From: Ralf Baechle <ralf@linux-mips.org>
To: Minchan Kim <minchan.kim@gmail.com>
Cc: Atsushi Nemoto <anemo@mba.ocn.ne.jp>,
lkml <linux-kernel@vger.kernel.org>,
linux-mips <linux-mips@linux-mips.org>,
Chungki woo <chungki.woo@gmail.com>
Subject: Re: BUG? linux-mips flush_dcache_page
Date: Fri, 16 Oct 2009 11:24:18 +0200 [thread overview]
Message-ID: <20091016092418.GA3686@linux-mips.org> (raw)
In-Reply-To: <20091016141719.de606482.minchan.kim@barrios-desktop>
On Fri, Oct 16, 2009 at 02:17:19PM +0900, Minchan Kim wrote:
> Many code of kernel fs usually allocate high page and flush.
> But flush_dcache_page of mips checks PageHighMem to avoid flush
> so that data consistency is broken, I think.
What processor and cache configuration?
> I found it's by you and Atsushi-san on 585fa724.
> Why do we need the check?
> Could you elaborte please?
The if statement exists because __flush_dcache_page would crash if a page
is not mapped. This of course isn't correct but that wasn't a problem
since highmem still is only supported on machines that don't have aliases.
Ralf
next prev parent reply other threads:[~2009-10-16 9:23 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-10-16 5:17 BUG? linux-mips flush_dcache_page Minchan Kim
2009-10-16 9:24 ` Ralf Baechle [this message]
2009-10-16 10:43 ` Minchan Kim
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