Re: [rfc][patch] API for timer hooks

john stultz
2005-08-15T17:19:18Z

On Sat, 2005-08-13 at 17:36 +0400, Stas Sergeev wrote:
> Hello.
>
> Right now it seems like the only interface
> for registering the timer hooks is that one
> of kernel/profile.c, and it is very limited.
> The arch-specific timer hooks are provided
> in an arch-specific headers as a static
> functions.
> Since my driver needs the timer hook, I
> thought it might be a good idea to add an
> API for registering the timer hooks.
> The attached patch adds such an API and
> converts all the relevant places to use it.
> I changed oprofile to use it, and also
> converted the arch-specific hooks, which
> looks like a fair cleanup.
>
> The API allows to register, unregister
> and grab the timer hook. The grabbing
> hook will always be executed first, and
> can decide to prevent an execution of
> the rest ones. The hook can have the
> "run_always" flag set, in which case it
> won't be bypassed, regardless of the
> grabbing hook.
>
> Does such an API look viable?
> As usual, it is needed for the PC-Speaker
> PCM driver that is currently in an ALSA CVS,
> awaiting for the proper interface to appear
> in the kernel.

Interesting. Could you explain why the soft-timer interface doesn't
suffice?

thanks
-john