From: Rusty Russell <rusty@rustcorp.com.au>
To: Matthew Wilcox <matthew@wil.cx>
Cc: Michal Schmidt <mschmidt@redhat.com>,
Daniel Walker <dwalker@mvista.com>,
linville@tuxdriver.com, mingo@elte.hu,
linux-kernel@vger.kernel.org, linux-wireless@vger.kernel.org,
arjan@infradead.org
Subject: Re: [PATCH] net: wireless: airo semaphore to mutex
Date: Tue, 27 May 2008 14:37:22 +1000 [thread overview]
Message-ID: <200805271437.23114.rusty@rustcorp.com.au> (raw)
In-Reply-To: <20080527021503.GH30894@parisc-linux.org>
On Tuesday 27 May 2008 12:15:03 Matthew Wilcox wrote:
> On Tue, May 27, 2008 at 11:17:22AM +1000, Rusty Russell wrote:
> > On Tuesday 27 May 2008 03:29:14 Michal Schmidt wrote:
> > > Mutexes are not allowed in interrupt context, not even mutex_trylock.
> >
> > As an aside, does anyone know why? I know the documentation says so, but
> > it wasn't immediately obvious to me. I asked before to no response...
>
> Because mutexes have an owner. In interrupt context, there is no owner.
> This owner is used to do priority boosts as well as debugging.
Shows how little I know, I didn't see priority boosting in my glance thru
mutex.c.
But it seems like mutex_trylock_irq would be easy to add if needed, if only
for clarity.
Thanks!
Rusty.
next prev parent reply other threads:[~2008-05-27 4:37 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-05-22 23:21 [PATCH] net: wireless: airo semaphore to mutex Daniel Walker
2008-05-26 17:29 ` Michal Schmidt
2008-05-26 17:59 ` Daniel Walker
2008-05-27 1:17 ` Rusty Russell
2008-05-27 2:15 ` Matthew Wilcox
2008-05-27 4:34 ` Daniel Walker
2008-05-27 11:24 ` Matthew Wilcox
2008-05-27 4:37 ` Rusty Russell [this message]
2008-05-27 13:13 ` Matthew Wilcox
2008-05-27 13:48 ` Dan Williams
2008-05-27 15:08 ` Daniel Walker
2008-05-27 15:34 ` Matthew Wilcox
2008-05-27 16:01 ` Daniel Walker
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