22.09.2014 05:20, David Henningsson wrote: > On 2014-09-21 12:28, Alexander E. Patrakov wrote: >> 21.09.2014 16:19, Tanu Kaskinen wrote: >>> Patch review status updated: >>> http://www.freedesktop.org/wiki/Software/PulseAudio/PatchStatus/ >> >> "Reduce hardware pointer update syscalls" is not exactly "waiting for >> review". I have tested it and found it to fail an assertion when the >> sink is autosuspended. Also I did some profiling using perf, but testing >> on one card does not give enough justification to reject the patch on >> the "no performance improvement" basis. It does look like a valid >> cleanup and simplification attempt, though. >> >> Of course this cannot count as a proper review, but, due to the failed >> assertion, the need for a new version of the patch is quite obvious at >> this point. > > I'm currently waiting for Peter to see if he notices any substantial > perfomance improvements on his card(s). If he does, it makes sense to > submit a new, and more robust, version. If not, maybe it's easier to > just drop the idea (no use optimising things that don't take much time > anyway). I think it may still be a valid optimization, but only when combined with the removal of the loop that increases j from mmap_write() and unix_write(). I.e., currently, there may be several attempts to write data, i.e. several syscalls that move the pointer (via writei or mmap_commit). In the worst case, by asking Peter to test the version that still has the loop about j, you are wasting his time. -- Alexander E. Patrakov
