[pulseaudio-discuss] Patch review status wiki page updated

[Alexander E. Patrakov]

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