From: Matt Porter <mporter@kernel.crashing.org>
To: Marcelo Tosatti <marcelo.tosatti@cyclades.com>
Cc: Roland Dreier <rolandd@cisco.com>, linuxppc-embedded@ozlabs.org
Subject: Re: [PATCH] PPC: Don't sleep in flush_dcache_icache_page()
Date: Thu, 18 Aug 2005 11:08:21 -0700 [thread overview]
Message-ID: <20050818110821.M14235@cox.net> (raw)
In-Reply-To: <20050818175642.GA7523@dmt.cnet>; from marcelo.tosatti@cyclades.com on Thu, Aug 18, 2005 at 02:56:42PM -0300
On Thu, Aug 18, 2005 at 02:56:42PM -0300, Marcelo Tosatti wrote:
>
> Hi Roland,
>
> On Tue, Aug 16, 2005 at 01:56:49PM -0700, Roland Dreier wrote:
> > flush_dcache_icache_page() will be called on an instruction page
> > fault. We can't sleep in the fault handler, so use kmap_atomic()
> > instead of just kmap() for the Book-E case.
> >
> > Signed-off-by: Roland Dreier <rolandd@cisco.com>
>
> Why do you need to disable interrupts during the kmap_atomic/flush_dcache_icache
> operation ?
>
> I fail to see how an interrupt could have any reference to the data
> being dealt with here (the user page).
We just took care of this offline. The original patch is sharing
a kmap slot with another kmap_atomic user I put in before...the
sync page user. If an interrupt came in causing the DMA API to
be used, we would have a problem.
The clean solution was to use a different kmap slot.
-Matt
prev parent reply other threads:[~2005-08-18 18:08 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-08-16 20:56 [PATCH] PPC: Don't sleep in flush_dcache_icache_page() Roland Dreier
2005-08-18 17:56 ` Marcelo Tosatti
2005-08-18 18:08 ` Matt Porter [this message]
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