From: Andi Kleen <ak@muc.de>
To: Christoph Lameter <clameter@sgi.com>
Cc: linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: page fault fastpath: Increasing SMP scalability by introducing
Date: Sun, 15 Aug 2004 23:53:09 +0000 [thread overview]
Message-ID: <m31xi8dkm2.fsf@averell.firstfloor.org> (raw)
In-Reply-To: <2tCiw-8pK-1@gated-at.bofh.it> (Christoph Lameter's message of "Mon, 16 Aug 2004 01:10:04 +0200")
Christoph Lameter <clameter@sgi.com> writes:
> On Sun, 15 Aug 2004, David S. Miller wrote:
>
>>
>> Is the read lock in the VMA semaphore enough to let you do
>> the pgd/pmd walking without the page_table_lock?
>> I think it is, but just checking.
>
> That would be great.... May I change the page_table lock to
> be a read write spinlock instead?
That's probably not a good idea. r/w locks are extremly slow on
some architectures. Including ia64.
Just profile cat /proc/net/tcp on a machine with a lot of memory
and you'll notice.
-Andi
WARNING: multiple messages have this Message-ID (diff)
From: Andi Kleen <ak@muc.de>
To: Christoph Lameter <clameter@sgi.com>
Cc: linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: page fault fastpath: Increasing SMP scalability by introducing pte locks?
Date: Mon, 16 Aug 2004 01:53:09 +0200 [thread overview]
Message-ID: <m31xi8dkm2.fsf@averell.firstfloor.org> (raw)
In-Reply-To: <2tCiw-8pK-1@gated-at.bofh.it> (Christoph Lameter's message of "Mon, 16 Aug 2004 01:10:04 +0200")
Christoph Lameter <clameter@sgi.com> writes:
> On Sun, 15 Aug 2004, David S. Miller wrote:
>
>>
>> Is the read lock in the VMA semaphore enough to let you do
>> the pgd/pmd walking without the page_table_lock?
>> I think it is, but just checking.
>
> That would be great.... May I change the page_table lock to
> be a read write spinlock instead?
That's probably not a good idea. r/w locks are extremly slow on
some architectures. Including ia64.
Just profile cat /proc/net/tcp on a machine with a lot of memory
and you'll notice.
-Andi
next parent reply other threads:[~2004-08-15 23:53 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <2ttIr-2e4-17@gated-at.bofh.it>
[not found] ` <2tzE4-6sw-25@gated-at.bofh.it>
[not found] ` <2tCiw-8pK-1@gated-at.bofh.it>
2004-08-15 23:53 ` Andi Kleen [this message]
2004-08-15 23:53 ` page fault fastpath: Increasing SMP scalability by introducing pte locks? Andi Kleen
2004-08-15 23:55 ` page fault fastpath: Increasing SMP scalability by introducing Christoph Lameter
2004-08-15 23:55 ` page fault fastpath: Increasing SMP scalability by introducing pte locks? Christoph Lameter
2004-08-16 0:12 ` Andi Kleen
2004-08-16 0:12 ` Andi Kleen
2004-08-15 13:50 page fault fastpath: Increasing SMP scalability by introducing pte Christoph Lameter
2004-08-15 20:09 ` page fault fastpath: Increasing SMP scalability by introducing David S. Miller
2004-08-15 22:58 ` Christoph Lameter
2004-08-15 23:58 ` David S. Miller
2004-08-16 0:11 ` Christoph Lameter
2004-08-16 1:56 ` David S. Miller
2004-08-16 3:29 ` Christoph Lameter
2004-08-16 6:59 ` Ray Bryant
2004-08-16 15:18 ` Christoph Lameter
2004-08-15 22:38 ` Benjamin Herrenschmidt
2004-08-16 17:28 ` Christoph Lameter
2004-08-17 8:01 ` Benjamin Herrenschmidt
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=m31xi8dkm2.fsf@averell.firstfloor.org \
--to=ak@muc.de \
--cc=clameter@sgi.com \
--cc=linux-ia64@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.