On Sun, Apr 29, 2012 at 10:40:48PM +1200, Michael Kerrisk (man-pages) wrote: > On Sun, Apr 29, 2012 at 10:21 AM, Simon Paillard <spaill...@debian.org> wrote: > > tags + upstream > > thanks > > > > Hi, > > > > On Mon, Aug 10, 2009 at 11:30:34AM -0700, Josh Triplett wrote: > >> Package: manpages > >> Version: 3.22-1 > >> Severity: wishlist > >> > >> Developers of real-time programs (programs using real-time scheduling > >> and/or expecting low latency) sometimes see CLOCK_REALTIME and think > >> they want to use that, when they almost certainly don't. Please > >> consider adding some clarification that the "real-time" of > >> CLOCK_REALTIME refers to wall-clock time (as opposed to CPU or process > >> time, for instance) and that developers of real-time applications want > >> to use CLOCK_MONOTONIC. > > > > Michael Kerrisk improved clock_getres.2 in manpages 3.40: > > > > .B CLOCK_MONOTONIC > > Clock that cannot be set and represents monotonic time since > > some unspecified starting point. > > +This clock is not affected by discontinuous jumps in the system time > > +(e.g., if the system administrator manually changes the clock), > > +but is affected by the incremental adjustments performed by > > +.BR adjtime (2) > > +and NTP. > > > > Maybe one can add (please proofread my english): > > "This clock allow to precisely measuring time elapsed, for use in real-time > > programs." > > > > http://pubs.opengroup.org/onlinepubs/009604599/functions/clock_getres.html > > Simon, would that text not better apply to CLOCK_MONOTONIC_RAW?
Probably, yes. Ideally, I'd also like to see something like this added to the description of CLOCK_REALTIME, to help avert a common trap people fall into: 'The "realtime" in the name CLOCK_REALTIME refers to wall-clock time, not to suitability for realtime (latency-sensitive) applications. Such applications generally want to use CLOCK_MONOTONIC or CLOCK_MONOTONIC_RAW.' - Josh Triplett -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
