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Re: kthread with kpause or callout

On Mon, 8 Feb 2010 15:09:55 +0100
Martin Husemann <> wrote:

> On Mon, Feb 08, 2010 at 03:04:07PM +0100, Frank Wille wrote:
> > [...] May I acquire this mutex during a callout (which is a
> > softint, as I understand)? Will the softint sleep or busy-wait?
> Depends on the mutex type, from mutex(9):
> [...]
>                  Adaptive mutexes cannot be acquired from a hardware
> interrupt handler.
> [...]
> The wording is not explicit, but a softint is not allowed to block on
> an adaptive mutex,

Yes, this is what I thought as well, but the man page only mentions
hardware interrupts. Are you sure about it?

Hmmm... from softint(9):
     [...] Unlike hardware interrupts,
     software interrupts do have thread context.  They may block on synchro-
     nization objects, sleep, and resume execution at a later time.

IMHO that would allow my callout to sleep on acquiring the mutex?

Frank Wille

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