Re: Interrupt handlers and mutex

[Antti Kantee <pooka%cs.hut.fi@localhost>]

On Tue Jan 05 2010 at 17:13:27 +0100, Manuel Bouyer wrote:
> Is there some documentation on how "fast" software interrupts works ?
> what happens to the borrowed thread when the soft interrupt handler
> wants to sleep ?

It's documented in fairly extensive comments in kern_softint.c.
If a softint blocks, the borrowed thread is free to run (barring
other interrupt activities) and softint processing continues later in
the softint lwp.  Actually, it's pretty close to how libpuffs handles
context switches.  I should've called the scheme "fast" instead of "lazy"
in libpuffs for the proper marketing spin ;)