[pulseaudio-discuss] [PATCH 00/12] A new ringbuffer based protocol for PulseAudio

David Henningsson david.henningsson at canonical.com
Mon Jun 23 23:56:38 PDT 2014

On 2014-06-17 16:10, Peter Meerwald wrote:
> Hello David,
>>>> Third iteration.
>>> paplay --latency-msec XXX audio_s16_2ch_44k1.wav
>>> on beagleboard-xm @ 1 GHz, kernel 3.15
> I want to re-benchmark with SHM off, at first sight it appears that load
> is LOWER (for low-latency)?!

Iochannel + no SHM could very well be faster than iochannel + SHM, 
because SHM means some extra code.

I would be surprised if iochannel + no SHM was significantly faster than 
srbchannel + SHM, because eventfds are supposed to be faster than pipes [1].

David Henningsson, Canonical Ltd.

[1] http://man7.org/linux/man-pages/man2/eventfd.2.html - "The kernel 
overhead of an eventfd file descriptor is much lower than that of a pipe".

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