> -----Original Message-----
> From: Leo Yan <[email protected]>
> Sent: 03 April 2021 08:24
> To: Arnaldo Carvalho de Melo <[email protected]>; John Garry
> <[email protected]>; Will Deacon <[email protected]>; Mathieu Poirier
> <[email protected]>; James Clark <[email protected]>; Al Grant
> <[email protected]>; Peter Zijlstra <[email protected]>; Ingo Molnar
> <[email protected]>; Mark Rutland <[email protected]>; Alexander
> Shishkin <[email protected]>; Jiri Olsa <[email protected]>;
> Namhyung Kim <[email protected]>; Adrian Hunter
> <[email protected]>; [email protected]; linux-
> [email protected]
> Cc: [email protected]
> Subject: [PATCH v2 0/7] perf arm-spe: Enable timestamp
>
> 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;
Why not synthesize a PERF_RECORD_TIME_CONV - isn't that specifically to
capture the TSC parameters from the mmap page? If a generic mechanism
exists it would be better to use it, otherwise we'll have to do this again for
future trace formats.
perf_read_tsc_conversion and perf_event__synth_time_conv are currently
in arch/x86/util/tsc.c, but nothing in them is x86-specific and they could be
moved somewhere more generic.
Al
> 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
