From: "H. Peter Anvin" <hpa@zytor.com>
To: Simon Jeons <simon.jeons@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>,
Sasha Levin <sasha.levin@oracle.com>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Andrew Morton <akpm@linux-foundation.org>,
David Rientjes <rientjes@google.com>,
Andrea Arcangeli <aarcange@redhat.com>,
Mel Gorman <mgorman@suse.de>, Dave Jones <davej@redhat.com>,
linux-mm <linux-mm@kvack.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: mm: BUG in do_huge_pmd_wp_page
Date: Thu, 25 Apr 2013 19:28:34 -0700 [thread overview]
Message-ID: <5179E652.808@zytor.com> (raw)
In-Reply-To: <51786D52.1080509@gmail.com>
On 04/24/2013 04:40 PM, Simon Jeons wrote:
>
> I see in memblock_trim_memory(): start = round_up(orig_start, align);
> here align is PAGE_SIZE, so the dump of zone ranges in my machine is [
> 0.000000] DMA [mem 0x00001000-0x00ffffff]. Why PFN 0 is not
> used? just for align?
>
PFN 0 contains the real-mode interrupt vector table and BIOS data area,
so we just reserve it. Avoids issues with zero being special, too.
-hpa
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WARNING: multiple messages have this Message-ID (diff)
From: "H. Peter Anvin" <hpa@zytor.com>
To: Simon Jeons <simon.jeons@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>,
Sasha Levin <sasha.levin@oracle.com>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Andrew Morton <akpm@linux-foundation.org>,
David Rientjes <rientjes@google.com>,
Andrea Arcangeli <aarcange@redhat.com>,
Mel Gorman <mgorman@suse.de>, Dave Jones <davej@redhat.com>,
linux-mm <linux-mm@kvack.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: mm: BUG in do_huge_pmd_wp_page
Date: Thu, 25 Apr 2013 19:28:34 -0700 [thread overview]
Message-ID: <5179E652.808@zytor.com> (raw)
In-Reply-To: <51786D52.1080509@gmail.com>
On 04/24/2013 04:40 PM, Simon Jeons wrote:
>
> I see in memblock_trim_memory(): start = round_up(orig_start, align);
> here align is PAGE_SIZE, so the dump of zone ranges in my machine is [
> 0.000000] DMA [mem 0x00001000-0x00ffffff]. Why PFN 0 is not
> used? just for align?
>
PFN 0 contains the real-mode interrupt vector table and BIOS data area,
so we just reserve it. Avoids issues with zero being special, too.
-hpa
next prev parent reply other threads:[~2013-04-26 2:28 UTC|newest]
Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-29 13:04 mm: BUG in do_huge_pmd_wp_page Sasha Levin
2013-03-29 13:04 ` Sasha Levin
2013-04-04 14:03 ` Sasha Levin
2013-04-04 14:03 ` Sasha Levin
2013-04-04 14:30 ` Kirill A. Shutemov
2013-04-04 14:30 ` Kirill A. Shutemov
2013-04-04 14:37 ` Sasha Levin
2013-04-04 14:37 ` Sasha Levin
2013-04-04 16:28 ` Kirill A. Shutemov
2013-04-04 16:28 ` Kirill A. Shutemov
2013-04-04 21:54 ` Sasha Levin
2013-04-04 21:54 ` Sasha Levin
2014-04-04 19:37 ` Sasha Levin
2014-04-04 19:37 ` Sasha Levin
2014-04-07 14:48 ` Kirill A. Shutemov
2014-04-07 14:56 ` Sasha Levin
2014-04-07 14:56 ` Sasha Levin
2014-04-07 19:40 ` Sasha Levin
2014-04-07 19:40 ` Sasha Levin
2014-04-07 20:11 ` Kirill A. Shutemov
2014-05-15 17:31 ` Sasha Levin
2014-05-15 17:31 ` Sasha Levin
2014-05-15 17:37 ` Hugh Dickins
2014-05-15 17:37 ` Hugh Dickins
2014-05-15 17:43 ` Sasha Levin
2014-05-15 17:43 ` Sasha Levin
2014-05-15 17:58 ` Hugh Dickins
2014-05-15 17:58 ` Hugh Dickins
2013-04-10 8:02 ` Minchan Kim
2013-04-10 8:02 ` Minchan Kim
2013-04-11 13:18 ` Kirill A. Shutemov
2013-04-11 13:18 ` Kirill A. Shutemov
2013-04-14 7:13 ` Minchan Kim
2013-04-14 7:13 ` Minchan Kim
2013-04-11 14:55 ` Sasha Levin
2013-04-11 14:55 ` Sasha Levin
2013-04-11 15:13 ` Kirill A. Shutemov
2013-04-11 15:13 ` Kirill A. Shutemov
2013-04-11 15:14 ` Sasha Levin
2013-04-24 22:46 ` Andrew Morton
2013-04-24 22:46 ` Andrew Morton
2013-04-26 0:51 ` Sasha Levin
2013-04-26 0:51 ` Sasha Levin
2013-04-26 2:01 ` Dave Jones
2013-04-26 2:01 ` Dave Jones
2013-04-26 3:12 ` Sasha Levin
2013-04-26 3:12 ` Sasha Levin
2014-02-04 3:01 ` Sasha Levin
2014-02-04 3:01 ` Sasha Levin
2014-02-04 3:59 ` Hugh Dickins
2014-02-04 3:59 ` Hugh Dickins
2014-02-04 16:58 ` Kirill A. Shutemov
2014-02-04 16:58 ` Kirill A. Shutemov
2014-02-05 18:12 ` Sasha Levin
2014-02-05 18:12 ` Sasha Levin
2014-02-05 22:50 ` Hugh Dickins
2014-02-05 22:50 ` Hugh Dickins
2013-04-24 22:51 ` H. Peter Anvin
2013-04-24 22:51 ` H. Peter Anvin
2013-04-24 23:40 ` Simon Jeons
2013-04-26 2:28 ` H. Peter Anvin [this message]
2013-04-26 2:28 ` H. Peter Anvin
2013-04-26 1:30 ` Minchan Kim
2013-04-26 1:30 ` Minchan Kim
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