 0 cycles  P   0
   ... thread: test_branch:7952
   ...... dso: /data/sandipan/test_branch
  [...]

After:

  [...]
  8380958377610 0x40b178 [0x1b0]: PERF_RECORD_SAMPLE(IP, 0x2): 7952/7952: 0x4f851a period: 48973 addr: 0
  ... branch stack: nr:16
  .....  0: 00000000004b52fd -> 00000000004f82c0 0 cycles  P   0  NON_SPEC_CORRECT_PATH
  .....  1: ffffffff8220137c -> 00000000004b52f0 0 cycles M    0  NON_SPEC_CORRECT_PATH
  .....  2: 000000000041d1c4 -> 00000000004b52f0 0 cycles  P   0  NON_SPEC_CORRECT_PATH
  .....  3: 00000000004e7ead -> 000000000041d1b0 0 cycles M    0  NON_SPEC_CORRECT_PATH
  .....  4: 00000000004e7f91 -> 00000000004e7ead 0 cycles  P   0  NON_SPEC_CORRECT_PATH
  .....  5: 00000000004e7ea8 -> 00000000004e7f70 0 cycles  P   0  NON_SPEC_CORRECT_PATH
  .....  6: 00000000004e7e52 -> 00000000004e7e98 0 cycles M    0  SPEC_CORRECT_PATH
  .....  7: 00000000004e7e1f -> 00000000004e7e40 0 cycles M    0  NON_SPEC_CORRECT_PATH
  .....  8: 00000000004e7f60 -> 00000000004e7df0 0 cycles  P   0  NON_SPEC_CORRECT_PATH
  .....  9: 00000000004e7f58 -> 00000000004e7f60 0 cycles M    0  NON_SPEC_CORRECT_PATH
  ..... 10: 000000000041d85d -> 00000000004e7f50 0 cycles  P   0  NON_SPEC_CORRECT_PATH
  ..... 11: 000000000043306a -> 000000000041d840 0 cycles  P   0  NON_SPEC_CORRECT_PATH
  ..... 12: ffffffff8220137c -> 0000000000433040 0 cycles M    0  NON_SPEC_CORRECT_PATH
  ..... 13: 000000000041e4a1 -> 0000000000433040 0 cycles  P   0  NON_SPEC_CORRECT_PATH
  ..... 14: ffffffff8220137c -> 000000000041e490 0 cycles M    0  NON_SPEC_CORRECT_PATH
  ..... 15: 000000000041d89b -> 000000000041e487 0 cycles  P   0  NON_SPEC_CORRECT_PATH
   ... thread: test_branch:7952
   ...... dso: /data/sandipan/test_branch
  [...]

With the addition of new branch flags, the "brstacksym" fields in perf
script output now shows speculation information after the branch type.
Change the regular expressions accordingly for the test to pass. Since
branch speculation information may vary across platforms, the test does
not look for specific values.

E.g.

  $ perf test -v 110

Before:

  110: Check branch stack sampling                                     :
  --- start ---
  test child forked, pid 54154
  Testing user branch stack sampling
  + grep -E -m1 ^brstack_bench\+[^ ]*/brstack_foo\+[^ ]*/IND_CALL$ /tmp/__perf_test.program.AfhUI/perf.script
  + cleanup
  + rm -rf /tmp/__perf_test.program.AfhUI
  test child finished with -1
  ---- end ----
  Check branch stack sampling: FAILED!

After:

  110: Check branch stack sampling                                     :
  --- start ---
  test child forked, pid 43716
  Testing user branch stack sampling
  + grep -E -m1 ^brstack_bench\+[^ ]*/brstack_foo\+[^ ]*/IND_CALL/.*$ /tmp/__perf_test.program.xgzAi/perf.script
  brstack_bench+0x66/brstack_foo+0x0/P/-/-/0/IND_CALL/NON_SPEC_CORRECT_PATH
  + grep -E -m1 ^brstack_foo\+[^ ]*/brstack_bar\+[^ ]*/CALL/.*$ /tmp/__perf_test.program.xgzAi/perf.script
  brstack_foo+0x1b/brstack_bar+0x0/P/-/-/0/CALL/NON_SPEC_CORRECT_PATH
  + grep -E -m1 ^brstack_bench\+[^ ]*/brstack_foo\+[^ ]*/CALL/.*$ /tmp/__perf_test.program.xgzAi/perf.script
  brstack_bench+0x58/brstack_foo+0x0/P/-/-/0/CALL/NON_SPEC_CORRECT_PATH
  + grep -E -m1 ^brstack_bench\+[^ ]*/brstack_bar\+[^ ]*/CALL/.*$ /tmp/__perf_test.program.xgzAi/perf.script
  brstack_bench+0x5d/brstack_bar+0x0/P/-/-/0/CALL/NON_SPEC_CORRECT_PATH
  + grep -E -m1 ^brstack_bar\+[^ ]*/brstack_foo\+[^ ]*/RET/.*$ /tmp/__perf_test.program.xgzAi/perf.script
  brstack_bar+0x31/brstack_foo+0x20/P/-/-/0/RET/NON_SPEC_CORRECT_PATH
  + grep -E -m1 ^brstack_foo\+[^ ]*/brstack_bench\+[^ ]*/RET/.*$ /tmp/__perf_test.program.xgzAi/perf.script
  brstack_foo+0x36/brstack_bench+0x5d/P/-/-/0/RET/NON_SPEC_CORRECT_PATH
  + grep -E -m1 ^brstack_bench\+[^ ]*/brstack_bench\+[^ ]*/COND/.*$ /tmp/__perf_test.program.xgzAi/perf.script
  brstack_bench+0x76/brstack_bench+0x7d/P/-/-/0/COND/NON_SPEC_CORRECT_PATH
  + grep -E -m1 ^brstack\+[^ ]*/brstack\+[^ ]*/UNCOND/.*$ /tmp/__perf_test.program.xgzAi/perf.script
  brstack+0x5a/brstack+0x41/P/-/-/0/UNCOND/NON_SPEC_CORRECT_PATH
  + set +x
  Testing branch stack filtering permutation (any_call,CALL|IND_CALL|COND_CALL|SYSCALL|IRQ)
  Testing branch stack filtering permutation (call,CALL|SYSCALL)
  Testing branch stack filtering permutation (cond,COND)
  Testing branch stack filtering permutation (any_ret,RET|COND_RET|SYSRET|ERET)
  Testing branch stack filtering permutation (call,cond,CALL|SYSCALL|COND)
  Testing branch stack filtering permutation (any_call,cond,CALL|IND_CALL|COND_CALL|IRQ|SYSCALL|COND)
  Testing branch stack filtering permutation (cond,any_call,any_ret,COND|CALL|IND_CALL|COND_CALL|SYSCALL|IRQ|RET|COND_RET|SYSRET|ERET)
  test child finished with 0
  ---- end ----
  Check branch stack sampling: Ok

Signed-off-by: Sandipan Das <sandipan.das@amd.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ananth Narayan <ananth.narayan@amd.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Santosh Shukla <santosh.shukla@amd.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: x86@kernel.org
Link: https://lore.kernel.org/r/048d67c9de3cc8e3dbf19aaa7ff718dec91364c5.1675333809.git.sandipan.das@amd.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
tools/perf/tests/shell/test_brstack.sh patch | blob | history
tools/perf/util/session.c patch | blob | history

diff --git a/tools/perf/tests/shell/test_brstack.sh b/tools/perf/tests/shell/test_brstack.sh
index 59195eb..1c49d82 100755 (executable)
--- a/tools/perf/tests/shell/test_brstack.sh
+++ b/tools/perf/tests/shell/test_brstack.sh
@@ -30,14 +30,14 @@ test_user_branches() {
        #       brstack_foo+0x14/brstack_bar+0x40/P/-/-/0/CALL
 
        set -x
-       grep -E -m1 "^brstack_bench\+[^ ]*/brstack_foo\+[^ ]*/IND_CALL$"        $TMPDIR/perf.script
-       grep -E -m1 "^brstack_foo\+[^ ]*/brstack_bar\+[^ ]*/CALL$"      $TMPDIR/perf.script
-       grep -E -m1 "^brstack_bench\+[^ ]*/brstack_foo\+[^ ]*/CALL$"    $TMPDIR/perf.script
-       grep -E -m1 "^brstack_bench\+[^ ]*/brstack_bar\+[^ ]*/CALL$"    $TMPDIR/perf.script
-       grep -E -m1 "^brstack_bar\+[^ ]*/brstack_foo\+[^ ]*/RET$"               $TMPDIR/perf.script
-       grep -E -m1 "^brstack_foo\+[^ ]*/brstack_bench\+[^ ]*/RET$"     $TMPDIR/perf.script
-       grep -E -m1 "^brstack_bench\+[^ ]*/brstack_bench\+[^ ]*/COND$"  $TMPDIR/perf.script
-       grep -E -m1 "^brstack\+[^ ]*/brstack\+[^ ]*/UNCOND$"            $TMPDIR/perf.script
+       grep -E -m1 "^brstack_bench\+[^ ]*/brstack_foo\+[^ ]*/IND_CALL/.*$"     $TMPDIR/perf.script
+       grep -E -m1 "^brstack_foo\+[^ ]*/brstack_bar\+[^ ]*/CALL/.*$"   $TMPDIR/perf.script
+       grep -E -m1 "^brstack_bench\+[^ ]*/brstack_foo\+[^ ]*/CALL/.*$" $TMPDIR/perf.script
+       grep -E -m1 "^brstack_bench\+[^ ]*/brstack_bar\+[^ ]*/CALL/.*$" $TMPDIR/perf.script
+       grep -E -m1 "^brstack_bar\+[^ ]*/brstack_foo\+[^ ]*/RET/.*$"            $TMPDIR/perf.script
+       grep -E -m1 "^brstack_foo\+[^ ]*/brstack_bench\+[^ ]*/RET/.*$"  $TMPDIR/perf.script
+       grep -E -m1 "^brstack_bench\+[^ ]*/brstack_bench\+[^ ]*/COND/.*$"       $TMPDIR/perf.script
+       grep -E -m1 "^brstack\+[^ ]*/brstack\+[^ ]*/UNCOND/.*$"         $TMPDIR/perf.script
        set +x
 
        # some branch types are still not being tested:
@@ -57,7 +57,7 @@ test_filter() {
 
        # fail if we find any branch type that doesn't match any of the expected ones
        # also consider UNKNOWN branch types (-)
-       if grep -E -vm1 "^[^ ]*/($expect|-|( *))$" $TMPDIR/perf.script; then
+       if grep -E -vm1 "^[^ ]*/($expect|-|( *))/.*$" $TMPDIR/perf.script; then
                return 1
        fi
 }
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index fdfe772..749d5b5 100644 (file)
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -1180,7 +1180,7 @@ 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 %s\n",
+                       printf("..... %2"PRIu64": %016" PRIx64 " -> %016" PRIx64 " %hu cycles %s%s%s%s %x %s %s\n",
                                i, e->from, e->to,
                                (unsigned short)e->flags.cycles,
                                e->flags.mispred ? "M" : " ",
@@ -1188,7 +1188,8 @@ static void branch_stack__printf(struct perf_sample *sample, bool callstack)
                                e->flags.abort ? "A" : " ",
                                e->flags.in_tx ? "T" : " ",
                                (unsigned)e->flags.reserved,
-                               get_branch_type(e));
+                               get_branch_type(e),
+                               e->flags.spec ? branch_spec_desc(e->flags.spec) : "");
                } else {
                        if (i == 0) {
                                printf("..... %2"PRIu64": %016" PRIx64 "\n"
Domain: System / Kernel;