From: Ingo Molnar Date: Mon, 19 Feb 2007 18:11:56 +0000 (+0000) Subject: [PATCH] NOHZ: Fix RCU handling X-Git-Tag: v2.6.21-rc1~62 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6ba9b346e1e0eca65ec589d32de3a9fe32dc5de6;p=linux-2.6 [PATCH] NOHZ: Fix RCU handling When a CPU is needed for RCU the tick has to continue even when it was stopped before. Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner Signed-off-by: Linus Torvalds --- diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 95e41f7f85..9234e44fc9 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -191,19 +191,19 @@ void tick_nohz_stop_sched_tick(void) next_jiffies = get_next_timer_interrupt(last_jiffies); delta_jiffies = next_jiffies - last_jiffies; + if (rcu_needs_cpu(cpu)) + delta_jiffies = 1; /* * Do not stop the tick, if we are only one off * or if the cpu is required for rcu */ - if (!ts->tick_stopped && (delta_jiffies == 1 || rcu_needs_cpu(cpu))) + if (!ts->tick_stopped && delta_jiffies == 1) goto out; /* Schedule the tick, if we are at least one jiffie off */ if ((long)delta_jiffies >= 1) { - if (rcu_needs_cpu(cpu)) - delta_jiffies = 1; - else + if (delta_jiffies > 1) cpu_set(cpu, nohz_cpu_mask); /* * nohz_stop_sched_tick can be called several times before