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Date: Wed, 16 Feb 2005 16:57:47 -0800 (PST)
From: Christoph Lameter <clameter@sgi.com>
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To: torvalds@osdl.org, Andrew Morton <akpm@osdl.org>
cc: Nick Piggin <nickpiggin@yahoo.com.au>, Andi Kleen <ak@muc.de>,
       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 patchsets update: prezeroing, prefaulting
 and atomic operations
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I thought I save myself the constant crossposting of large amounts of
patches. Patches, documentation, test results etc are available at

http://oss.sgi.com/projects/page_fault_performance/

Changes:
- Performance tests for all patchsets (i386 single processor,
  Altix 8 processors and Altix 128 processors)
- Archives of patches so far
- Some docs (still needs work)
- Patches against 2.6.11-rc4-bk4

Patch specific:

atomic operations for page faults (V17)

- Avoid incrementing page count for page in do_wp_page (see discussion
  with Nick Piggin on last patchset)

prezeroing (V7)

- set /proc/sys/vm/scrub_load to 1 by default to avoid slight performance
  loss during kernel compile on i386
- Scrubd needs to be configured in kernel configuration as an experimental
  feature.
- Patch still follows kswapd's method to bind node specific scrubd daemons
  to each NUMA node. Cannot find any new infrastructure to assign tasks to
  certain nodes. kthread_bind() binds to single cpu and not to a NUMA
  node. Guess other API work would have to be first done to realize
  Andrews proposed approach.

prefaulting (V5)

- Set default for /proc/sys/vm/max_prealloc_order to 1 to avoid
  overallocating pages which led to a performance loss in some
  situations.

This is pretty complex thing to manage so please tell me if I missed
anything ...