[alsa-devel] snd_pcm_writei VS snd_pcm_mmap_writei

Jaroslav Kysela perex at perex.cz
Fri Nov 19 08:09:29 CET 2010

On Fri, 19 Nov 2010, Irfan Shaikh wrote:

> Hello,
>         Please tell me
>         a) Difference between working of snd_pcm_mmap_writei and snd_pcm_writei ?
>         b) Performance wise which is better ?

The mmap functions does not require user space / kernel context switches.

>         When i use gettimeofday almost profile time comes almost same for both of them.

With current hw power, there are no major differences.


Jaroslav Kysela <perex at perex.cz>
Linux Kernel Sound Maintainer
ALSA Project, Red Hat, Inc.

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