[PATCH v2 0/7] perf arm-spe: Enable timestamp

Leo Yan leo.yan at linaro.org
Sat Apr 3 08:23:39 BST 2021


As we know, the timestamp is important for AUX trace; it's mainly used
to correlate between perf events and AUX trace, allows to generate
events with time ordered manner.  There have several good examples of
enabling timestamp for AUX trace (like Intel-pt, Intel-bts, etc).

Since the conversion between TSC and kernel timestamp has been supported
on Arm64, TSC is a naming convention from x86, but perf now has reused
it to support Arm arch timer counter.

This patch set is to enable timestamp for Arm SPE trace.  It reads out
TSC parameters from mmap page and stores into auxtrace info structure;
the TSC parameters are used for conversion between timer counter and
kernel time and which is applied for Arm SPE samples.

This patch set can be clearly applied on perf/core branch with:

  commit 6859bc0e78c6 ("perf stat: Improve readability of shadow stats")

Ths patch series has been tested on Hisilicon D06 platform.

After:

  # perf script -F comm,time,cpu,pid,dso,ip,sym

              perf  2408 [032]   168.680297:  ffffbd1253690a3c perf_event_exec ([kernel.kallsyms])
              perf  2408 [032]   168.680297:  ffffbd1253690a3c perf_event_exec ([kernel.kallsyms])
   false_sharing.e  2408 [032]   168.680317:  ffffbd1253683f50 perf_iterate_ctx.constprop.0 ([kernel.kallsyms])
   false_sharing.e  2408 [032]   168.680317:  ffffbd1253683f50 perf_iterate_ctx.constprop.0 ([kernel.kallsyms])
   false_sharing.e  2408 [032]   168.680319:  ffffbd1253683f70 perf_iterate_ctx.constprop.0 ([kernel.kallsyms])
   false_sharing.e  2408 [032]   168.680319:  ffffbd1253683f70 perf_iterate_ctx.constprop.0 ([kernel.kallsyms])
   false_sharing.e  2408 [032]   168.680367:  ffffbd12539b03ec __arch_clear_user ([kernel.kallsyms])
   false_sharing.e  2408 [032]   168.680375:  ffffbd1253721440 kmem_cache_alloc ([kernel.kallsyms])
   false_sharing.e  2408 [032]   168.680375:  ffffbd1253721440 kmem_cache_alloc ([kernel.kallsyms])
   false_sharing.e  2408 [032]   168.680375:  ffffbd1253721440 kmem_cache_alloc ([kernel.kallsyms])
   false_sharing.e  2408 [032]   168.680375:  ffffbd1253721440 kmem_cache_alloc ([kernel.kallsyms])
   false_sharing.e  2408 [032]   168.680376:  ffffbd1253683f70 perf_iterate_ctx.constprop.0 ([kernel.kallsyms])
   false_sharing.e  2408 [032]   168.680376:  ffffbd1253683f70 perf_iterate_ctx.constprop.0 ([kernel.kallsyms])
   false_sharing.e  2408 [032]   168.680376:  ffffbd1253683f70 perf_iterate_ctx.constprop.0 ([kernel.kallsyms])

Changes from v1:
* Rebased patch series on the latest perf/core branch;
* Fixed the patch for dumping TSC parameters to support both the
  older and new auxtrace info format.


Leo Yan (7):
  perf arm-spe: Remove unused enum value ARM_SPE_PER_CPU_MMAPS
  perf arm-spe: Store TSC parameters in auxtrace info
  perf arm-spe: Dump TSC parameters
  perf arm-spe: Convert event kernel time to counter value
  perf arm-spe: Assign kernel time to synthesized event
  perf arm-spe: Bail out if the trace is later than perf event
  perf arm-spe: Don't wait for PERF_RECORD_EXIT event

 tools/perf/arch/arm64/util/arm-spe.c | 23 +++++++
 tools/perf/util/arm-spe.c            | 89 +++++++++++++++++++++++-----
 tools/perf/util/arm-spe.h            |  7 ++-
 3 files changed, 103 insertions(+), 16 deletions(-)

-- 
2.25.1




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