CoreSight January 2019

coresight@lists.linaro.org

9 participants
12 discussions

[PATCH AUTOSEL 4.19 77/97] perf cs-etm: Correct packets swapping in cs_etm__flush()

by Sasha Levin

From: Leo Yan <leo.yan(a)linaro.org> [ Upstream commit 43fd56669c28cd354e9228bdb58e4bca1c1a8b66 ] The structure cs_etm_queue uses 'prev_packet' to point to previous packet, this can be used to combine with new coming packet to generate samples. In function cs_etm__flush() it swaps packets only when the flag 'etm->synth_opts.last_branch' is true, this means that it will not swap packets if without option '--itrace=il' to generate last branch entries; thus for this case the 'prev_packet' doesn't point to the correct previous packet and the stale packet still will be used to generate sequential sample. Thus if dump trace with 'perf script' command we can see the incorrect flow with the stale packet's address info. This patch corrects packets swapping in cs_etm__flush(); except using the flag 'etm->synth_opts.last_branch' it also checks the another flag 'etm->sample_branches', if any flag is true then it swaps packets so can save correct content to 'prev_packet'. Finally this can fix the wrong program flow dumping issue. The patch has a minor refactoring to use 'etm->synth_opts.last_branch' instead of 'etmq->etm->synth_opts.last_branch' for condition checking, this is consistent with that is done in cs_etm__sample(). Signed-off-by: Leo Yan <leo.yan(a)linaro.org> Reviewed-by: Mathieu Poirier <mathieu.poirier(a)linaro.org> Cc: Alexander Shishkin <alexander.shishkin(a)linux.intel.com> Cc: Jiri Olsa <jolsa(a)redhat.com> Cc: Mike Leach <mike.leach(a)linaro.org> Cc: Namhyung Kim <namhyung(a)kernel.org> Cc: Robert Walker <robert.walker(a)arm.com> Cc: coresight(a)lists.linaro.org Cc: linux-arm-kernel(a)lists.infradead.org Link: http://lkml.kernel.org/r/1544513908-16805-2-git-send-email-leo.yan@linaro.o… Signed-off-by: Arnaldo Carvalho de Melo <acme(a)redhat.com> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- tools/perf/util/cs-etm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c index ca577658e890..7b5e15cc6b71 100644 --- a/tools/perf/util/cs-etm.c +++ b/tools/perf/util/cs-etm.c @@ -1005,7 +1005,7 @@ static int cs_etm__flush(struct cs_etm_queue *etmq) } swap_packet: - if (etmq->etm->synth_opts.last_branch) { + if (etm->sample_branches || etm->synth_opts.last_branch) { /* * Swap PACKET with PREV_PACKET: PACKET becomes PREV_PACKET for * the next incoming packet. -- 2.19.1

7 years, 8 months

[PATCH AUTOSEL 4.20 093/117] perf cs-etm: Correct packets swapping in cs_etm__flush()

by Sasha Levin

From: Leo Yan <leo.yan(a)linaro.org> [ Upstream commit 43fd56669c28cd354e9228bdb58e4bca1c1a8b66 ] The structure cs_etm_queue uses 'prev_packet' to point to previous packet, this can be used to combine with new coming packet to generate samples. In function cs_etm__flush() it swaps packets only when the flag 'etm->synth_opts.last_branch' is true, this means that it will not swap packets if without option '--itrace=il' to generate last branch entries; thus for this case the 'prev_packet' doesn't point to the correct previous packet and the stale packet still will be used to generate sequential sample. Thus if dump trace with 'perf script' command we can see the incorrect flow with the stale packet's address info. This patch corrects packets swapping in cs_etm__flush(); except using the flag 'etm->synth_opts.last_branch' it also checks the another flag 'etm->sample_branches', if any flag is true then it swaps packets so can save correct content to 'prev_packet'. Finally this can fix the wrong program flow dumping issue. The patch has a minor refactoring to use 'etm->synth_opts.last_branch' instead of 'etmq->etm->synth_opts.last_branch' for condition checking, this is consistent with that is done in cs_etm__sample(). Signed-off-by: Leo Yan <leo.yan(a)linaro.org> Reviewed-by: Mathieu Poirier <mathieu.poirier(a)linaro.org> Cc: Alexander Shishkin <alexander.shishkin(a)linux.intel.com> Cc: Jiri Olsa <jolsa(a)redhat.com> Cc: Mike Leach <mike.leach(a)linaro.org> Cc: Namhyung Kim <namhyung(a)kernel.org> Cc: Robert Walker <robert.walker(a)arm.com> Cc: coresight(a)lists.linaro.org Cc: linux-arm-kernel(a)lists.infradead.org Link: http://lkml.kernel.org/r/1544513908-16805-2-git-send-email-leo.yan@linaro.o… Signed-off-by: Arnaldo Carvalho de Melo <acme(a)redhat.com> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- tools/perf/util/cs-etm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c index 73430b73570d..c2f0c92623f0 100644 --- a/tools/perf/util/cs-etm.c +++ b/tools/perf/util/cs-etm.c @@ -1005,7 +1005,7 @@ static int cs_etm__flush(struct cs_etm_queue *etmq) } swap_packet: - if (etmq->etm->synth_opts.last_branch) { + if (etm->sample_branches || etm->synth_opts.last_branch) { /* * Swap PACKET with PREV_PACKET: PACKET becomes PREV_PACKET for * the next incoming packet. -- 2.19.1

7 years, 8 months

2026

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

CoreSight January 2019