Re: [patch] boilerplate/gl: use glFlush instead of glFinish
Chris Wilson <[email protected]>
| Newsgroups | gmane.comp.lib.cairo |
|---|---|
| Message-ID | <[email protected]> |
On Thu, Aug 29, 2013 at 08:57:30PM +0000, Henry (Yu) Song - SISA wrote: > Hi, Chris > > There is no indication there are many frames (e.g, in cairo micro per test). I can either interpret the test as one drawing per frame, or many drawings per frame. In the former case, then after each loop, a glFlush () should be called, or the later case, a glFlush () should be called after all loops. > > Essentially, I found ,at least micro tests, do not model real performance accurately. The microbenchmarks are not intended to model application performance. They are meant to answer the question of "exactly how long does it take to do <n> operations?" That has to include the rendering pipeline for us to understand and model it accurately, hence glFinish. The other benchmarking example are the traces which span multiple rendering events and queue up many seconds of work by the time the trace finishes - which is not as real as one would like, but again the glFinish is required to make sure the rendering is complete before finishing the timer. The demos on the other handle, simply use the driver synchronisation through swapbuffers and measure fps. These are real applications, and do not require or use glFinish. -Chris -- Chris Wilson, Intel Open Source Technology Centre -- cairo mailing list [email protected] http://lists.cairographics.org/mailman/listinfo/cairo