[PATCH v3 0/6] Perf tool: Support TSC for Arm64

From: Leo Yan
Date: Wed Sep 02 2020 - 09:41:27 EST


This patch set is to refactor the changes for the old patch set 'Perf
tool: Enable Arm arch timer counter and arm-spe's timestamp' [1].

After reviewed the old patch sets (thanks Wei Li and Al Grant), we
think it's right way to consolidate TSC code and extend the TSC
implementation to common code which can support both x86 and Arm64;
so far, for x86 it needs to support cap_user_time_zero and for Arm64
it needs to support cap_user_time_short. For architecture specific
code, every arch only needs to implement its own rdtsc() to read out
timer's counter.

This patch set is to refactor TSC implementation and move TSC code from
x86 folder to util/tsc.c, this allows all archs to reuse the code. And
alse move the TSC testing from x86 folder to tests so can work as a
common testing.

This patch set has been tested on Arm64 (DB410c) and x86_64. Both can
pass the testing:

$ perf test list
[...]
68: Convert perf time to TSC
[...]

$ perf test 68 -v
68: Convert perf time to TSC
--- start ---
test child forked, pid 10961
mmap size 528384B
1st event perf time 35715036563417 tsc 686221770989
rdtsc time 35715036649719 tsc 686221772647
2nd event perf time 35715036660448 tsc 686221772852
test child finished with 0
---- end ----
Convert perf time to TSC: Ok

Changes from v2:
* Refactored patch set to move TSC common code to util/tsc.c (Wei/Al);
* Moved TSC testing to perf/tests (Wei);
* Dropped Arm SPE timestamp patch so can have clear purpose and easier
reviewing; will send Arm SPE timestamp as separate patch.

[1] https://lore.kernel.org/patchwork/cover/1285130/

Leo Yan (6):
perf tsc: Move out common functions from x86
perf tsc: Add rdtsc() for Arm64
perf tsc: Calculate timestamp with cap_user_time_short
perf tsc: Support cap_user_time_short for event TIME_CONV
perf tests tsc: Make tsc testing as a common testing
perf tests tsc: Add checking helper is_supported()

tools/lib/perf/include/perf/event.h | 4 +
tools/perf/arch/arm64/util/Build | 1 +
tools/perf/arch/arm64/util/tsc.c | 14 ++++
tools/perf/arch/x86/include/arch-tests.h | 1 -
tools/perf/arch/x86/tests/Build | 1 -
tools/perf/arch/x86/tests/arch-tests.c | 4 -
tools/perf/arch/x86/util/tsc.c | 73 +----------------
tools/perf/tests/Build | 1 +
tools/perf/tests/builtin-test.c | 5 ++
.../{arch/x86 => }/tests/perf-time-to-tsc.c | 13 +++
tools/perf/tests/tests.h | 2 +
tools/perf/util/jitdump.c | 14 ++--
tools/perf/util/synthetic-events.c | 8 --
tools/perf/util/tsc.c | 81 +++++++++++++++++++
tools/perf/util/tsc.h | 5 ++
15 files changed, 136 insertions(+), 91 deletions(-)
create mode 100644 tools/perf/arch/arm64/util/tsc.c
rename tools/perf/{arch/x86 => }/tests/perf-time-to-tsc.c (93%)

--
2.17.1