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| -rw-r--r-- | Documentation/trace/coresight/coresight.rst | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/Documentation/trace/coresight/coresight.rst b/Documentation/trace/coresight/coresight.rst index 1644a0244ad1..5e76bfe69b0b 100644 --- a/Documentation/trace/coresight/coresight.rst +++ b/Documentation/trace/coresight/coresight.rst @@ -339,7 +339,8 @@ Preference is given to the former as using the sysFS interface requires a deep understanding of the Coresight HW. The following sections provide details on using both methods. -1) Using the sysFS interface: +Using the sysFS interface +~~~~~~~~~~~~~~~~~~~~~~~~~ Before trace collection can start, a coresight sink needs to be identified. There is no limit on the amount of sinks (nor sources) that can be enabled at @@ -446,7 +447,8 @@ wealth of possibilities that coresight provides. Instruction 0 0x8026B588 E8BD8000 true LDM sp!,{pc} Timestamp Timestamp: 17107041535 -2) Using perf framework: +Using perf framework +~~~~~~~~~~~~~~~~~~~~ Coresight tracers are represented using the Perf framework's Performance Monitoring Unit (PMU) abstraction. As such the perf framework takes charge of @@ -495,7 +497,11 @@ More information on the above and other example on how to use Coresight with the perf tools can be found in the "HOWTO.md" file of the openCSD gitHub repository [#third]_. -2.1) AutoFDO analysis using the perf tools: +Advanced perf framework usage +----------------------------- + +AutoFDO analysis using the perf tools +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ perf can be used to record and analyze trace of programs. @@ -513,7 +519,8 @@ The --itrace option controls the type and frequency of synthesized events Note that only 64-bit programs are currently supported - further work is required to support instruction decode of 32-bit Arm programs. -2.2) Tracing PID +Tracing PID +~~~~~~~~~~~ The kernel can be built to write the PID value into the PE ContextID registers. For a kernel running at EL1, the PID is stored in CONTEXTIDR_EL1. A PE may @@ -547,7 +554,7 @@ wants to trace PIDs for both host and guest, the two configs "contextid1" and Generating coverage files for Feedback Directed Optimization: AutoFDO ---------------------------------------------------------------------- +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 'perf inject' accepts the --itrace option in which case tracing data is removed and replaced with the synthesized events. e.g. |