Re: [RFC PATCH 4/5] RCU: Add TASK_RCU_OFFSET

[Lai Jiangshan <laijs@cn.fujitsu.com>]

On 04/07/2011 08:30 AM, Paul E. McKenney wrote:
> On Wed, Apr 06, 2011 at 02:27:39PM -0700, H. Peter Anvin wrote:
>> On 04/06/2011 02:06 PM, Peter Zijlstra wrote:
>>> On Wed, 2011-04-06 at 13:13 -0700, Paul E. McKenney wrote:
>>>> And the following patch builds correctly for defconfig x86 builds,
>>>> while allowing rcupdate.h to see the sched.h definitions as needed
>>>> to inline rcu_read_lock() and rcu_read_unlock().
>>>>
>>> Looks like an entirely reasonable patch to me ;-)
>>>
>>
>> Quite... a lot better than the original proposal!
> 
> Glad you both like it!
> 
> When I do an allyesconfig build, I do get errors during the "CHECK"
> phase, when it is putting things into the usr/include in the build tree.
> I believe that this is because I am exposing different header files to
> the library-export scripts.  The following patch silences some of them,
> but I am really out of my depth here.
> 
> Sam, Jan, Michal, help?
> 
> 							Thanx, Paul
> 
> ------------------------------------------------------------------------
> 

Easy to split rcupdate.h, hard to resolve the dependence problem.

You can apply the next additional patch when you test:

diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index 0b4496a..ccbebeb 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -788,4 +788,10 @@ static inline void debug_rcu_head_unqueue(struct rcu_head *head)
 #error "Unknown RCU implementation specified to kernel configuration"
 #endif
 
+#include <linux/sched.h>
+static inline long test_use_task_struct(void)
+{
+	return current->state;
+}
+
 #endif /* __LINUX_RCUPDATE_H */