diff options
| author | Sergei Trofimovich <[email protected]> | 2022-08-20 19:18:13 +0100 |
|---|---|---|
| committer | Andrew Morton <[email protected]> | 2022-09-11 21:55:07 -0700 |
| commit | aa06a9bd853306c239f759018fb227d7e8f4e203 (patch) | |
| tree | 1fe5f4e788106cf7a1b71adbd210d6cb9159ac12 /tools/perf/scripts/python/bin | |
| parent | cba7543e1515e79a85d37df85a0eb2cf0f07d115 (diff) | |
ia64: fix clock_getres(CLOCK_MONOTONIC) to report ITC frequency
clock_gettime(CLOCK_MONOTONIC, &tp) is very precise on ia64 as it uses ITC
(similar to rdtsc on x86). It's not quite a hrtimer as it is a few times
slower than 1ns. Usually 2-3ns.
clock_getres(CLOCK_MONOTONIC, &res) never reflected that fact and reported
0.04s precision (1/HZ value).
In https://bugs.gentoo.org/596382 gstreamer's test suite failed loudly
when it noticed precision discrepancy.
Before the change:
clock_getres(CLOCK_MONOTONIC, &res) reported 250Hz precision.
After the change:
clock_getres(CLOCK_MONOTONIC, &res) reports ITC (400Mhz) precision.
The patch is based on matoro's fix. I added a bit of explanation why we
need to special-case arch-specific clock_getres().
[[email protected]: coding-style cleanups]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Sergei Trofimovich <[email protected]>
Cc: matoro <[email protected]>
Cc: Émeric Maschino <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Diffstat (limited to 'tools/perf/scripts/python/bin')
0 files changed, 0 insertions, 0 deletions