Messages in this thread | | | Date | Mon, 27 Jan 2014 11:12:24 +0400 | From | Alexey Perevalov <> | Subject | Re: [PATCH v2 0/3] Deferrable timers support for timerfd API |
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Dear Thomas, could you please comment John's question (see bellow) regarding flags.
On 01/21/2014 11:12 PM, John Stultz wrote: > On 01/13/2014 02:43 AM, Alexey Perevalov wrote: >> Hello dear community. >> >> This is reworked patch set of original Anton's Vorontsov >> proposal regarding unified deferrable timers in the user space. >> http://lwn.net/Articles/514707/ >> >> >> I decided to resubmit it due we found it usefull for us too. >> >> timerfd was modified since Anton's commit, Alarm support was added. >> This isn't only rebase. Anton's previous version used deferrable timer >> in couple with hrtimer. This version uses only deferrable timer. It >> mean the behaviour of overrun number is different. >> e.g. if you don't poll one second timer for a 10 seconds - you'll get >> 10 overruns with hrtimer, but for deferrable timer it could be another value. >> > Sorry, last week was a little crazy and I didn't get a chance to closely > review this. But looking at this my major conceptual objection with the > previous patchset (introducing the new clockid) is gone. > > My remaining conceptual concern here is that the TIMER_DEFERRABLE flag > is a timerfd only construct here, and I worry we should make sure we > think this through well enough that the same functionality can be > supported via other timer interfaces (like clock_nanosleep, etc), which > may mean the functionality should be pushed more deeply into the hrtimer > subsystem. > > So main suggestion here is to make sure you cc Thomas Gleixner on future > iterations, so he can provide some thoughts on what the best approach > might be here. I know he also has some plans that might collide with the > jiffies_to_ktime work. > > Thomas: Any thought here? Should we be trying to unify the timerfd flags > and the posix timer flags (specifically things like TIMER_CANCEL_ON_SET, > which is currently timerfd-only)? Should a deferrable flag be added to > the hrtimer core or left to the timer wheel? > > thanks > -john >
-- Best regards, Alexey Perevalov
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