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| author | Paul E. McKenney | 2012-01-06 23:11:30 +0100 |
|---|---|---|
| committer | Paul E. McKenney | 2012-02-21 18:03:25 +0100 |
| commit | 486e259340fc4c60474f2c14703e3b3634bb58ca (patch) | |
| tree | 70a58702194588fa0773463523f72c682785d040 /init | |
| parent | rcu: Add diagnostic for misaligned rcu_head structures (diff) | |
| download | kernel-qcow2-linux-486e259340fc4c60474f2c14703e3b3634bb58ca.tar.gz kernel-qcow2-linux-486e259340fc4c60474f2c14703e3b3634bb58ca.tar.xz kernel-qcow2-linux-486e259340fc4c60474f2c14703e3b3634bb58ca.zip | |
rcu: Avoid waking up CPUs having only kfree_rcu() callbacks
When CONFIG_RCU_FAST_NO_HZ is enabled, RCU will allow a given CPU to
enter dyntick-idle mode even if it still has RCU callbacks queued.
RCU avoids system hangs in this case by scheduling a timer for several
jiffies in the future. However, if all of the callbacks on that CPU
are from kfree_rcu(), there is no reason to wake the CPU up, as it is
not a problem to defer freeing of memory.
This commit therefore tracks the number of callbacks on a given CPU
that are from kfree_rcu(), and avoids scheduling the timer if all of
a given CPU's callbacks are from kfree_rcu().
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'init')
0 files changed, 0 insertions, 0 deletions