cvs commit: src/sys/kern subr_power.c
jhb at freebsd.org
Wed Nov 9 16:35:18 GMT 2005
On Wednesday 09 November 2005 11:25 am, M. Warner Losh wrote:
> In message: <200511091001.45475.jhb at freebsd.org>
> John Baldwin <jhb at freebsd.org> writes:
> : On Wednesday 09 November 2005 08:56 am, Scott Long wrote:
> : > Bruce Evans wrote:
> : > > On Wed, 9 Nov 2005, Warner Losh wrote:
> : > >> Modified files:
> : > >> sys/kern subr_power.c
> : > >> Log:
> : > >> Kick off the suspend sequence from the keyboard in a SWI rather
> : > >> than in the hardware interrupt context (even if it is likely just an
> : > >> ithread). We don't document that suspend/resume routines are run
> : > >> from such a context and some of the things that happen in those
> : > >> routines aren't interrupt safe. Since there's no real need to run
> : > >> from that context, this restores assumptions that suspend routines
> : > >> have made.
> : > >>
> : > >> This fixes Thierry Herbelot's 'Trying to sleep while sleeping is
> : > >> prohibited' problem.
> : > >
> : > > Er, SWIs are interrupts too. Trying to sleep in a SWI handler should
> : > > cause the same message. This commit uses the general taskqueue SWI
> : > > handler. taskqueue(9) implicitly says that only the taskqueue thread
> : > > handler can sleep (it gives malloc(M_WAITOK) as an example of
> : > > something that can only be done in thread context).
> : > >
> : > > Bruce
> : >
> : > You're right, but sleeping in SWI's has never been enforced. CAM
> : > relies on it, for better or worse, and until that's fixed it's
> : > pointless to start enforcing it.
> : Well, I don't think we should knowingly go around adding more instances
> : of it. :) In this case it is really easy to just use taskqueue_thread
> : rather than taskqueue_swi.
> SWI, thread, what's the difference? [*] In this case, nothing bad will
> happen if we do this in a thread and bad things might happen in the
> future if we don't. Sounds like a no-brainer: I changed it to
> [*] That's actually a good question to have answered in the taskqueue
> man page... I use it as a rhetorical question here...
I've thought about killing taskqueue_swi in favor of taskqueue_thread
John Baldwin <jhb at FreeBSD.org> <>< http://www.FreeBSD.org/~jhb/
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