Messages in this thread | | | Date | Thu, 18 Nov 2010 17:59:40 +0200 | From | Alexander Shishkin <> | Subject | Re: [PATCHv6 0/7] system time changes notification |
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On Wed, Nov 17, 2010 at 10:34:00PM +0100, Kay Sievers wrote: > On Wed, Nov 17, 2010 at 22:29, Alexander Shishkin <virtuoso@slind.org> wrote: > > On Wed, Nov 17, 2010 at 12:42:52PM -0800, Davide Libenzi wrote: > >> On Wed, 17 Nov 2010, Alexander Shishkin wrote: > >> > >> > > But what you folks really want for this stuff is an extension to > >> > > timerfd as you want to be able to poll, right? > >> > > > >> > > So what about the following: > >> > > > >> > > Add a new flag TDF_NOTIFY_CLOCK_WAS_SET to the timerfd flags. Now this > >> > > flag adds the timer to a separate list, which gets woken up when the > >> > > clock is set. > >> > > > >> > > No new syscall, just a few lines of code in fs/timerfd.c and > >> > > clock_was_set(). > >> > > > >> > > Thoughts ? > >> > > >> > Something like this (sans ugliness)? > >> > >> Oh, gosh, please. This is interface-multiplexing-a-palooza. > > > > Thomas made a suggestion, I came up with how it might look like so that > > pros and cons are clearer to everyone (or at least me) and can be discussed > > on technical grounds. Code talks, sort of. I'm not convinced that a timer > > that returns to userspace when the clock changes is such a bad idea, could > > you please elaborate? > > I like it. > > It's all bout timers, and timerfd is fine to use, I think. It has > nothing to do with "system-events", we ask for the timer to serve us, > but if the *time* changes underneath, we need to know to re-calculate. > > I think it's simple and fits very well in the current interface.
What would you say timerfd_gettime() should return for such a timer? Should it be current clock's time in it_value?
Regards, -- Alex -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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