Messages in this thread | | | Subject | Re: [PATCH 6/7] sched, x86: Provide a per-cpu preempt_count implementation | From | Eric Dumazet <> | Date | Tue, 10 Sep 2013 07:02:51 -0700 |
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On Tue, 2013-09-10 at 15:08 +0200, Peter Zijlstra wrote:
> +static __always_inline int preempt_count(void) > +{ > + return __this_cpu_read_4(__preempt_count) & ~PREEMPT_NEED_RESCHED; > +}
Not sure why you used the _4 prefix on all accessors ?
> > +#ifdef CONFIG_PREEMPT_COUNT > + /* > + * If it were not for PREEMPT_ACTIVE we could guarantee that the > + * preempt_count of all tasks was equal here and this would not be > + * needed. > + */ > + task_thread_info(prev_p)->saved_preempt_count = __raw_get_cpu_var(__preempt_count);
this_cpu_read(__preempt_count) ?
> + __raw_get_cpu_var(__preempt_count) = task_thread_info(next_p)->saved_preempt_count;
this_cpu_write(__preempt_count, task_thread_info(next_p)->saved_preempt_count;
> +#endif > + > this_cpu_write(kernel_stack, > (unsigned long)task_stack_page(next_p) + > THREAD_SIZE - KERNEL_STACK_OFFSET); > >
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