| 19c3e4db | 22-Jul-2024 |
James Clark <[email protected]> |
perf: cs-etm: Create decoders based on the trace ID mappings
Now that each queue has a unique set of trace ID mappings, use this
list to create the decoders. In unformatted mode just add a single
ma
perf: cs-etm: Create decoders based on the trace ID mappings
Now that each queue has a unique set of trace ID mappings, use this
list to create the decoders. In unformatted mode just add a single
mapping so only one decoder is made.
Previously each queue would have a decoder created for each traced CPU
on the system but this won't work anymore because CPUs can have
overlapping trace IDs.
This also means that the CORESIGHT_TRACE_ID_UNUSED_FLAG isn't needed
any more. If mappings aren't added then decoders aren't created, rather
than needing a flag to suppress creation.
Reviewed-by: Mike Leach <[email protected]>
Signed-off-by: James Clark <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Alexandre Torgue <[email protected]>
Cc: Anshuman Khandual <[email protected]>
Cc: Ganapatrao Kulkarni <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: John Garry <[email protected]>
Cc: Kan Liang <[email protected]>
Cc: Leo Yan <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Maxime Coquelin <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Suzuki Poulouse <[email protected]>
Cc: Will Deacon <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: James Clark <[email protected]>
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
show more ...
|
| 5670ebf5 | 20-Jan-2023 |
James Clark <[email protected]> |
perf cs-etm: Ensure that Coresight timestamps don't go backwards
There are some edge cases around estimated timestamps that can result
in them going backwards.
One is that after a discontinuity, th
perf cs-etm: Ensure that Coresight timestamps don't go backwards
There are some edge cases around estimated timestamps that can result
in them going backwards.
One is that after a discontinuity, the last used timestamp is set to 0.
The duration of the next range is then subtracted which could result in
an earlier timestamp than the last instruction. Fix this by not
resetting the last timestamp used on a discontinuity, and make sure that
new estimated timestamps are clamped to be later than that.
Another case is that estimated timestamps could compound over time to
end up being more than the next real timestamp in the trace. Fix this by
clamping the estimates in cs_etm_decoder__do_soft_timestamp() to be no
later than it.
cs_etm_decoder__do_soft_timestamp() also updated next_cs_timestamp,
which meant that the next real timestamp was lost and not stored
anywhere. Fix that by only updating cs_timestamp for estimates and keep
next_cs_timestamp untouched.
Finally, use next_cs_timestamp to signify if a timestamp has been
received previously. Because cs_timestamp has the first range
subtracted, it could technically go to 0 which would break the logic.
Testing
=======
It can be verified that timestamps don't go backwards when tracing on a
single core with the following commands. Across multiple cores it's
expected that timestamps are interleaved:
$ perf record -e cs_etm/@tmc_etr0/k -C 4 taskset -c 4 sleep 1
$ perf script --itrace=i1ns --ns -Fcomm,tid,pid,time,cpu,event,ip,sym,addr,symoff,flags,callindent > itrace
$ sed 's/://g' itrace | awk -F ' ' ' { print $4 } ' | awk '{ if ($1 < prev) { print "line:" NR " " $0 } {prev=$1}}'
Reported-by: Tanmay Jagdale <[email protected]>
Signed-off-by: James Clark <[email protected]>
Acked-by: Suzuki Poulouse <[email protected]>
Tested-by: Tanmay Jagdale <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Bharat Bhushan <[email protected]>
Cc: George Cherian <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: John Garry <[email protected]>
Cc: Leo Yan <[email protected]>
Cc: Linu Cherian <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Mathieu Poirier <[email protected]>
Cc: Mike Leach <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Sunil Kovvuri Goutham <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: [email protected]
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
show more ...
|
| f4aef1ea | 06-Aug-2021 |
James Clark <[email protected]> |
perf cs-etm: Initialise architecture based on TRCIDR1
Currently the architecture is hard coded as ARCH_V8, but from ETMv4.4
onwards this should be ARCH_AA64.
Reviewed-by: Leo Yan <[email protected]
perf cs-etm: Initialise architecture based on TRCIDR1
Currently the architecture is hard coded as ARCH_V8, but from ETMv4.4
onwards this should be ARCH_AA64.
Reviewed-by: Leo Yan <[email protected]>
Signed-off-by: James Clark <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: John Garry <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Mathieu Poirier <[email protected]>
Cc: Mike Leach <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Suzuki Poulouse <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: [email protected]
Cc: [email protected]
Link: https //lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
show more ...
|
| 9182f04a | 21-Jul-2021 |
James Clark <[email protected]> |
perf cs-etm: Pass unformatted flag to decoder
The TRBE (Trace Buffer Extension) feature allows a separate trace buffer
for each trace source, therefore the trace wouldn't need to be
formatted. The d
perf cs-etm: Pass unformatted flag to decoder
The TRBE (Trace Buffer Extension) feature allows a separate trace buffer
for each trace source, therefore the trace wouldn't need to be
formatted. The driver was introduced in commit 3fbf7f011f24
("coresight: sink: Add TRBE driver").
The formatted/unformatted mode is encoded in one of the flags of the
AUX record. The first AUX record encountered for each event is used to
determine the mode, and this will persist for the remaining trace that
is either decoded or dumped.
Reviewed-by: Mathieu Poirier <[email protected]>
Signed-off-by: James Clark <[email protected]>
Cc: Al Grant <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Anshuman Khandual <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: John Garry <[email protected]>
Cc: Leo Yan <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Mike Leach <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Suzuki Poulouse <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: [email protected]
Cc: [email protected]
Link: https //lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
show more ...
|
| c1a6165a | 17-May-2021 |
James Clark <[email protected]> |
perf cs-etm: Prevent and warn on underflows during timestamp calculation.
When a zero timestamp is encountered, warn once. This is to make
hardware or configuration issues visible. Also suggest that
perf cs-etm: Prevent and warn on underflows during timestamp calculation.
When a zero timestamp is encountered, warn once. This is to make
hardware or configuration issues visible. Also suggest that the issue
can be worked around with the --itrace=Z option.
When an underflow with a non-zero timestamp occurs, warn every time.
This is an unexpected scenario, and with increasing timestamps, it's
unlikely that it would occur more than once, therefore it should be
ok to warn every time.
Only try to calculate the timestamp by subtracting the instruction
count if neither of the above cases are true. This makes attempting
to decode files with zero timestamps in non-timeless mode
more consistent. Currently it can half work if the timestamp wraps
around and becomes non-zero, although the behavior is undefined and
unpredictable.
Signed-off-by: James Clark <[email protected]>
Reviewed-by: Leo Yan <[email protected]>
Cc: Al Grant <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Anshuman Khandual <[email protected]>
Cc: Branislav Rankov <[email protected]>
Cc: Denis Nikitin <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: John Garry <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Mathieu Poirier <[email protected]>
Cc: Mike Leach <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Suzuki Poulouse <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: [email protected]
Cc: [email protected]
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
show more ...
|