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author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2013-05-13 06:53:37 -0700 |
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committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2013-05-14 10:53:41 -0700 |
commit | 6faf72834d9d0c0dc6632604eaeffb621e87fcf9 (patch) | |
tree | f72dcd0bfd3b3a43852fd745d580faff6d520141 | |
parent | f722406faae2d073cc1d01063d1123c35425939e (diff) | |
download | op-kernel-dev-6faf72834d9d0c0dc6632604eaeffb621e87fcf9.zip op-kernel-dev-6faf72834d9d0c0dc6632604eaeffb621e87fcf9.tar.gz |
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>
-rw-r--r-- | kernel/rcutree_plugin.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h index 170814d..6d939a6 100644 --- a/kernel/rcutree_plugin.h +++ b/kernel/rcutree_plugin.h @@ -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 { |