Re: [PATCH v1 2/3] SMP: simpilify function generic_smp_call_function_single_interrupt()

[Xie XiuQi <xiexiuqi@huawei.com>]

On 2013/9/8 23:22, Jiang Liu wrote:
> From: Jiang Liu <jiang.liu@huawei.com>
> 
> Now the call_single_data data structure is always locked by invoking
> csd_lock() before inserting it into corresponding call_single_queue
> list, so no need to save and check csd->flags in function
> generic_smp_call_function_single_interrupt().
> 
> Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
> Cc: Jiang Liu <liuj97@gmail.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Wang YanQing <udknight@gmail.com>
> Cc: Shaohua Li <shli@kernel.org>
> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
> Cc: Ingo Molnar <mingo@elte.hu>
> Cc: Steven Rostedt <rostedt@goodmis.org>
> Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
> Cc: liguang <lig.fnst@cn.fujitsu.com>
> Cc: linux-kernel@vger.kernel.org

Hi, I've sent a same patch before and it has been applied by Ingo.
See http://git.kernel.org/cgit/linux/kernel/git/tip/tip.git/commit/?id=46591962cb5bfd2bfb0baf42497119c816503598

> ---
>  kernel/smp.c | 16 +---------------
>  1 file changed, 1 insertion(+), 15 deletions(-)
> 
> diff --git a/kernel/smp.c b/kernel/smp.c
> index a034712..baa2a65 100644
> --- a/kernel/smp.c
> +++ b/kernel/smp.c
> @@ -181,25 +181,11 @@ void generic_smp_call_function_single_interrupt(void)
>  
>  	while (!list_empty(&list)) {
>  		struct call_single_data *csd;
> -		unsigned int csd_flags;
>  
>  		csd = list_entry(list.next, struct call_single_data, list);
>  		list_del(&csd->list);
> -
> -		/*
> -		 * 'csd' can be invalid after this call if flags == 0
> -		 * (when called through generic_exec_single()),
> -		 * so save them away before making the call:
> -		 */
> -		csd_flags = csd->flags;
> -
>  		csd->func(csd->info);
> -
> -		/*
> -		 * Unlocked CSDs are valid through generic_exec_single():
> -		 */
> -		if (csd_flags & CSD_FLAG_LOCK)
> -			csd_unlock(csd);
> +		csd_unlock(csd);
>  	}
>  }
>  
>