Messages in this thread | | | Date | Fri, 12 Jun 2015 10:58:42 -0700 | Subject | Re: [PATCH 0/5 v2] Fixes for leapsecond expiring early ABS_TIME CLOCK_REALTIME timers | From | John Stultz <> |
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On Fri, Jun 12, 2015 at 7:52 AM, Dave Jones <davej@codemonkey.org.uk> wrote: > On Thu, Jun 11, 2015 at 03:54:52PM -0700, John Stultz wrote: > > So this is a second round at trying to address the issue, trying > > to integrate feedback from Ingo and Thomas, trying to simplify > > what I can. I've also split out the changes so each can be > > more easily reviewed. Its still not tiny, but its simpler. > > > > This series is against tip/timers/core, and the first patch isn't > > strictly related but is a fix that is needed in tip/timers/core. > > > > As Prarit reported here: > > https://lkml.org/lkml/2015/5/27/458 > > > > Since the leapsecond is applied at timer tick time, and not > > the actual second edge, ABS_TIME CLOCK_REALTIME timers set for > > right after the leapsecond could fire a second early, since > > some timers may be expired before we trigger the timekeeping > > timer, which then applies the leapsecond. > > > > Thus this patch series tries to address this issue, including > > extending the leap-a-day test to catch this problem, as well > > as other relevant fixups I found while working on the code. > > > > This series has only had limited testing, so I wanted to send > > it out for initial review and comment. Folks can grab this tree > > via git for testing here: > > https://git.linaro.org/people/john.stultz/linux.git dev/early-leap-timer > > Any idea how far back this reaches ? Ie, which longterm stable releases > might be affected by this ?
I suspect all the way back to where hrtimers were introduced and possibly further.
> (It really creeps me out that we're still changing this code so close > to the next leap second event).
Yea. This isn't something I'm suggesting folks deploy for the end of this month. It likely will be 4.3 material.
thanks -john
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