From 6c9ae009b298753a3baf71298d676a68b5a10c8f Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 13 Jan 2011 15:45:38 -0800 Subject: irq: use per_cpu kstat_irqs Use modern per_cpu API to increment {soft|hard}irq counters, and use per_cpu allocation for (struct irq_desc)->kstats_irq instead of an array. This gives better SMP/NUMA locality and saves few instructions per irq. With small nr_cpuids values (8 for example), kstats_irq was a small array (less than L1_CACHE_BYTES), potentially source of false sharing. In the !CONFIG_SPARSE_IRQ case, remove the huge, NUMA/cache unfriendly kstat_irqs_all[NR_IRQS][NR_CPUS] array. Note: we still populate kstats_irq for all possible irqs in early_irq_init(). We probably could use on-demand allocations. (Code included in alloc_descs()). Problem is not all IRQS are used with a prior alloc_descs() call. kstat_irqs_this_cpu() is not used anymore, remove it. Signed-off-by: Eric Dumazet Reviewed-by: Christoph Lameter Cc: Ingo Molnar Cc: Andi Kleen Cc: Tejun Heo Cc: Thomas Gleixner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/irqdesc.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/irqdesc.h') diff --git a/include/linux/irqdesc.h b/include/linux/irqdesc.h index 979c68cc7458..6a64c6fa81af 100644 --- a/include/linux/irqdesc.h +++ b/include/linux/irqdesc.h @@ -57,7 +57,7 @@ struct irq_desc { #endif struct timer_rand_state *timer_rand_state; - unsigned int *kstat_irqs; + unsigned int __percpu *kstat_irqs; irq_flow_handler_t handle_irq; struct irqaction *action; /* IRQ action list */ unsigned int status; /* IRQ status */ -- cgit v1.2.3