Commit 622ea685 authored by Paul E. McKenney's avatar Paul E. McKenney Committed by Ingo Molnar

rcu: Fix holdoff for accelerated GPs for last non-dynticked CPU

Make the holdoff only happen when the full number of attempts
have been made.
Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1267311188-16603-1-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 71da8132
...@@ -1010,6 +1010,10 @@ int rcu_needs_cpu(int cpu) ...@@ -1010,6 +1010,10 @@ int rcu_needs_cpu(int cpu)
int c = 0; int c = 0;
int thatcpu; int thatcpu;
/* Check for being in the holdoff period. */
if (per_cpu(rcu_dyntick_holdoff, cpu) == jiffies)
return rcu_needs_cpu_quick_check(cpu);
/* Don't bother unless we are the last non-dyntick-idle CPU. */ /* Don't bother unless we are the last non-dyntick-idle CPU. */
for_each_cpu_not(thatcpu, nohz_cpu_mask) for_each_cpu_not(thatcpu, nohz_cpu_mask)
if (thatcpu != cpu) { if (thatcpu != cpu) {
...@@ -1041,10 +1045,8 @@ int rcu_needs_cpu(int cpu) ...@@ -1041,10 +1045,8 @@ int rcu_needs_cpu(int cpu)
} }
/* If RCU callbacks are still pending, RCU still needs this CPU. */ /* If RCU callbacks are still pending, RCU still needs this CPU. */
if (c) { if (c)
raise_softirq(RCU_SOFTIRQ); raise_softirq(RCU_SOFTIRQ);
per_cpu(rcu_dyntick_holdoff, cpu) = jiffies;
}
return c; return c;
} }
......
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