From: Christoph Lameter <clameter@sgi.com>
To: linux-mm@kvack.org
Subject: ZERO_PAGE refcounting causes cache line bouncing
Date: Fri, 16 Mar 2007 15:17:39 -0700 (PDT) [thread overview]
Message-ID: <Pine.LNX.4.64.0703161514170.7846@schroedinger.engr.sgi.com> (raw)
We have issues with ZERO_PAGE refcounting causing severe cacheline
bouncing. ZERO_PAGES are mapped into multiple processes running on
multiple nodes. Refcounter modifications therefore have to acquire a
remote exclusive cacheline.
Could we somehow fix this? There are a couple of ways to do this:
1. No refcounting on reserved pages in the VM. ZERO_PAGEs are
reserved and there is no point in refcounting them since they
will not go away.
2. Having a percpu or pernode ZERO_PAGE?
May be a simpler solution but then we still may have issues
if the ZERO_PAGE gets "freed" from other processors/ nodes.
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next reply other threads:[~2007-03-16 22:17 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-03-16 22:17 Christoph Lameter [this message]
2007-03-17 4:35 ` William Lee Irwin III
2007-03-19 5:56 ` Nick Piggin
2007-03-19 6:24 ` Nick Piggin
2007-03-19 6:41 ` Nick Piggin
2007-03-19 10:04 ` Nick Piggin
2007-03-19 17:06 ` Christoph Lameter
2007-03-20 2:53 ` Nick Piggin
2007-03-19 12:03 ` Robin Holt
2007-03-20 2:35 ` Nick Piggin
2007-03-19 12:46 ` William Lee Irwin III
2007-03-20 2:34 ` Nick Piggin
2007-03-19 17:04 ` Christoph Lameter
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