2012/11/29 Li Zhong <zh...@linux.vnet.ibm.com>:
> On Tue, 2012-11-27 at 19:33 +0100, Frederic Weisbecker wrote:
> [....]
>> -
>> - WARN_ON_ONCE(!current->mm);
>> -
>> - local_irq_save(flags);
>> - rdtp = &__get_cpu_var(rcu_dynticks);
>> - if (!rdtp->ignore_user_qs && !rdtp->in_user) {
>> - rdtp->in_user = true;
>> - rcu_eqs_enter(true);
>> - }
>
> It seems to me that ignore_user_qs and in_user defined in struct
> rcu_dynticks are no longer needed?
>
> If so, then maybe we could remove them, code below:
>
> ==========
> diff --git a/kernel/rcutree.c b/kernel/rcutree.c
> index e441b77..b8fae5d 100644
> --- a/kernel/rcutree.c
> +++ b/kernel/rcutree.c
> @@ -2719,9 +2719,6 @@ rcu_boot_init_percpu_data(int cpu, struct rcu_state
> *rsp)
> rdp->dynticks = &per_cpu(rcu_dynticks, cpu);
> WARN_ON_ONCE(rdp->dynticks->dynticks_nesting !=
> DYNTICK_TASK_EXIT_IDLE);
> WARN_ON_ONCE(atomic_read(&rdp->dynticks->dynticks) != 1);
> -#ifdef CONFIG_RCU_USER_QS
> - WARN_ON_ONCE(rdp->dynticks->in_user);
> -#endif
> rdp->cpu = cpu;
> rdp->rsp = rsp;
> rcu_boot_init_nocb_percpu_data(rdp);
> diff --git a/kernel/rcutree.h b/kernel/rcutree.h
> index 4b69291..6f21f2e 100644
> --- a/kernel/rcutree.h
> +++ b/kernel/rcutree.h
> @@ -102,10 +102,6 @@ struct rcu_dynticks {
> /* idle-period nonlazy_posted snapshot. */
> int tick_nohz_enabled_snap; /* Previously seen value from sysfs. */
> #endif /* #ifdef CONFIG_RCU_FAST_NO_HZ */
> -#ifdef CONFIG_RCU_USER_QS
> - bool ignore_user_qs; /* Treat userspace as extended QS or not
> */
> - bool in_user; /* Is the CPU in userland from RCU POV? */
> -#endif
> };
>
> /* RCU's kthread states for tracing. */
>
>
Good point. Paul, do you prefer to fold these changes into my patch or
do we add a new one? In any case Li we need your Signed-off-by tag.
Thanks.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
