On Mon, Apr 10, 2017 at 10:29:50AM -0700, Kenneth Graunke wrote: > On Monday, April 10, 2017 1:31:11 AM PDT Chris Wilson wrote: > > In general, does 10us resolution require compensation for clock_gettime() > > overhead and checking against clock_getres()? > > FWIW, I copied the 10us threshold from your brw-batch series. I'm happy > to adjust it.
I can honestly say there wasn't any thought behind it. :) I think it's about the right sort of threshold between "free" and "don't do this". A hundred "don't do this" really eats into your frame budget! > On my system, clock_getres(CLOCK_MONOTONIC[_RAW], &res) reports a > resolution of 1 nanosecond, so given a 10us = 10000ns threshold, I > doubt we need to consider it. Best to check on an atom - though I doubt any are as bad as Pineview (which was ~4ms iirc). MONOTONIC_RAW should be close to tsc resolution, so yes if we have RAW, we probably don't need to worry. Just do a check and warn if than the alarm threshold and see if anybody ever files a bug. -Chris -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
