diff options
| author | Paul E. McKenney <paul.mckenney@linaro.org> | 2012-08-02 17:43:50 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2012-09-23 07:43:55 -0700 |
| commit | 1331e7a1bbe1f11b19c4327ba0853bee2a606543 (patch) | |
| tree | 596d9ed379ef7e2c5d8cf1cc0ba56ade084548ec /kernel/rcutree.h | |
| parent | a10d206ef1a83121ab7430cb196e0376a7145b22 (diff) | |
| download | blackbird-op-linux-1331e7a1bbe1f11b19c4327ba0853bee2a606543.tar.gz blackbird-op-linux-1331e7a1bbe1f11b19c4327ba0853bee2a606543.zip | |
rcu: Remove _rcu_barrier() dependency on __stop_machine()
Currently, _rcu_barrier() relies on preempt_disable() to prevent
any CPU from going offline, which in turn depends on CPU hotplug's
use of __stop_machine().
This patch therefore makes _rcu_barrier() use get_online_cpus() to
block CPU-hotplug operations. This has the added benefit of removing
the need for _rcu_barrier() to adopt callbacks: Because CPU-hotplug
operations are excluded, there can be no callbacks to adopt. This
commit simplifies the code accordingly.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Diffstat (limited to 'kernel/rcutree.h')
| -rw-r--r-- | kernel/rcutree.h | 3 |
1 files changed, 0 insertions, 3 deletions
diff --git a/kernel/rcutree.h b/kernel/rcutree.h index 4d29169f2124..94dfdf1f31f5 100644 --- a/kernel/rcutree.h +++ b/kernel/rcutree.h @@ -398,9 +398,6 @@ struct rcu_state { struct rcu_head **orphan_donetail; /* Tail of above. */ long qlen_lazy; /* Number of lazy callbacks. */ long qlen; /* Total number of callbacks. */ - struct task_struct *rcu_barrier_in_progress; - /* Task doing rcu_barrier(), */ - /* or NULL if no barrier. */ struct mutex barrier_mutex; /* Guards barrier fields. */ atomic_t barrier_cpu_count; /* # CPUs waiting on. */ struct completion barrier_completion; /* Wake at barrier end. */ |
