Re: percpu-2.5.63-bkcurr

From: William Lee Irwin III (wli@holomorphy.com)
Date: Sat Mar 01 2003 - 02:36:55 EST

On Fri, Feb 28, 2003 at 09:59:22PM -0800, William Lee Irwin III wrote:
> Shove per-cpu areas into node-local memory for i386 discontigmem,
> or at least NUMA-Q. You'll have to plop down early_cpu_to_node()
> and early_node_to_cpumask() stubs to use it on, say Summit.

Tentative followup #1 (thanks Zwane!)

Use per-cpu rq's in the sched.c to avoid remote cache misses there.
It actually means something now.

Index: linux-2.5.59/kernel/sched.c
===================================================================
RCS file: /build/cvsroot/linux-2.5.59/kernel/sched.c,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 sched.c
--- linux-2.5.59/kernel/sched.c 17 Jan 2003 02:46:29 -0000 1.1.1.1
+++ linux-2.5.59/kernel/sched.c 17 Jan 2003 10:03:31 -0000
@@ -160,9 +160,9 @@
         atomic_t nr_iowait;
 } ____cacheline_aligned;
 
-static struct runqueue runqueues[NR_CPUS] __cacheline_aligned;
+static DEFINE_PER_CPU(struct runqueue, runqueues) = {{ 0 }};
 
-#define cpu_rq(cpu) (runqueues + (cpu))
+#define cpu_rq(cpu) (&per_cpu(runqueues, cpu))
 #define this_rq() cpu_rq(smp_processor_id())
 #define task_rq(p) cpu_rq(task_cpu(p))
 #define cpu_curr(cpu) (cpu_rq(cpu)->curr) 

-- 
function.linuxpower.ca
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