On Mon, 15 Aug 2022 06:49:44 +0100 Sergei Trofimovich <slyich@xxxxxxxxx> wrote: > 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. It adds a bit of explanation why we > need to special-case arch-specific clock_getres(). > It would be best (and nice) to include the original developer's Signed-off-by: and to Cc Émeric Maschino if possible? Could you please take care of these paperwork issues?
|