From bdf977b37418cdf8a2252504779a7e12a09b7575 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 3 Aug 2009 14:12:19 +0900 Subject: x86, percpu: Collect hot percpu variables into one cacheline On x86_64, percpu variables current_task and kernel_stack are used for get_current() and current_thread_info() respectively and thus are often used close to each other. Move definition of current_task to kernel/cpu/common.c right above kernel_stack definition and align it to cacheline so that they always fall into the same cacheline. Two percpu variables defined there together - irq_stack_ptr and irq_count - are also pretty hot and will benefit from sharing the cacheline. For consistency, current_task definition for x86_32 is also moved to kernel/cpu/common.c. Putting current_task and kernel_stack into the same cacheline was suggested by Linus Torvalds. Signed-off-by: Tejun Heo Cc: Linus Torvalds Cc: Ingo Molnar Signed-off-by: H. Peter Anvin --- arch/x86/kernel/process_32.c | 3 --- 1 file changed, 3 deletions(-) (limited to 'arch/x86/kernel/process_32.c') diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index 59f4524984a..daa4107be3b 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -61,9 +61,6 @@ asmlinkage void ret_from_fork(void) __asm__("ret_from_fork"); -DEFINE_PER_CPU(struct task_struct *, current_task) = &init_task; -EXPORT_PER_CPU_SYMBOL(current_task); - /* * Return saved PC of a blocked thread. */ -- cgit v1.2.3