diff options
| author | Eric W. Biederman <[email protected]> | 2019-09-14 07:33:34 -0500 |
|---|---|---|
| committer | Ingo Molnar <[email protected]> | 2019-09-25 17:42:29 +0200 |
| commit | 3fbd7ee285b2bbc6eebd15a3c8786d9776a402a8 (patch) | |
| tree | a953a7cc7d724fe39e2c1bd2d218d3dd956c180f /include/linux | |
| parent | 42fd8baab31f53bed2952485fcf0e92f244c5e55 (diff) | |
tasks: Add a count of task RCU users
Add a count of the number of RCU users (currently 1) of the task
struct so that we can later add the scheduler case and get rid of the
very subtle task_rcu_dereference(), and just use rcu_dereference().
As suggested by Oleg have the count overlap rcu_head so that no
additional space in task_struct is required.
Inspired-by: Linus Torvalds <[email protected]>
Inspired-by: Oleg Nesterov <[email protected]>
Signed-off-by: Eric W. Biederman <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Chris Metcalf <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: Davidlohr Bueso <[email protected]>
Cc: Kirill Tkhai <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Paul E. McKenney <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Russell King - ARM Linux admin <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/sched.h | 5 | ||||
| -rw-r--r-- | include/linux/sched/task.h | 1 |
2 files changed, 5 insertions, 1 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index e2e91960d79f..8e43e54a02c7 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1147,7 +1147,10 @@ struct task_struct { struct tlbflush_unmap_batch tlb_ubc; - struct rcu_head rcu; + union { + refcount_t rcu_users; + struct rcu_head rcu; + }; /* Cache last used pipe for splice(): */ struct pipe_inode_info *splice_pipe; diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h index 3d90ed8f75f0..153a683646ac 100644 --- a/include/linux/sched/task.h +++ b/include/linux/sched/task.h @@ -120,6 +120,7 @@ static inline void put_task_struct(struct task_struct *t) } struct task_struct *task_rcu_dereference(struct task_struct **ptask); +void put_task_struct_rcu_user(struct task_struct *task); #ifdef CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT extern int arch_task_struct_size __read_mostly; |