From mboxrd@z Thu Jan 1 00:00:00 1970 From: michi1@michaelblizek.twilightparadox.com (Michael Blizek) Date: Mon, 16 May 2011 06:42:20 +0200 Subject: is the tickless kernel now the "standard"? In-Reply-To: <20110515180112.GA21222@kroah.com> References: <20110515165623.GA6629@kroah.com> <20110515180112.GA21222@kroah.com> Message-ID: <20110516044220.GA2043@michaelblizek.twilightparadox.com> To: kernelnewbies@lists.kernelnewbies.org List-Id: kernelnewbies.lists.kernelnewbies.org Hi! On 11:01 Sun 15 May , Greg KH wrote: > On Sun, May 15, 2011 at 01:48:43PM -0400, Robert P. J. Day wrote: ... > > ok, good to know. i assume, then, that it's fairly pointless to use > > the value of "jiffies" for anything that requires even moderate > > accuracy. i was poking around the timer code, and i can see this in > > kernel/time/timekeeping.c: > > No, never access jiffies directly, use the correct delay and timer > functions instead, they will handle things properly. And that's the way > to get correct accuracy if you need it. When switchint from jiffies+timers to hrtimers what should be used as a monotonic time source? ktime_get()? What am I supposed to do if timekeeping_valid_for_hres() returns 0? Can I ignore this? What does it mean this highres timer are not available during system startup? Are they running with lower resolution or not at all? -Michi