Messages in this thread | | | Date | Wed, 31 Dec 2008 14:18:17 -0800 | From | Mike Travis <> | Subject | Re: [patch] x86: Fix incorrect __read_mostly on _boot_cpu_pda |
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Ravikiran G Thirumalai wrote: > The pda rework (commit 3461b0af025251bbc6b3d56c821c6ac2de6f7209) > to remove static boot cpu pdas introduced a 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> > > Index: linux-2.6/arch/x86/kernel/head64.c > =================================================================== > --- linux-2.6.orig/arch/x86/kernel/head64.c 2008-12-30 15:28:08.000000000 -0800 > +++ linux-2.6/arch/x86/kernel/head64.c 2008-12-31 10:36:21.000000000 -0800 > @@ -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 > /*
Thanks for catching that!
Mike
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