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

From: Xie XiuQi
Date: Sun Sep 08 2013 - 22:08:46 EST


On 2013/9/8 23:22, Jiang Liu wrote:
> From: Jiang Liu <jiang.liu@xxxxxxxxxx>
>
> 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@xxxxxxxxxx>
> Cc: Jiang Liu <liuj97@xxxxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: Wang YanQing <udknight@xxxxxxxxx>
> Cc: Shaohua Li <shli@xxxxxxxxxx>
> Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxx>
> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
> Cc: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>
> Cc: liguang <lig.fnst@xxxxxxxxxxxxxx>
> Cc: linux-kernel@xxxxxxxxxxxxxxx

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);
> }
> }
>
>


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