2.6.27-stable review patch. If anyone has any objections, please let us know. ------------------ From: Ravikiran G Thirumalai commit 26799a63110dcbe81291ea53178f6b4810d07424 upstream. 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 Acked-by: Mike Travis Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/head64.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -26,7 +26,7 @@ #include /* boot cpu pda */ -static struct x8664_pda _boot_cpu_pda __read_mostly; +static struct x8664_pda _boot_cpu_pda; #ifdef CONFIG_SMP /* -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/