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| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2009-08-27 14:58:16 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-08-29 15:34:39 +0200 |
| commit | dd5d19bafd90d33043a4a14b2e2d98612caa293c (patch) | |
| tree | c21d547124d277f00332bdb01c75f2f4f321de8c /include/linux | |
| parent | 06e799764eb7c2e4640888d438c3524d756613e1 (diff) | |
| download | linux-dd5d19bafd90d33043a4a14b2e2d98612caa293c.tar.gz linux-dd5d19bafd90d33043a4a14b2e2d98612caa293c.tar.bz2 linux-dd5d19bafd90d33043a4a14b2e2d98612caa293c.zip | |
rcu: Create rcutree plugins to handle hotplug CPU for multi-level trees
When offlining CPUs from a multi-level tree, there is the
possibility of offlining the last CPU from a given node when
there are preempted RCU read-side critical sections that
started life on one of the CPUs on that node.
In this case, the corresponding tasks will be enqueued via the
task_struct's rcu_node_entry list_head onto one of the
rcu_node's blocked_tasks[] lists. These tasks need to be moved
somewhere else so that they will prevent the current grace
period from ending. That somewhere is the root rcu_node.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: akpm@linux-foundation.org
Cc: mathieu.desnoyers@polymtl.ca
Cc: josht@linux.vnet.ibm.com
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
LKML-Reference: <20090827215816.GA30472@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/init_task.h | 2 | ||||
| -rw-r--r-- | include/linux/sched.h | 4 |
2 files changed, 3 insertions, 3 deletions
diff --git a/include/linux/init_task.h b/include/linux/init_task.h index 79d4baee31b6..9e7f2e8fc66e 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -98,7 +98,7 @@ extern struct group_info init_groups; #define INIT_TASK_RCU_PREEMPT(tsk) \ .rcu_read_lock_nesting = 0, \ .rcu_read_unlock_special = 0, \ - .rcu_blocked_cpu = -1, \ + .rcu_blocked_node = NULL, \ .rcu_node_entry = LIST_HEAD_INIT(tsk.rcu_node_entry), #else #define INIT_TASK_RCU_PREEMPT(tsk) diff --git a/include/linux/sched.h b/include/linux/sched.h index bfca26d63b13..3fe03151a8e6 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1208,7 +1208,7 @@ struct task_struct { #ifdef CONFIG_TREE_PREEMPT_RCU int rcu_read_lock_nesting; char rcu_read_unlock_special; - int rcu_blocked_cpu; + void *rcu_blocked_node; struct list_head rcu_node_entry; #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */ @@ -1735,7 +1735,7 @@ static inline void rcu_copy_process(struct task_struct *p) { p->rcu_read_lock_nesting = 0; p->rcu_read_unlock_special = 0; - p->rcu_blocked_cpu = -1; + p->rcu_blocked_node = NULL; INIT_LIST_HEAD(&p->rcu_node_entry); } |