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* [RFC][PATCH 0/5] Lockless vma lookups
@ 2007-03-06  1:38 Peter Zijlstra
  2007-03-06  1:38 ` [RFC][PATCH 1/5] RCU friendly B+tree Peter Zijlstra
                   ` (4 more replies)
  0 siblings, 5 replies; 11+ messages in thread
From: Peter Zijlstra @ 2007-03-06  1:38 UTC (permalink / raw)
  To: linux-mm
  Cc: Christoph Lameter, Paul E. McKenney, Nick Piggin, Ingo Molnar,
	Peter Zijlstra

mmap_sem is a scalability problem on LargeSMP due to cacheline bouncing
and -rt due to is RW nature.

The following (rough) patches implement an alternative approach to handling
vmas.

The RB-tree is discarted in favour of an B+tree like structure because RB-tree
rotations are RCU unfriendly and the in-place nodes as used don't help.

This allows for RCU lookups of vmas, furthermore they are pinned using a 
reference count. Modifiers of the vma structure will have to wait till it
drops.

The code as presented is nowhere near done; but it boots to a full KDE desktop
on my i386-up laptop and reached user-space and compiles a kernel on 
x86_64-smp (its having trouble starting a fancy X desktop though).

I'm posting this as a request for comments on the general direction.

Post early, avoid isolation, blabla ;-)

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^ permalink raw reply	[flat|nested] 11+ messages in thread

end of thread, other threads:[~2007-03-08 17:31 UTC | newest]

Thread overview: 11+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2007-03-06  1:38 [RFC][PATCH 0/5] Lockless vma lookups Peter Zijlstra
2007-03-06  1:38 ` [RFC][PATCH 1/5] RCU friendly B+tree Peter Zijlstra
2007-03-06  1:38 ` [RFC][PATCH 2/5] mm: use B+tree for vmas Peter Zijlstra
2007-03-06  1:38 ` [RFC][PATCH 3/5] mm: RCUify vma lookup Peter Zijlstra
2007-03-06  2:23   ` Nick Piggin
2007-03-06  8:36     ` Nick Piggin
2007-03-08 17:31       ` Ingo Molnar
2007-03-06 12:31     ` Peter Zijlstra
2007-03-06 12:35       ` Peter Zijlstra
2007-03-06  1:38 ` [RFC][PATCH 4/5] i386: lockless fault handler Peter Zijlstra
2007-03-06  1:38 ` [RFC][PATCH 5/5] x86_64: " Peter Zijlstra

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