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doc: fix typos in trace.rst
Fix obvious typos. Use US spelling consistently. Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
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@ -4,7 +4,7 @@
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Tracing in U-Boot
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=================
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U-Boot supports a simple tracing feature which allows a record of excecution
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U-Boot supports a simple tracing feature which allows a record of execution
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to be collected and sent to a host machine for analysis. At present the
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main use for this is to profile boot time.
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@ -161,10 +161,10 @@ limit of the trace buffer size you have specified. Once that is exhausted
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no more data will be collected.
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Collecting trace data has an affect on execution time/performance. You
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will notice this particularly with trvial functions - the overhead of
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will notice this particularly with trivial functions - the overhead of
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recording their execution may even exceed their normal execution time.
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In practice this doesn't matter much so long as you are aware of the
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effect. Once you have done your optimisations, turn off tracing before
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effect. Once you have done your optimizations, turn off tracing before
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doing end-to-end timing.
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The best time to start tracing is right at the beginning of U-Boot. The
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@ -184,7 +184,7 @@ the OS. In practical terms, U-Boot runs the 'fakegocmd' environment
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variable at this point. This variable should have a short script which
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collects the trace data and writes it somewhere.
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Trace data collection relies on a microsecond timer, accesed through
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Trace data collection relies on a microsecond timer, accessed through
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timer_get_us(). So the first think you should do is make sure that
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this produces sensible results for your board. Suitable sources for
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this timer include high resolution timers, PWMs or profile timers if
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@ -285,7 +285,7 @@ Options
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Specify U-Boot map file
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-p <trace_file>
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Specifiy profile/trace file
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Specify profile/trace file
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Commands:
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@ -315,11 +315,11 @@ time:
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2. Build U-Boot with tracing and run it. Note the difference in boot time
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(it is common for tracing to add 10% to the time)
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3. Collect the trace information as descibed above. Use this to find where
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3. Collect the trace information as described above. Use this to find where
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all the time is being spent.
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4. Take a look at that code and see if you can optimise it. Perhaps it is
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possible to speed up the initialisation of a device, or remove an unused
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4. Take a look at that code and see if you can optimize it. Perhaps it is
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possible to speed up the initialization of a device, or remove an unused
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feature.
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5. Rebuild, run and collect again. Compare your results.
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