From: Hua Zhong <hzhong@gmail.com>
Date: Mon, 15 May 2006 16:44:22 +0000 (-0700)
Subject: [PATCH] fix can_share_swap_page() when !CONFIG_SWAP
X-Git-Tag: v2.6.17-rc5~133
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e6333fd4ddf7a583480017f535b9ea53c116ab81;p=pandora-kernel.git

[PATCH] fix can_share_swap_page() when !CONFIG_SWAP

can_share_swap_page() is used to check if the page has the last reference.
This avoids allocating a new page for COW if it's the last page.

However, if CONFIG_SWAP is not set, can_share_swap_page() is defined as 0,
thus always causes a copy for the last COW page.  The below simple patch
fixes it.

Signed-off-by: Hua Zhong <hzhong@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

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