Re: [GIT PULL rcu/next] rcu commits for 2.6.40

[Yinghai Lu <yinghai@kernel.org>]

On Mon, May 9, 2011 at 12:36 AM, Ingo Molnar <mingo@elte.hu> wrote:
>
> * Paul E. McKenney <paulmck@linux.vnet.ibm.com> wrote:
>
>> Hello, Ingo,
>>
>> This pull request covers RCU chnages for 2.6.40.  The major new features
>> are RCU priority boosting and the addition of kfree_rcu(), the latter
>> courtesy of Lai Jiangshan.  These two features cover well over half
>> of the commits.  There are a number of smaller features and bug fixes.
>> All have been sent to LKML in the following batches:
>>
>> 0.    https://lkml.org/lkml/2011/2/22/660: RCU priority boosting preview
>> 1.    https://lkml.org/lkml/2011/5/1/19: RCU priority boosting, kfree_rcu()
>> 2.    https://lkml.org/lkml/2011/5/2/40: More uses of kfree_rcu()
>> 3.    https://lkml.org/lkml/2011/5/8/60: miscellaneous
>>
>> The kfree_rcu() uses in the pull request have Acked-by:s from the
>> maintainers.  I have some additional kfree_rcu() requests that lack
>> Acked-by:s, and I will deal with these later.
>>
>> These channges are available in the -rcu git repository at:
>>
>>   git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-2.6-rcu.git rcu/next
>
> Pulled, thanks a lot Paul!
>

it seems with this one in tip, my 8 sockets test setup will report cpu stall.

after hard code to enable rcu_cpu_stall_suppress

Index: linux-2.6/kernel/rcutree.c
===================================================================
--- linux-2.6.orig/kernel/rcutree.c
+++ linux-2.6/kernel/rcutree.c
@@ -174,7 +174,7 @@ module_param(blimit, int, 0);
 module_param(qhimark, int, 0);
 module_param(qlowmark, int, 0);

-int rcu_cpu_stall_suppress __read_mostly;
+int rcu_cpu_stall_suppress __read_mostly = 1;
 module_param(rcu_cpu_stall_suppress, int, 0644);

 static void force_quiescent_state(struct rcu_state *rsp, int relaxed);

will get system hang after pnp ACPI init.

Thanks

Yinghai