From cca6f3931920a7547d02e68adc2ca635bea5600c Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Tue, 8 May 2012 21:00:28 -0700 Subject: [PATCH] rcu: Size rcu_node tree from nr_cpu_ids rather than NR_CPUS The rcu_node tree array is sized based on compile-time constants, including NR_CPUS. Although this approach has worked well in the past, the recent trend by many distros to define NR_CPUS=4096 results in excessive grace-period-initialization latencies. This commit therefore substitutes the run-time computed nr_cpu_ids for the compile-time NR_CPUS when building the tree. This can result in much of the compile-time-allocated rcu_node array being unused. If this is a major problem, you are in a specialized situation anyway, so you can manually adjust the NR_CPUS, RCU_FANOUT, and RCU_FANOUT_LEAF kernel config parameters. Signed-off-by: Paul E. McKenney --- Reading git-format-patch failed