From: Christoph Lameter <clameter@sgi.com>
To: Andi Kleen <ak@muc.de>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>,
Andrew Morton <akpm@osdl.org>,
torvalds@osdl.org, hugh@veritas.com, linux-mm@kvack.org,
linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org,
benh@kernel.crashing.org
Subject: page fault scalability patch V16 [0/4]: redesign overview
Date: Fri, 28 Jan 2005 12:35:11 -0800 (PST) [thread overview]
Message-ID: <Pine.LNX.4.58.0501281233560.19266@schroedinger.engr.sgi.com> (raw)
In-Reply-To: <20050114170140.GB4634@muc.de>
Changes from V15->V16 of this patch: Complete Redesign.
An introduction to what this patch does and a patch archive can be found on
http://oss.sgi.com/projects/page_fault_performance. The archive also has a
combined patch.
The basic approach in this patchset is the same as used in SGI's 2.4.X
based kernels which have been in production use in ProPack 3 for a long time.
The patchset is composed of 4 patches (and was tested against 2.6.11-rc2-bk6
on ia64, i386 and x86_64):
1/4: ptep_cmpxchg and ptep_xchg to avoid intermittent zeroing of ptes
The current way of synchronizing with the CPU or arch specific
interrupts updating page table entries is to first set a pte
to zero before writing a new value. This patch uses ptep_xchg
and ptep_cmpxchg to avoid writing the zero for certain
configurations.
The patch introduces CONFIG_ATOMIC_TABLE_OPS that may be
enabled as a experimental feature during kernel configuration
if the hardware is able to support atomic operations and if
an SMP kernel is being configured. A Kconfig update for i386,
x86_64 and ia64 has been provided. On i386 this options is
restricted to CPUs better than a 486 and non PAE mode (that
way all the cmpxchg issues on old i386 CPUS and the problems
with 64bit atomic operations on recent i386 CPUS are avoided).
If CONFIG_ATOMIC_TABLE_OPS is not set then ptep_xchg and
ptep_xcmpxchg are realized by falling back to clearing a pte
before updating it.
The patch does not change the use of mm->page_table_lock and
the only performance improvement is the replacement of
xchg-with-zero-and-then-write-new-pte-value with an xchg with
the new value for SMP on some architectures if
CONFIG_ATOMIC_TABLE_OPS is configured. It should not do anything
major to VM operations.
2/4: Macros for mm counter manipulation
There are various approaches to handling mm counters if the
page_table_lock is no longer acquired. This patch defines
macros in include/linux/sched.h to handle these counters and
makes sure that these macros are used throughout the kernel
to access and manipulate rss and anon_rss. There should be
no change to the generated code as a result of this patch.
3/4: Drop the first use of the page_table_lock in handle_mm_fault
The patch introduces two new functions:
page_table_atomic_start(mm), page_table_atomic_stop(mm)
that fall back to the use of the page_table_lock if
CONFIG_ATOMIC_TABLE_OPS is not defined.
If CONFIG_ATOMIC_TABLE_OPS is defined those functions may
be used to prep the CPU for atomic table ops (i386 in PAE mode
may f.e. get the MMX register ready for 64bit atomic ops) but
are simply empty by default.
Two operations may then be performed on the page table without
acquiring the page table lock:
a) updating access bits in pte
b) anonymous read faults installed a mapping to the zero page.
All counters are still protected with the page_table_lock thus
avoiding any issues there.
Some additional statistics are added to /proc/meminfo to
give some statistics. Also counts spurious faults with no
effect. There is a surprisingly high number of those on ia64
(used to populate the cpu caches with the pte??)
4/4: Drop the use of the page_table_lock in do_anonymous_page
The second acquisition of the page_table_lock is removed
from do_anonymous_page and allows the anonymous
write fault to be possible without the page_table_lock.
The macros for manipulating rss and anon_rss in include/linux/sched.h
are changed if CONFIG_ATOMIC_TABLE_OPS is set to use atomic
operations for rss and anon_rss (safest solution for now, other
solutions may easily be implemented by changing those macros).
This patch typically yield significant increases in page fault
performance for threaded applications on SMP systems.
I have an additional patch that drops the page_table_lock for COW but that
raises a lot of other issues. I will post that patch separately and only
to linux-mm.
next prev parent reply other threads:[~2005-01-28 20:41 UTC|newest]
Thread overview: 286+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <Pine.LNX.4.44.0411061527440.3567-100000@localhost.localdomain>
[not found] ` <Pine.LNX.4.58.0411181126440.30385@schroedinger.engr.sgi.com>
[not found] ` <Pine.LNX.4.58.0411181715280.834@schroedinger.engr.sgi.com>
[not found] ` <419D581F.2080302@yahoo.com.au>
[not found] ` <Pine.LNX.4.58.0411181835540.1421@schroedinger.engr.sgi.com>
[not found] ` <419D5E09.20805@yahoo.com.au>
[not found] ` <Pine.LNX.4.58.0411181921001.1674@schroedinger.engr.sgi.com>
[not found] ` <1100848068.25520.49.camel@gaston>
2004-11-19 19:42 ` page fault scalability patch V11 [0/7]: overview Christoph Lameter
2004-11-19 19:43 ` page fault scalability patch V11 [1/7]: sloppy rss Christoph Lameter
2004-11-19 20:50 ` Hugh Dickins
2004-11-20 1:29 ` Christoph Lameter
2004-11-22 15:00 ` Hugh Dickins
2004-11-22 21:50 ` deferred rss update instead of " Christoph Lameter
2004-11-22 22:11 ` Andrew Morton
2004-11-22 22:13 ` Christoph Lameter
2004-11-22 22:17 ` Benjamin Herrenschmidt
2004-11-22 22:45 ` Andrew Morton
2004-11-22 22:48 ` Christoph Lameter
2004-11-22 23:09 ` Nick Piggin
2004-11-22 23:13 ` Christoph Lameter
2004-11-22 23:16 ` Andrew Morton
2004-11-22 23:19 ` Christoph Lameter
2004-11-22 22:22 ` Linus Torvalds
2004-11-22 22:27 ` Christoph Lameter
2004-11-22 22:40 ` Linus Torvalds
2004-12-01 23:41 ` page fault scalability patch V12 [0/7]: Overview and performance tests Christoph Lameter
2004-12-01 23:42 ` page fault scalability patch V12 [1/7]: Reduce use of thepage_table_lock Christoph Lameter
2004-12-01 23:42 ` page fault scalability patch V12 [2/7]: atomic pte operations for ia64 Christoph Lameter
2004-12-01 23:43 ` page fault scalability patch V12 [3/7]: universal cmpxchg for i386 Christoph Lameter
2004-12-01 23:43 ` page fault scalability patch V12 [4/7]: atomic pte operations " Christoph Lameter
2004-12-01 23:44 ` page fault scalability patch V12 [5/7]: atomic pte operations for x86_64 Christoph Lameter
2004-12-01 23:45 ` page fault scalability patch V12 [6/7]: atomic pte operations for s390 Christoph Lameter
2004-12-01 23:45 ` page fault scalability patch V12 [7/7]: Split counter for rss Christoph Lameter
2005-01-04 19:35 ` page fault scalability patch V14 [0/7]: Overview Christoph Lameter
2005-01-04 19:35 ` page fault scalability patch V14 [1/7]: Avoid taking page_table_lock Christoph Lameter
2005-01-04 19:36 ` page fault scalability patch V14 [2/7]: ia64 atomic pte operations Christoph Lameter
2005-01-04 19:37 ` page fault scalability patch V14 [3/7]: i386 universal cmpxchg Christoph Lameter
2005-01-05 11:51 ` Roman Zippel
2005-01-04 19:37 ` page fault scalability patch V14 [4/7]: i386 atomic pte operations Christoph Lameter
2005-01-04 19:38 ` page fault scalability patch V14 [5/7]: x86_64 " Christoph Lameter
2005-01-04 19:46 ` Andi Kleen
2005-01-04 19:58 ` Christoph Lameter
2005-01-04 20:21 ` Andi Kleen
2005-01-04 20:32 ` Christoph Lameter
2005-01-11 17:39 ` page table lock patch V15 [0/7]: overview Christoph Lameter
2005-01-11 17:40 ` page table lock patch V15 [1/7]: Reduce use of page table lock Christoph Lameter
2005-01-11 17:41 ` page table lock patch V15 [2/7]: ia64 atomic pte operations Christoph Lameter
2005-01-11 17:41 ` page table lock patch V15 [3/7]: i386 universal cmpxchg Christoph Lameter
2005-01-11 17:42 ` page table lock patch V15 [4/7]: i386 atomic pte operations Christoph Lameter
2005-01-11 17:43 ` page table lock patch V15 [5/7]: x86_64 " Christoph Lameter
2005-01-11 17:43 ` page table lock patch V15 [6/7]: s390 " Christoph Lameter
2005-01-11 17:44 ` page table lock patch V15 [7/7]: Split RSS counter Christoph Lameter
2005-01-12 5:59 ` page table lock patch V15 [0/7]: overview Nick Piggin
2005-01-12 9:42 ` Andrew Morton
2005-01-12 12:29 ` Marcelo Tosatti
2005-01-12 12:43 ` Hugh Dickins
2005-01-12 21:22 ` Hugh Dickins
2005-01-12 23:52 ` Christoph Lameter
2005-01-13 2:52 ` Hugh Dickins
2005-01-13 17:05 ` Christoph Lameter
2005-01-12 16:39 ` Christoph Lameter
2005-01-12 16:49 ` Christoph Hellwig
2005-01-12 17:37 ` Christoph Lameter
2005-01-12 17:41 ` Christoph Hellwig
2005-01-12 17:52 ` Christoph Lameter
2005-01-12 18:04 ` Christoph Hellwig
2005-01-12 18:20 ` Andrew Walrond
2005-01-12 18:43 ` Andrew Morton
2005-01-12 19:06 ` Christoph Lameter
2005-01-14 3:39 ` Roman Zippel
2005-01-14 4:14 ` Andi Kleen
2005-01-14 12:02 ` Roman Zippel
2005-01-12 23:16 ` Nick Piggin
2005-01-12 23:30 ` Andrew Morton
2005-01-12 23:50 ` Nick Piggin
2005-01-12 23:54 ` Christoph Lameter
2005-01-13 0:10 ` Nick Piggin
2005-01-13 0:16 ` Christoph Lameter
2005-01-13 0:42 ` Nick Piggin
2005-01-13 22:19 ` Peter Chubb
2005-01-13 3:18 ` Andi Kleen
2005-01-13 17:11 ` Christoph Lameter
2005-01-13 17:25 ` Linus Torvalds
2005-01-13 18:02 ` Andi Kleen
2005-01-13 18:16 ` Christoph Lameter
2005-01-13 20:17 ` Andi Kleen
2005-01-14 1:09 ` Christoph Lameter
2005-01-14 4:39 ` Andi Kleen
2005-01-14 4:52 ` page table lock patch V15 [0/7]: overview II Andi Kleen
2005-01-14 4:59 ` Nick Piggin
2005-01-14 10:47 ` Andi Kleen
2005-01-14 10:57 ` Nick Piggin
2005-01-14 11:11 ` Andi Kleen
2005-01-14 16:57 ` Christoph Lameter
2005-01-14 4:54 ` page table lock patch V15 [0/7]: overview Nick Piggin
2005-01-14 10:46 ` Andi Kleen
2005-01-14 16:52 ` Christoph Lameter
2005-01-14 17:01 ` Andi Kleen
2005-01-14 17:08 ` Christoph Lameter
2005-01-14 17:11 ` Andi Kleen
2005-01-14 17:43 ` Linus Torvalds
2005-01-28 20:35 ` Christoph Lameter [this message]
2005-01-28 20:36 ` page fault scalability patch V16 [1/4]: avoid intermittent clearing of ptes Christoph Lameter
2005-01-28 20:36 ` page fault scalability patch V16 [2/4]: mm counter macros Christoph Lameter
2005-01-28 20:37 ` page fault scalability patch V16 [3/4]: Drop page_table_lock in handle_mm_fault Christoph Lameter
2005-02-01 4:08 ` Nick Piggin
2005-02-01 18:47 ` Christoph Lameter
2005-02-01 19:01 ` Christoph Lameter
2005-02-02 0:31 ` Nick Piggin
2005-02-02 1:20 ` Christoph Lameter
2005-02-02 1:41 ` Nick Piggin
2005-02-02 2:49 ` Christoph Lameter
2005-02-02 3:09 ` Nick Piggin
2005-02-04 6:27 ` Nick Piggin
2005-02-17 0:57 ` page fault scalability patchsets update: prezeroing, prefaulting and atomic operations Christoph Lameter
2005-02-24 6:04 ` A Proposal for an MMU abstraction layer Christoph Lameter
2005-02-01 4:16 ` page fault scalability patch V16 [3/4]: Drop page_table_lock in handle_mm_fault Nick Piggin
2005-02-01 8:20 ` Kernel 2.4.21 hangs up baswaraj kasture
2005-02-01 8:35 ` Arjan van de Ven
2005-02-01 9:03 ` Christian Hildner
2005-02-07 6:14 ` Kernel 2.4.21 gives kernel panic at boot time baswaraj kasture
2005-02-01 17:46 ` Kernel 2.4.21 hangs up David Mosberger
2005-02-01 17:54 ` Markus Trippelsdorf
2005-02-01 18:08 ` David Mosberger
2005-02-01 18:44 ` page fault scalability patch V16 [3/4]: Drop page_table_lock in handle_mm_fault Christoph Lameter
2005-01-28 20:38 ` page fault scalability patch V16 [4/4]: Drop page_table_lock in do_anonymous_page Christoph Lameter
2005-01-13 3:09 ` page table lock patch V15 [0/7]: overview Hugh Dickins
2005-01-13 3:46 ` Nick Piggin
2005-01-13 17:14 ` Christoph Lameter
2005-01-04 21:21 ` page fault scalability patch V14 [5/7]: x86_64 atomic pte operations Brian Gerst
2005-01-04 21:26 ` Christoph Lameter
2005-01-04 19:38 ` page fault scalability patch V14 [6/7]: s390 atomic pte operationsw Christoph Lameter
2005-01-04 19:39 ` page fault scalability patch V14 [7/7]: Split RSS counters Christoph Lameter
2004-12-02 0:10 ` page fault scalability patch V12 [0/7]: Overview and performance tests Linus Torvalds
2004-12-02 0:55 ` Andrew Morton
2004-12-02 1:46 ` Christoph Lameter
2004-12-02 6:21 ` Jeff Garzik
2004-12-02 6:34 ` Andrew Morton
2004-12-02 6:48 ` Jeff Garzik
2004-12-02 7:02 ` Andrew Morton
2004-12-02 7:26 ` Martin J. Bligh
2004-12-02 7:31 ` Jeff Garzik
2004-12-02 18:10 ` cliff white
2004-12-02 18:17 ` Gerrit Huizenga
2004-12-02 20:25 ` linux-os
2004-12-08 17:24 ` Anticipatory prefaulting in the page fault handler V1 Christoph Lameter
2004-12-08 17:33 ` Jesse Barnes
2004-12-08 17:56 ` Christoph Lameter
2004-12-08 18:33 ` Jesse Barnes
2004-12-08 21:26 ` David S. Miller
2004-12-08 21:42 ` Linus Torvalds
2004-12-08 17:55 ` Dave Hansen
2004-12-08 19:07 ` Martin J. Bligh
2004-12-08 22:50 ` Martin J. Bligh
2004-12-09 19:32 ` Christoph Lameter
2004-12-10 2:13 ` [OT:HUMOR] " Adam Heath
2004-12-13 14:30 ` Akinobu Mita
2004-12-13 17:10 ` Christoph Lameter
2004-12-13 22:16 ` Martin J. Bligh
2004-12-14 1:32 ` Anticipatory prefaulting in the page fault handler V2 Christoph Lameter
2004-12-14 19:31 ` Adam Litke
2004-12-15 19:03 ` Anticipatory prefaulting in the page fault handler V3 Christoph Lameter
2005-01-05 0:29 ` Anticipatory prefaulting in the page fault handler V4 Christoph Lameter
2004-12-14 12:24 ` Anticipatory prefaulting in the page fault handler V1 Akinobu Mita
2004-12-14 15:25 ` Akinobu Mita
2004-12-14 20:25 ` Christoph Lameter
2004-12-09 10:57 ` Pavel Machek
2004-12-09 11:32 ` Nick Piggin
2004-12-09 17:05 ` Christoph Lameter
2004-12-14 15:28 ` Adam Litke
2004-12-02 18:43 ` page fault scalability patch V12 [0/7]: Overview and performance tests cliff white
2004-12-06 19:33 ` Marcelo Tosatti
2004-12-02 16:24 ` Gerrit Huizenga
2004-12-02 17:34 ` cliff white
2004-12-02 19:48 ` Diego Calleja
2004-12-02 20:12 ` Jeff Garzik
2004-12-02 20:30 ` Diego Calleja
2004-12-02 21:08 ` Wichert Akkerman
2004-12-03 0:07 ` Francois Romieu
2004-12-02 7:00 ` Jeff Garzik
2004-12-02 7:05 ` Benjamin Herrenschmidt
2004-12-02 7:11 ` Jeff Garzik
2004-12-02 11:16 ` Benjamin Herrenschmidt
2004-12-02 14:30 ` Andy Warner
2005-01-06 23:40 ` Jeff Garzik
2004-12-02 18:27 ` Grant Grundler
2004-12-02 18:33 ` Andrew Morton
2004-12-02 18:36 ` Christoph Hellwig
2004-12-07 10:51 ` Pavel Machek
2004-12-09 8:00 ` Nick Piggin
2004-12-09 17:03 ` Christoph Lameter
2004-12-10 4:30 ` Nick Piggin
2004-12-09 18:37 ` Hugh Dickins
2004-12-09 22:02 ` page fault scalability patch V12: rss tasklist vs sloppy rss Christoph Lameter
2004-12-09 22:52 ` Andrew Morton
2004-12-09 22:52 ` William Lee Irwin III
2004-12-09 23:07 ` Christoph Lameter
2004-12-09 23:29 ` William Lee Irwin III
2004-12-09 23:49 ` Christoph Lameter
2004-12-10 4:26 ` page fault scalability patch V12 [0/7]: Overview and performance tests Nick Piggin
2004-12-10 4:54 ` Nick Piggin
2004-12-10 5:06 ` Benjamin Herrenschmidt
2004-12-10 5:19 ` Nick Piggin
2004-12-10 12:30 ` Hugh Dickins
2004-12-10 18:43 ` Christoph Lameter
2004-12-10 21:43 ` Hugh Dickins
2004-12-10 22:12 ` Andrew Morton
2004-12-10 23:52 ` Hugh Dickins
2004-12-11 0:18 ` Andrew Morton
2004-12-11 0:44 ` Hugh Dickins
2004-12-11 0:57 ` Andrew Morton
2004-12-11 9:23 ` Hugh Dickins
2004-12-12 7:54 ` Nick Piggin
2004-12-12 9:33 ` Hugh Dickins
2004-12-12 9:48 ` Nick Piggin
2004-12-12 21:24 ` William Lee Irwin III
2004-12-17 3:31 ` Christoph Lameter
2004-12-17 3:32 ` page fault scalability patch V13 [0/8]: Overview Christoph Lameter
2004-12-17 3:33 ` page fault scalability patch V13 [1/8]: Reduce the use of the page_table_lock Christoph Lameter
2004-12-17 3:33 ` page fault scalability patch V13 [2/8]: ia64 atomic pte operations Christoph Lameter
2004-12-17 3:34 ` page fault scalability patch V13 [3/8]: universal cmpxchg for i386 Christoph Lameter
2004-12-17 3:35 ` page fault scalability patch V13 [4/8]: atomic pte operations " Christoph Lameter
2004-12-17 3:36 ` page fault scalability patch V13 [5/8]: atomic pte operations for AMD64 Christoph Lameter
2004-12-17 3:38 ` page fault scalability patch V13 [7/8]: Split RSS Christoph Lameter
2004-12-17 3:39 ` page fault scalability patch V13 [8/8]: Prefaulting using ptep_cmpxchg Christoph Lameter
2004-12-17 5:55 ` page fault scalability patch V13 [0/8]: Overview Christoph Lameter
2004-12-10 20:03 ` pfault V12 : correction to tasklist rss Christoph Lameter
2004-12-10 21:24 ` Hugh Dickins
2004-12-10 21:38 ` Andrew Morton
2004-12-11 6:03 ` William Lee Irwin III
2004-11-22 22:32 ` deferred rss update instead of sloppy rss Nick Piggin
2004-11-22 22:39 ` Christoph Lameter
2004-11-22 23:14 ` Nick Piggin
2004-11-19 19:44 ` page fault scalability patch V11 [2/7]: page fault handler optimizations Christoph Lameter
2004-11-19 19:44 ` page fault scalability patch V11 [3/7]: ia64 atomic pte operations Christoph Lameter
2004-11-19 19:45 ` page fault scalability patch V11 [4/7]: universal cmpxchg for i386 Christoph Lameter
2004-11-19 19:46 ` page fault scalability patch V11 [5/7]: i386 atomic pte operations Christoph Lameter
2004-11-19 19:46 ` page fault scalability patch V11 [6/7]: x86_64 " Christoph Lameter
2004-11-19 19:47 ` page fault scalability patch V11 [7/7]: s390 " Christoph Lameter
2004-11-19 19:59 ` page fault scalability patch V11 [0/7]: overview Linus Torvalds
2004-11-20 1:07 ` Nick Piggin
2004-11-20 1:29 ` Christoph Lameter
2004-11-20 1:45 ` Nick Piggin
2004-11-20 1:58 ` Linus Torvalds
2004-11-20 2:06 ` Linus Torvalds
2004-11-20 1:56 ` Linus Torvalds
2004-11-22 18:06 ` Bill Davidsen
2004-11-20 2:03 ` William Lee Irwin III
2004-11-20 2:25 ` Nick Piggin
2004-11-20 2:41 ` William Lee Irwin III
2004-11-20 2:46 ` Nick Piggin
2004-11-20 3:37 ` Nick Piggin
2004-11-20 3:55 ` William Lee Irwin III
2004-11-20 4:03 ` Nick Piggin
2004-11-20 4:06 ` Nick Piggin
2004-11-20 4:23 ` William Lee Irwin III
2004-11-20 4:29 ` Nick Piggin
2004-11-20 5:38 ` William Lee Irwin III
2004-11-20 5:50 ` Nick Piggin
2004-11-20 6:23 ` William Lee Irwin III
2004-11-20 6:49 ` Nick Piggin
2004-11-20 6:57 ` Andrew Morton
2004-11-20 7:04 ` Andrew Morton
2004-11-20 7:13 ` Nick Piggin
2004-11-20 8:00 ` William Lee Irwin III
2004-11-20 16:59 ` Martin J. Bligh
2004-11-20 17:14 ` Linus Torvalds
2004-11-20 19:08 ` William Lee Irwin III
2004-11-20 19:16 ` Linus Torvalds
2004-11-20 19:33 ` William Lee Irwin III
2004-11-22 17:44 ` Christoph Lameter
2004-11-22 22:43 ` William Lee Irwin III
2004-11-22 22:51 ` Christoph Lameter
2004-11-23 2:25 ` William Lee Irwin III
2004-11-20 20:25 ` [OT] " Adam Heath
2004-11-20 7:15 ` William Lee Irwin III
2004-11-20 7:29 ` Nick Piggin
2004-11-20 7:45 ` touch_nmi_watchdog (was: page fault scalability patch V11 [0/7]: overview) Nick Piggin
2004-11-20 7:57 ` page fault scalability patch V11 [0/7]: overview Nick Piggin
2004-11-20 8:25 ` William Lee Irwin III
2004-11-20 2:04 ` William Lee Irwin III
2004-11-20 2:18 ` Nick Piggin
2004-11-20 2:34 ` William Lee Irwin III
2004-11-20 2:40 ` Nick Piggin
2004-11-20 3:04 ` William Lee Irwin III
2004-11-20 3:14 ` Nick Piggin
2004-11-20 3:43 ` William Lee Irwin III
2004-11-20 3:58 ` Nick Piggin
2004-11-20 4:01 ` William Lee Irwin III
2004-11-20 4:34 ` Robin Holt
2004-11-20 3:33 ` Robin Holt
2004-11-20 4:24 ` William Lee Irwin III
2004-11-20 2:06 ` Robin Holt
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