x86: fix incorrect __read_mostly on _boot_cpu_pda
authorRavikiran G Thirumalai <kiran@scalex86.org>
Wed, 31 Dec 2008 21:44:46 +0000 (13:44 -0800)
committerIngo Molnar <mingo@elte.hu>
Fri, 2 Jan 2009 16:16:29 +0000 (17:16 +0100)
commit26799a63110dcbe81291ea53178f6b4810d07424
tree0bdbd0ff3ed50b310d3851f8ab203e7b9c8c4a3c
parentb58602a4bac012b5f4fc12fe6b46ab237b610d5d
x86: fix incorrect __read_mostly on _boot_cpu_pda

The pda rework (commit 3461b0af025251bbc6b3d56c821c6ac2de6f7209)
to remove static boot cpu pdas introduced a performance bug.

_boot_cpu_pda is the actual pda used by the boot cpu and is definitely
not "__read_mostly" and ended up polluting the read mostly section with
writes.  This bug caused regression of about 8-10% on certain syscall
intensive workloads.

Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org>
Acked-by: Mike Travis <travis@sgi.com>
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
arch/x86/kernel/head64.c