On Wed, 17 Aug 2022 12:21:03 -0700 Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > 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? Sounds good! I'll use matoro's nickname as is for S-o-B the way matoro is comfortable with to share it. Will add Émeric in v2 and send out in a few minutes. -- Sergei
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