From 58e9934fe305f5c2caeb252cfc478c9111841d6f Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 1 Dec 2009 12:21:47 +0100 Subject: [PATCH] sched: Remove unnecessary RCU exclusion commit fb58bac5c75bfff8bbf7d02071a10a62f32fe28b upstream As Nick pointed out, and realized by myself when doing: sched: Fix balance vs hotplug race the patch: sched: for_each_domain() vs RCU is wrong, sched_domains are freed after synchronize_sched(), which means disabling preemption is enough. Reported-by: Nick Piggin Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar Signed-off-by: Mike Galbraith Signed-off-by: Greg Kroah-Hartman --- kernel/sched_fair.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index be3450816f9e..d2c46e761fcd 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1410,7 +1410,6 @@ select_task_rq_fair(struct rq *rq, struct task_struct *p, int sd_flag, int wake_ new_cpu = prev_cpu; } - rcu_read_lock(); for_each_domain(cpu, tmp) { if (!(tmp->flags & SD_LOAD_BALANCE)) continue; @@ -1500,10 +1499,8 @@ select_task_rq_fair(struct rq *rq, struct task_struct *p, int sd_flag, int wake_ } } - if (affine_sd && wake_affine(affine_sd, p, sync)) { - new_cpu = cpu; - goto out; - } + if (affine_sd && wake_affine(affine_sd, p, sync)) + return cpu; while (sd) { int load_idx = sd->forkexec_idx; @@ -1544,8 +1541,6 @@ select_task_rq_fair(struct rq *rq, struct task_struct *p, int sd_flag, int wake_ /* while loop will break here if sd == NULL */ } -out: - rcu_read_unlock(); return new_cpu; } #endif /* CONFIG_SMP */ -- 2.34.1