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From: Adrian Hunter <adrian.hunter@intel.com>
To: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>, Andi Kleen <ak@linux.intel.com>,
	linux-kernel@vger.kernel.org
Subject: [PATCH V2 02/12] perf intel-pt: Fix duplicate branch after CBR
Date: Fri, 10 Jul 2020 18:10:54 +0300	[thread overview]
Message-ID: <20200710151104.15137-3-adrian.hunter@intel.com> (raw)
In-Reply-To: <20200710151104.15137-1-adrian.hunter@intel.com>

CBR events can result in a duplicate branch event, because the state type
defaults to a branch. Fix by clearing the state type.

Example: trace 'sleep' and hope for a frequency change

 Before:

   $ perf record -e intel_pt//u sleep 0.1
   [ perf record: Woken up 1 times to write data ]
   [ perf record: Captured and wrote 0.034 MB perf.data ]
   $ perf script --itrace=bpe > before.txt

 After:

   $ perf script --itrace=bpe > after.txt
   $ diff -u before.txt after.txt
   --- before.txt  2020-07-07 14:42:18.191508098 +0300
   +++ after.txt   2020-07-07 14:42:36.587891753 +0300
   @@ -29673,7 +29673,6 @@
               sleep 93431 [007] 15411.619905:          1  branches:u:                 0 [unknown] ([unknown]) =>     7f0818abb2e0 clock_nanosleep@@GLIBC_2.17+0x0 (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
               sleep 93431 [007] 15411.619905:          1  branches:u:      7f0818abb30c clock_nanosleep@@GLIBC_2.17+0x2c (/usr/lib/x86_64-linux-gnu/libc-2.31.so) =>                0 [unknown] ([unknown])
               sleep 93431 [007] 15411.720069:         cbr:  cbr: 15 freq: 1507 MHz ( 56%)         7f0818abb30c clock_nanosleep@@GLIBC_2.17+0x2c (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
   -           sleep 93431 [007] 15411.720069:          1  branches:u:      7f0818abb30c clock_nanosleep@@GLIBC_2.17+0x2c (/usr/lib/x86_64-linux-gnu/libc-2.31.so) =>                0 [unknown] ([unknown])
               sleep 93431 [007] 15411.720076:          1  branches:u:                 0 [unknown] ([unknown]) =>     7f0818abb30e clock_nanosleep@@GLIBC_2.17+0x2e (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
               sleep 93431 [007] 15411.720077:          1  branches:u:      7f0818abb323 clock_nanosleep@@GLIBC_2.17+0x43 (/usr/lib/x86_64-linux-gnu/libc-2.31.so) =>     7f0818ac0eb7 __nanosleep+0x17 (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
               sleep 93431 [007] 15411.720077:          1  branches:u:      7f0818ac0ebf __nanosleep+0x1f (/usr/lib/x86_64-linux-gnu/libc-2.31.so) =>     55cb7e4c2827 rpl_nanosleep+0x97 (/usr/bin/sleep)

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Fixes: 91de8684f1cff ("perf intel-pt: Cater for CBR change in PSB+")
Fixes: abe5a1d3e4bee ("perf intel-pt: Decoder to output CBR changes immediately")
Cc: stable@vger.kernel.org
---
 tools/perf/util/intel-pt-decoder/intel-pt-decoder.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
index 75c4bd74d521..7ffcbd6fcd1a 100644
--- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
+++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
@@ -1977,8 +1977,10 @@ static int intel_pt_walk_trace(struct intel_pt_decoder *decoder)
 			 * possibility of another CBR change that gets caught up
 			 * in the PSB+.
 			 */
-			if (decoder->cbr != decoder->cbr_seen)
+			if (decoder->cbr != decoder->cbr_seen) {
+				decoder->state.type = 0;
 				return 0;
+			}
 			break;
 
 		case INTEL_PT_PIP:
@@ -2019,8 +2021,10 @@ static int intel_pt_walk_trace(struct intel_pt_decoder *decoder)
 
 		case INTEL_PT_CBR:
 			intel_pt_calc_cbr(decoder);
-			if (decoder->cbr != decoder->cbr_seen)
+			if (decoder->cbr != decoder->cbr_seen) {
+				decoder->state.type = 0;
 				return 0;
+			}
 			break;
 
 		case INTEL_PT_MODE_EXEC:
-- 
2.17.1


  parent reply	other threads:[~2020-07-10 15:13 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-10 15:10 [PATCH V2 00/12] perf intel-pt: Add support for decoding FUP/TIP only Adrian Hunter
2020-07-10 15:10 ` [PATCH V2 01/12] perf intel-pt: Fix FUP packet state Adrian Hunter
2020-07-10 15:10 ` Adrian Hunter [this message]
2020-07-10 15:10 ` [PATCH V2 03/12] perf tools: Improve aux_output not supported error Adrian Hunter
2020-07-10 15:10 ` [PATCH V2 04/12] perf auxtrace: Add missing itrace options to help text Adrian Hunter
2020-07-10 15:10 ` [PATCH V2 05/12] perf auxtrace: Add optional error flags to the itrace 'e' option Adrian Hunter
2020-07-10 15:10 ` [PATCH V2 06/12] perf intel-pt: Use itrace error flags to suppress some errors Adrian Hunter
2020-07-10 15:10 ` [PATCH V2 07/12] perf auxtrace: Add optional log flags to the itrace 'd' option Adrian Hunter
2020-07-10 15:11 ` [PATCH V2 08/12] perf intel-pt: Use itrace debug log flags to suppress some messages Adrian Hunter
2020-07-10 15:11 ` [PATCH V2 09/12] perf intel-pt: Time filter logged perf events Adrian Hunter
2020-07-10 15:11 ` [PATCH V2 10/12] perf auxtrace: Add itrace 'q' option for quicker, less detailed decoding Adrian Hunter
2020-07-20 22:27   ` Andi Kleen
2020-07-10 15:11 ` [PATCH V2 11/12] perf intel-pt: Add support for decoding FUP/TIP only Adrian Hunter
2020-07-10 15:11 ` [PATCH V2 12/12] perf intel-pt: Add support for decoding PSB+ only Adrian Hunter
2020-07-20 22:25   ` Andi Kleen
2020-08-06 12:03     ` Arnaldo Carvalho de Melo
2020-08-04 13:34 ` [PATCH V2 00/12] perf intel-pt: Add support for decoding FUP/TIP only Adrian Hunter
2020-08-04 14:59   ` Arnaldo Carvalho de Melo

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