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rcu: Fix comparison sense in rcu_needs_cpu() 

Commit c0f4dfd4f (rcu: Make RCU_FAST_NO_HZ take advantage of numbered
callbacks) introduced a bug that can result in excessively long grace
periods.  This bug reverse the senes of the "if" statement checking
for lazy callbacks, so that RCU takes a lazy approach when there are
in fact non-lazy callbacks.  This can result in excessive boot, suspend,
and resume times.

This commit therefore fixes the sense of this "if" statement.

Reported-by: Borislav Petkov <bp@alien8.de>
Reported-by: Bjørn Mork <bjorn@mork.no>
Reported-by: Joerg Roedel <joro@8bytes.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Bjørn Mork <bjorn@mork.no>
Tested-by: Joerg Roedel <joro@8bytes.org>
This commit is contained in:
Paul E. McKenney 2013-05-13 06:53:37 -07:00
parent f722406faa
commit 6faf72834d
1 changed files with 1 additions and 1 deletions
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2
kernel/rcutree_plugin.h
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@ -1667,7 +1667,7 @@ int rcu_needs_cpu(int cpu, unsigned long *dj)
rdtp->last_accelerate = jiffies;
/* Request timer delay depending on laziness, and round. */
if (rdtp->all_lazy) {
if (!rdtp->all_lazy) {
*dj = round_up(rcu_idle_gp_delay + jiffies,
rcu_idle_gp_delay) - jiffies;
} else {