From: Christoph Lameter <cl@linux-foundation.org>
To: David VomLehn <dvomlehn@cisco.com>
Cc: Randy Dunlap <rdunlap@xenotime.net>,
C Michael Sundius <Michael.sundius@sciatl.com>,
Dave Hansen <dave@linux.vnet.ibm.com>,
Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
linux-mm@kvack.org, linux-mips@linux-mips.org,
jfraser@broadcom.com, Andy Whitcroft <apw@shadowen.org>
Subject: Re: sparsemem support for mips with highmem
Date: Tue, 19 Aug 2008 08:06:21 -0500 [thread overview]
Message-ID: <48AAC54D.8020609@linux-foundation.org> (raw)
In-Reply-To: <48A9F047.7050906@cisco.com>
David VomLehn wrote:
> On MIPS processors, the kernel runs in unmapped memory, i.e. the TLB
> isn't even
> used, so I don't think you can use that trick. So, this comment doesn't
> apply to
> all processors.
In that case you have a choice between the overhead of sparsemem lookups in
every pfn_to_page or using TLB entries to create a virtually mapped memmap
which may create TLB pressure.
The virtually mapped memmap results in smaller code and is typically more
effective since the processor caches the TLB entries.
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Lameter <cl@linux-foundation.org>
To: David VomLehn <dvomlehn@cisco.com>
Cc: Randy Dunlap <rdunlap@xenotime.net>,
C Michael Sundius <Michael.sundius@sciatl.com>,
Dave Hansen <dave@linux.vnet.ibm.com>,
Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
linux-mm@kvack.org, linux-mips@linux-mips.org,
jfraser@broadcom.com, Andy Whitcroft <apw@shadowen.org>
Subject: Re: sparsemem support for mips with highmem
Date: Tue, 19 Aug 2008 08:06:21 -0500 [thread overview]
Message-ID: <48AAC54D.8020609@linux-foundation.org> (raw)
In-Reply-To: <48A9F047.7050906@cisco.com>
David VomLehn wrote:
> On MIPS processors, the kernel runs in unmapped memory, i.e. the TLB
> isn't even
> used, so I don't think you can use that trick. So, this comment doesn't
> apply to
> all processors.
In that case you have a choice between the overhead of sparsemem lookups in
every pfn_to_page or using TLB entries to create a virtually mapped memmap
which may create TLB pressure.
The virtually mapped memmap results in smaller code and is typically more
effective since the processor caches the TLB entries.
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next prev parent reply other threads:[~2008-08-19 13:07 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-08-14 22:05 sparsemem support for mips with highmem C Michael Sundius
2008-08-14 22:35 ` Dave Hansen
2008-08-14 22:35 ` Dave Hansen
2008-08-14 23:16 ` C Michael Sundius
2008-08-14 23:16 ` C Michael Sundius
2008-08-14 23:52 ` C Michael Sundius
2008-08-15 0:02 ` Dave Hansen
2008-08-15 0:02 ` Dave Hansen
2008-08-15 8:03 ` Thomas Bogendoerfer
2008-08-15 8:03 ` Thomas Bogendoerfer
2008-08-15 15:48 ` Dave Hansen
2008-08-15 15:48 ` Dave Hansen
2008-08-15 16:12 ` C Michael Sundius
2008-08-15 16:12 ` C Michael Sundius
2008-08-15 16:20 ` Dave Hansen
2008-08-15 16:20 ` Dave Hansen
2008-08-15 16:33 ` Thomas Bogendoerfer
2008-08-15 16:33 ` Thomas Bogendoerfer
2008-08-15 17:16 ` C Michael Sundius
2008-08-15 17:16 ` C Michael Sundius
2008-08-15 17:37 ` Dave Hansen
2008-08-15 17:37 ` Dave Hansen
2008-08-15 18:17 ` C Michael Sundius
2008-08-15 18:17 ` C Michael Sundius
2008-08-15 18:23 ` Dave Hansen
2008-08-15 18:23 ` Dave Hansen
2008-08-16 20:07 ` Thomas Bogendoerfer
2008-08-16 20:07 ` Thomas Bogendoerfer
2008-08-18 16:44 ` Randy Dunlap
2008-08-18 16:44 ` Randy Dunlap
2008-08-18 21:24 ` Christoph Lameter
2008-08-18 21:24 ` Christoph Lameter
2008-08-18 21:27 ` Dave Hansen
2008-08-18 21:27 ` Dave Hansen
2008-08-18 21:33 ` Christoph Lameter
2008-08-18 21:33 ` Christoph Lameter
2009-01-16 21:46 ` Michael Sundius
2009-01-16 21:46 ` Michael Sundius
2009-01-21 14:39 ` Christoph Lameter
2009-01-21 14:39 ` Christoph Lameter
2008-08-18 21:57 ` David VomLehn
2008-08-18 21:57 ` David VomLehn
2008-08-19 13:06 ` Christoph Lameter [this message]
2008-08-19 13:06 ` Christoph Lameter
2008-08-19 23:38 ` David VomLehn
2008-08-19 23:38 ` David VomLehn
2008-08-19 23:53 ` Jon Fraser
2008-08-19 23:53 ` Jon Fraser
2008-08-20 13:58 ` Christoph Lameter
2008-08-20 13:58 ` Christoph Lameter
2008-08-20 19:28 ` David VomLehn
2008-08-20 19:28 ` David VomLehn
2008-08-20 20:51 ` Christoph Lameter
2008-08-20 20:51 ` Christoph Lameter
2008-08-15 16:30 ` Thomas Bogendoerfer
2008-08-15 16:30 ` Thomas Bogendoerfer
2008-08-26 9:09 ` Andy Whitcroft
2008-08-26 9:09 ` Andy Whitcroft
2008-10-06 20:15 ` Have ever checked in your mips sparsemem code into mips-linux tree? C Michael Sundius
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