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authorRavikiran G Thirumalai <kiran@scalex86.org>2008-12-31 13:44:46 -0800
committerIngo Molnar <mingo@elte.hu>2009-01-02 17:16:29 +0100
commit26799a63110dcbe81291ea53178f6b4810d07424 (patch)
tree0bdbd0ff3ed50b310d3851f8ab203e7b9c8c4a3c /arch/x86
parentb58602a4bac012b5f4fc12fe6b46ab237b610d5d (diff)
downloadblackbird-op-linux-26799a63110dcbe81291ea53178f6b4810d07424.tar.gz
blackbird-op-linux-26799a63110dcbe81291ea53178f6b4810d07424.zip
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>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kernel/head64.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index 388e05a5fc17..b9a4d8c4b935 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -27,7 +27,7 @@
#include <asm/trampoline.h>
/* boot cpu pda */
-static struct x8664_pda _boot_cpu_pda __read_mostly;
+static struct x8664_pda _boot_cpu_pda;
#ifdef CONFIG_SMP
/*
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