Re: [PATCH] rbtree: stop iteration early in rb_find_first

From: Peter Zijlstra <peterz@infradead.org>
To: Li RongQing <lirongqing@baidu.com>
Cc: dbueso@suse.de, mingo@kernel.org, michel@lespinasse.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] rbtree: stop iteration early in rb_find_first
Date: Wed, 25 Aug 2021 13:39:26 +0200	[thread overview]
Message-ID: <YSYr7nqql825rHol@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <1629885588-10590-1-git-send-email-lirongqing@baidu.com>

On Wed, Aug 25, 2021 at 05:59:48PM +0800, Li RongQing wrote:
> stop iteration if match is not NULL and result of cmp is
> not zero, this means the matched node has been found, and
> the node with same key has been passed
> 
> Signed-off-by: Li RongQing <lirongqing@baidu.com>
> ---
>  include/linux/rbtree.h | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/include/linux/rbtree.h b/include/linux/rbtree.h
> index d31ecaf4fdd3..2689771df9bb 100644
> --- a/include/linux/rbtree.h
> +++ b/include/linux/rbtree.h
> @@ -324,6 +324,9 @@ rb_find_first(const void *key, const struct rb_root *tree,
>  		} else if (c > 0) {
>  			node = node->rb_right;
>  		}
> +
> +		if (match && c)
> +			break;
>  	}
>  
>  	return match;

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>