From: Christoph Lameter <cl@linux-foundation.org>
To: Mike Travis <travis@sgi.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>,
Ingo Molnar <mingo@elte.hu>,
Andrew Morton <akpm@linux-foundation.org>,
"Eric W. Biederman" <ebiederm@xmission.com>,
"H. Peter Anvin" <hpa@zytor.com>, Jack Steiner <steiner@sgi.com>,
linux-kernel@vger.kernel.org
Subject: Re: [RFC 00/15] x86_64: Optimize percpu accesses
Date: Wed, 09 Jul 2008 13:13:24 -0500 [thread overview]
Message-ID: <4874FFC4.7050505@linux-foundation.org> (raw)
In-Reply-To: <4874FD52.8070000@sgi.com>
Mike Travis wrote:
> I think Jeremy's point is that by removing the pda struct entirely, the
> references to the fields can be the same for both x86_32 and x86_64.
That is going to be difficult. The GS register is tied up for the pda area
as long as you have it. And you cannot get rid of the pda because of the library
compatibility issues. We would break binary compatibility if we would get rid of the pda.
If one attempts to remove one field after another then the converted accesses will not be able to use GS relative accesses anymore. This can lead to all sorts of complications.
It will be possible to shrink the pda (as long as we maintain the fields that glibc needs) after this patchset because the pda and the per cpu area can both be reached with the GS register. So (apart from undiscovered surprises) the generated code is the same.
next prev parent reply other threads:[~2008-07-09 18:14 UTC|newest]
Thread overview: 190+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-07-09 16:51 [RFC 00/15] x86_64: Optimize percpu accesses Mike Travis
2008-07-09 16:51 ` [RFC 01/15] x86_64: Cleanup early setup_percpu references Mike Travis
2008-07-09 16:51 ` [RFC 02/15] x86_64: Fold pda into per cpu area Mike Travis
2008-07-09 22:02 ` Eric W. Biederman
2008-07-13 17:54 ` Ingo Molnar
2008-07-14 14:24 ` Mike Travis
2008-07-09 16:51 ` [RFC 03/15] x86_64: Reference zero-based percpu variables offset from gs Mike Travis
2008-07-09 16:51 ` [RFC 04/15] x86_64: Replace cpu_pda ops with percpu ops Mike Travis
2008-07-09 16:51 ` [RFC 05/15] x86_64: Replace xxx_pda() operations with x86_xxx_percpu() Mike Travis
2008-07-09 16:51 ` [RFC 06/15] x86_64: Replace xxx_pda() operations in include_asm-x86_current_h Mike Travis
2008-07-09 16:51 ` [RFC 07/15] x86_64: Replace xxx_pda() operations in include_asm-x86_hardirq_64_h Mike Travis
2008-07-09 16:51 ` [RFC 08/15] x86_64: Replace xxx_pda() operations in include_asm-x86_mmu_context_64_h Mike Travis
2008-07-09 16:51 ` [RFC 09/15] x86_64: Replace xxx_pda() operations in include_asm-x86_percpu_h Mike Travis
2008-07-09 16:51 ` [RFC 10/15] x86_64: Replace xxx_pda() operations in include_asm-x86_smp_h Mike Travis
2008-07-09 16:51 ` [RFC 11/15] x86_64: Replace xxx_pda() operations in include_asm-x86_stackprotector_h Mike Travis
2008-07-09 16:51 ` [RFC 12/15] x86_64: Replace xxx_pda() operations in include_asm-x86_thread_info_h Mike Travis
2008-07-09 16:51 ` [RFC 13/15] x86_64: Replace xxx_pda() operations in include_asm-x86_topology_h Mike Travis
2008-07-09 16:51 ` [RFC 14/15] x86_64: Remove xxx_pda() operations Mike Travis
2008-07-09 16:51 ` [RFC 15/15] x86_64: Remove cpu_pda() macro Mike Travis
2008-07-09 17:19 ` [RFC 00/15] x86_64: Optimize percpu accesses H. Peter Anvin
2008-07-09 17:40 ` Mike Travis
2008-07-09 17:42 ` H. Peter Anvin
2008-07-09 18:05 ` Mike Travis
2008-07-09 17:44 ` Jeremy Fitzhardinge
2008-07-09 18:09 ` Mike Travis
2008-07-09 18:30 ` H. Peter Anvin
2008-07-09 19:34 ` Ingo Molnar
2008-07-09 19:44 ` H. Peter Anvin
2008-07-09 20:26 ` Adrian Bunk
2008-07-09 21:03 ` Mike Travis
2008-07-09 21:23 ` Jeremy Fitzhardinge
2008-07-25 15:49 ` Mike Travis
2008-07-25 16:08 ` Jeremy Fitzhardinge
2008-07-25 16:46 ` Mike Travis
2008-07-25 16:58 ` Jeremy Fitzhardinge
2008-07-25 18:12 ` Mike Travis
2008-07-09 17:27 ` Jeremy Fitzhardinge
2008-07-09 17:39 ` Christoph Lameter
2008-07-09 17:51 ` Jeremy Fitzhardinge
2008-07-09 18:14 ` Mike Travis
2008-07-09 18:22 ` Jeremy Fitzhardinge
2008-07-09 18:31 ` Mike Travis
2008-07-09 19:08 ` Jeremy Fitzhardinge
2008-07-09 18:02 ` Mike Travis
2008-07-09 18:13 ` Christoph Lameter [this message]
2008-07-09 18:26 ` Jeremy Fitzhardinge
2008-07-09 18:34 ` Christoph Lameter
2008-07-09 18:37 ` H. Peter Anvin
2008-07-09 18:48 ` Jeremy Fitzhardinge
2008-07-09 18:53 ` Christoph Lameter
2008-07-09 19:07 ` Jeremy Fitzhardinge
2008-07-09 19:12 ` Christoph Lameter
2008-07-09 19:32 ` Jeremy Fitzhardinge
2008-07-09 19:41 ` Ingo Molnar
2008-07-09 19:45 ` H. Peter Anvin
2008-07-09 19:52 ` Christoph Lameter
2008-07-09 20:00 ` Ingo Molnar
2008-07-09 20:09 ` Jeremy Fitzhardinge
2008-07-09 21:05 ` Mike Travis
2008-07-09 19:44 ` Christoph Lameter
2008-07-09 19:48 ` Jeremy Fitzhardinge
2008-07-09 18:27 ` Mike Travis
2008-07-09 18:46 ` Jeremy Fitzhardinge
2008-07-09 20:22 ` Eric W. Biederman
2008-07-09 20:35 ` Jeremy Fitzhardinge
2008-07-09 20:53 ` Eric W. Biederman
2008-07-09 21:03 ` Ingo Molnar
2008-07-09 21:16 ` H. Peter Anvin
2008-07-09 21:10 ` Arjan van de Ven
2008-07-09 23:20 ` Eric W. Biederman
2008-07-09 18:31 ` H. Peter Anvin
2008-07-09 18:00 ` Mike Travis
2008-07-09 19:05 ` Jeremy Fitzhardinge
2008-07-09 19:28 ` Ingo Molnar
2008-07-09 20:55 ` Mike Travis
2008-07-09 21:12 ` Ingo Molnar
2008-07-09 20:00 ` Eric W. Biederman
2008-07-09 20:05 ` Jeremy Fitzhardinge
2008-07-09 20:15 ` Ingo Molnar
2008-07-09 20:07 ` Ingo Molnar
2008-07-09 20:11 ` Jeremy Fitzhardinge
2008-07-09 20:18 ` Christoph Lameter
2008-07-09 20:33 ` Jeremy Fitzhardinge
2008-07-09 20:42 ` H. Peter Anvin
2008-07-09 20:48 ` Jeremy Fitzhardinge
2008-07-09 21:06 ` Eric W. Biederman
2008-07-09 21:16 ` H. Peter Anvin
2008-07-09 21:20 ` Jeremy Fitzhardinge
2008-07-09 21:25 ` Christoph Lameter
2008-07-09 21:36 ` H. Peter Anvin
2008-07-09 21:41 ` Jeremy Fitzhardinge
2008-07-09 22:22 ` Eric W. Biederman
2008-07-09 22:32 ` Jeremy Fitzhardinge
2008-07-09 23:36 ` Eric W. Biederman
2008-07-10 0:19 ` H. Peter Anvin
2008-07-10 0:24 ` Jeremy Fitzhardinge
2008-07-10 14:14 ` Christoph Lameter
2008-07-10 14:26 ` H. Peter Anvin
2008-07-10 15:26 ` Christoph Lameter
2008-07-10 15:42 ` H. Peter Anvin
2008-07-10 16:24 ` Christoph Lameter
2008-07-10 16:33 ` H. Peter Anvin
2008-07-10 16:45 ` Christoph Lameter
2008-07-10 17:33 ` Jeremy Fitzhardinge
2008-07-10 17:42 ` Christoph Lameter
2008-07-10 17:53 ` Jeremy Fitzhardinge
2008-07-10 17:55 ` H. Peter Anvin
2008-07-10 20:52 ` Christoph Lameter
2008-07-10 20:58 ` Jeremy Fitzhardinge
2008-07-10 21:03 ` H. Peter Anvin
2008-07-11 0:55 ` Mike Travis
2008-07-10 21:05 ` Christoph Lameter
2008-07-10 21:22 ` Eric W. Biederman
2008-07-10 21:29 ` H. Peter Anvin
2008-07-11 0:12 ` Mike Travis
2008-07-11 0:14 ` H. Peter Anvin
2008-07-11 0:58 ` Mike Travis
2008-07-11 1:41 ` H. Peter Anvin
2008-07-11 15:37 ` Christoph Lameter
2008-07-11 0:42 ` Eric W. Biederman
2008-07-11 15:36 ` Christoph Lameter
2008-07-10 17:53 ` H. Peter Anvin
2008-07-10 17:26 ` Eric W. Biederman
2008-07-10 17:38 ` Christoph Lameter
2008-07-10 19:11 ` Mike Travis
2008-07-10 19:12 ` Eric W. Biederman
2008-07-10 17:46 ` Mike Travis
2008-07-10 17:51 ` H. Peter Anvin
2008-07-10 19:09 ` Eric W. Biederman
2008-07-10 19:18 ` Mike Travis
2008-07-10 19:32 ` H. Peter Anvin
2008-07-10 23:37 ` Mike Travis
2008-07-10 20:17 ` Eric W. Biederman
2008-07-10 20:24 ` Ingo Molnar
2008-07-10 21:33 ` Eric W. Biederman
2008-07-11 1:39 ` Mike Travis
2008-07-11 2:57 ` Eric W. Biederman
2008-07-10 0:23 ` Jeremy Fitzhardinge
2008-07-09 20:35 ` H. Peter Anvin
2008-07-09 20:39 ` Arjan van de Ven
2008-07-09 20:44 ` H. Peter Anvin
2008-07-09 20:50 ` Jeremy Fitzhardinge
2008-07-09 21:12 ` H. Peter Anvin
2008-07-09 21:26 ` Jeremy Fitzhardinge
2008-07-09 21:37 ` H. Peter Anvin
2008-07-09 22:10 ` Eric W. Biederman
2008-07-09 22:23 ` H. Peter Anvin
2008-07-09 23:54 ` Eric W. Biederman
2008-07-10 16:22 ` Mike Travis
2008-07-10 16:25 ` H. Peter Anvin
2008-07-10 16:35 ` Christoph Lameter
2008-07-10 16:39 ` H. Peter Anvin
2008-07-10 16:47 ` Christoph Lameter
2008-07-10 17:21 ` Jeremy Fitzhardinge
2008-07-10 17:31 ` Christoph Lameter
2008-07-10 17:48 ` Jeremy Fitzhardinge
2008-07-10 18:00 ` H. Peter Anvin
2008-07-10 17:20 ` Mike Travis
2008-07-10 17:07 ` Jeremy Fitzhardinge
2008-07-10 17:12 ` Christoph Lameter
2008-07-10 17:25 ` Jeremy Fitzhardinge
2008-07-10 17:34 ` Christoph Lameter
2008-07-10 17:41 ` Mike Travis
2008-07-10 18:01 ` H. Peter Anvin
2008-07-10 20:51 ` Christoph Lameter
2008-07-10 20:58 ` H. Peter Anvin
2008-07-10 21:07 ` Christoph Lameter
2008-07-10 21:11 ` H. Peter Anvin
2008-07-11 15:32 ` Christoph Lameter
2008-07-11 16:07 ` H. Peter Anvin
2008-07-11 16:57 ` Eric W. Biederman
2008-07-11 17:10 ` H. Peter Anvin
2008-07-10 21:26 ` Eric W. Biederman
2008-07-10 18:48 ` Eric W. Biederman
2008-07-10 18:54 ` Jeremy Fitzhardinge
2008-07-10 19:18 ` Eric W. Biederman
2008-07-10 19:56 ` Jeremy Fitzhardinge
2008-07-10 20:22 ` Eric W. Biederman
2008-07-10 20:54 ` Jeremy Fitzhardinge
2008-07-11 6:59 ` Rusty Russell
2008-07-10 20:25 ` Eric W. Biederman
2008-07-10 17:57 ` H. Peter Anvin
2008-07-10 18:08 ` H. Peter Anvin
2008-07-09 20:46 ` Jeremy Fitzhardinge
2008-07-09 20:14 ` Arjan van de Ven
2008-07-09 20:33 ` Eric W. Biederman
2008-07-09 21:01 ` Ingo Molnar
2008-07-09 21:39 ` Mike Travis
2008-07-09 21:47 ` Jeremy Fitzhardinge
2008-07-09 21:55 ` Eric W. Biederman
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