From mboxrd@z Thu Jan 1 00:00:00 1970 From: mike.leach@linaro.org (Mike Leach) Date: Mon, 20 Mar 2017 20:36:18 +0000 Subject: [PATCH] documentation: trace: Clarification of perf usage with coresight. Message-ID: <1490042178-2547-1-git-send-email-mike.leach@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Update to the coresight.txt documentation to clarify the specification of the trace sink when using 'perf record' Signed-off-by: Mike Leach --- Documentation/trace/coresight.txt | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/Documentation/trace/coresight.txt b/Documentation/trace/coresight.txt index d1033aa..e8af562 100644 --- a/Documentation/trace/coresight.txt +++ b/Documentation/trace/coresight.txt @@ -243,6 +243,12 @@ linaro at linaro-nano:~$ perf record -e cs_etm//u --per-thread linaro at linaro-nano:~$ perf record -C 0,2-3 -e cs_etm//k +Note that after a trace run, the sink will be disabled, so it must be +re-enabled before the next 'perf record' command is executed. +Alternatively the sink may be specified as part of the perf command line: + +linaro at linaro-nano:~$ perf record -e cs_etm/@20010000.etb/u --per-thread + As of this writing two ETM/PTM specific options have are available: cycle accurate and timestamp (please refer to the Embedded Trace Macrocell reference manual for details on these options). By default both are disabled but using -- 2.7.4