From: Rik van Riel <riel@redhat.com>
To: rwhitton@iee.org
Cc: linux-kernel@vger.kernel.org
Subject: Re: Background memory scrubbing
Date: Wed, 20 Apr 2011 12:45:30 -0400 [thread overview]
Message-ID: <4DAF0DAA.5080608@redhat.com> (raw)
In-Reply-To: <42558.1303286300@jupiter.eclipse.co.uk>
On 04/20/2011 03:58 AM, Robert Whitton wrote:
> for each PFN from 256 to the highest valid PFN
> {
> if (pfn_valid(PFN))
> {
> page = pfn_to_page(PFN)
> va = kmap(page)
> atomic_scrub(va, PAGE_SIZE)
> kunmap(page)
> }
>
> sleep(for_a_while)
> }
What exactly does atomic_scrub do?
> This code works absolutely fine up to a short distance beyond the 16MB boundary (specifically it seems to always fail on my hardware at PFN 4105). At this point despite the fact that kmap returns a valid virtual address (and it is the virtual address that I expect - 0xffff880001009000) I get the kernel oops - "unable to handle kernel paging request".
Looks like you might be making some of the kernel code that
is running at that moment unreachable, leading to a kernel
page fault.
next prev parent reply other threads:[~2011-04-20 16:45 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-20 7:58 Background memory scrubbing Robert Whitton
2011-04-20 13:30 ` Clemens Ladisch
2011-04-20 16:45 ` Rik van Riel [this message]
-- strict thread matches above, loose matches on Subject: below --
2011-04-20 14:40 Robert Whitton
2011-04-20 15:19 ` Clemens Ladisch
2011-04-20 15:35 ` Borislav Petkov
2011-04-20 15:46 ` Markus Trippelsdorf
2011-04-20 15:58 ` Borislav Petkov
2011-04-20 16:45 ` Markus Trippelsdorf
2011-04-20 16:55 ` Markus Trippelsdorf
2011-04-20 17:36 ` Borislav Petkov
2011-04-20 19:23 ` Bill Gatliff
2011-04-20 15:46 Robert Whitton
2011-04-20 16:01 ` Borislav Petkov
2011-04-20 16:01 ` Borislav Petkov
2011-04-25 16:53 ` Chris Friesen
2011-04-25 16:53 ` Chris Friesen
2011-04-20 17:05 Robert Whitton
2011-04-20 17:53 ` Rik van Riel
2011-04-24 20:47 ` Pavel Machek
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