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| author | Paul E. McKenney <paul.mckenney@linaro.org> | 2012-05-04 08:31:53 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2012-06-06 20:43:27 -0700 |
| commit | 8f5af6f1f2d09fe5eac86a5dc1731a5917c1503a (patch) | |
| tree | b7093c8c08377f23645cc7d3619f3fc5c5bdf6f8 | |
| parent | f8f5701bdaf9134b1f90e5044a82c66324d2073f (diff) | |
| download | lwn-8f5af6f1f2d09fe5eac86a5dc1731a5917c1503a.tar.gz lwn-8f5af6f1f2d09fe5eac86a5dc1731a5917c1503a.zip | |
rcu: RCU_FAST_NO_HZ detection of callback adoption
In the present implementations of CPU hotplug, the outgoing CPU is
guaranteed to run its stop-machine process on the way out, which
will guarantee that RCU_FAST_NO_HZ forces the CPU out of dyntick-idle
mode.
However, new versions of CPU hotplug might not work this way. This
commit therefore removes this design constraint by explicitly notifying
CPUs when they adopt non-lazy RCU callbacks.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Tested-by: Pascal Chapperon <pascal.chapperon@wanadoo.fr>
| -rw-r--r-- | kernel/rcutree.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/rcutree.c b/kernel/rcutree.c index 0da7b88d92d0..3b0f1337f75b 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -1397,6 +1397,8 @@ static void rcu_adopt_orphan_cbs(struct rcu_state *rsp) rdp->qlen_lazy += rsp->qlen_lazy; rdp->qlen += rsp->qlen; rdp->n_cbs_adopted += rsp->qlen; + if (rsp->qlen_lazy != rsp->qlen) + rcu_idle_count_callbacks_posted(); rsp->qlen_lazy = 0; rsp->qlen = 0; |