From: Robert Love <rml@tech9.net>
To: Manfred Spraul <manfred@colorfullife.com>
Cc: Pavel Machek <pavel@suse.cz>,
Roger Larsson <roger.larsson@norran.net>,
linux-kernel@vger.kernel.org, nigel@nrg.org
Subject: Re: [SMP lock BUG?] Re: Feedback on preemptible kernel patch
Date: 17 Sep 2001 20:19:28 -0400 [thread overview]
Message-ID: <1000772375.12771.8.camel@phantasy> (raw)
In-Reply-To: <003b01c13fc9$d04a4830$010411ac@local>
In-Reply-To: <000901c138bbe151270/mnt/sendme10411ac@local> <1000007070.836.14.camel@phantasy> <001a01c1390262c7f30/mnt/sendme10411ac@local> <20010914091558.A35@toy.ucw.cz> <003b01c13fc9$d04a4830$010411ac@local>
On Mon, 2001-09-17 at 18:40, Manfred Spraul wrote:
> > is it legal to kmap_atomic(a,b); kmap_atomic(c,d); kunmap_atomic(a,b);
>
> Yes, that's legal - just think about one kmap_atomic from process
> context, and another one in irq context.
>
> > If so, your patch may need some ounting....
> > Pavel
>
> I hope ctx_sw_off does internal counting, correct?
yes, ctx_sw_off atomically increments a counter and ctx_sw_on
atomic_dec_and_test()s it.
--
Robert M. Love
rml at ufl.edu
rml at tech9.net
next prev parent reply other threads:[~2001-09-18 0:18 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-09-08 23:11 [SMP lock BUG?] Re: Feedback on preemptible kernel patch Manfred Spraul
2001-09-09 3:44 ` Robert Love
2001-09-09 7:38 ` Manfred Spraul
[not found] ` <001a01c1390262c7f30/mnt/sendme10411ac@local>
2001-09-14 9:15 ` Pavel Machek
2001-09-17 22:40 ` Manfred Spraul
2001-09-18 0:19 ` Robert Love [this message]
2001-09-17 22:41 ` Robert Love
-- strict thread matches above, loose matches on Subject: below --
2001-09-08 17:33 Arjan Filius
2001-09-08 20:58 ` [SMP lock BUG?] " Roger Larsson
2001-09-08 22:18 ` Arjan Filius
2001-09-09 14:55 ` george anzinger
2001-09-09 22:25 ` Arjan Filius
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