Re: [patch 4/4] ipc: sem optimise simple operations

[Manfred Spraul <manfred@colorfullife.com>]

On 08/11/2009 01:09 PM, npiggin@suse.de wrote:
> @@ -438,23 +448,94 @@ again:
>   			continue;
>
>   		list_del(&q->list);
> +		if (q->nsops == 1)
> +			list_del(&q->simple_list);
> +		else
> +			sma->complex_count--;
> +
> +		alter = q->alter;
> +		wake_up_sem_queue(q, error);
>    
Unlink approach one: list_del() only if q->nsops!=1.

@@ -532,6 +613,9 @@ static void freeary(struct ipc_namespace
>   	/* Wake up all pending processes and let them fail with EIDRM. */
>   	list_for_each_entry_safe(q, tq,&sma->sem_pending, list) {
>   		list_del(&q->list);
> +		list_del(&q->simple_list);
> +		if (q->nsops>  1)
> +			sma->complex_count--;
>    
Unlink approach two: list_del() even if q->nsops==1.
[i.e.: rely on list_del() on an empty list is permitted].

I would merge that into a helper function.

--
     Manfred