* John Stultz <john.stu...@linaro.org> wrote: > On Sat, May 27, 2017 at 12:38 AM, Ingo Molnar <mi...@kernel.org> wrote: > > > > * John Stultz <john.stu...@linaro.org> wrote: > > > >> As part of the Linaro Linux Kernel Functional Test (LKFT) > >> effort, test failures from kselftest/timer's > >> inconsistency-check were reported connected to > >> CLOCK_MONOTONIC_RAW, on the HiKey platform. > >> > >> Digging in I found that an old issue with how sub-ns accounting > >> is handled with the RAW time which was fixed long ago with the > >> CLOCK_MONOTONIC/REALTIME ids, but missed with RAW time, was > >> present. > >> > >> Additionally, running further tests, I uncovered an issue with > >> how the clocksource read function is handled when clocksources > >> are changed, which can cause crashes. > >> > >> Both of these issues have not been uncovered in x86 based > >> testing due to x86 not using vDSO to accelerate > >> CLOCK_MONOTONIC_RAW, combined with the HiKey's arch_timer > >> clocksource being fast to access but incrementing slowly enough > >> to get multiple reads using the same counter value (which helps > >> uncover time handing issues), along with the fact that none of > >> the x86 clocksources making use of the clocksource argument > >> passed to the read function. > >> > >> This patchset addresses these two issues. > > > > AFAICS only the first two patches are fixes, the other two patches are > > cleanups/simplifications that resulted out of the debugging effort, right? > > Actually the first three are fixes (ARM64 still sees discontinuities > until the vDSO is fixed), the last one is a cleanup.
Ok, please make it more apparent in the changelog of the third patch what user observable mis-behavior is actually fixed by it: corrupted time, non-monotonic time, or something else? Thanks, Ingo