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	Fri, 25 Jul 2025 15:45:32 +0000
Date: Fri, 25 Jul 2025 16:45:31 +0100
From: Matthew Wilcox <willy@infradead.org>
To: Xiaole He <hexiaole1994@126.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v1] mm/readahead: Optimize nr_to_read boundary check
Message-ID: <aIOmm8cejmAyvSZ5@casper.infradead.org>
References: <20250725152834.7602-1-hexiaole1994@126.com>
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In-Reply-To: <20250725152834.7602-1-hexiaole1994@126.com>

On Fri, Jul 25, 2025 at 11:28:34PM +0800, Xiaole He wrote:
> If nr_to_read is, for instance, 3, and end_index - index + 1 is also 3
> (meaning 3 pages remain), the condition 3 > 2 evaluates to true, leading
>  to nr_to_read being assigned 3 again. While compilers might optimize
> this trivial self-assignment, it introduces unnecessary logical overhead
>  and reduces code clarity.

But it makes the initial comparison more complex (by one operation) and
I bet you can't measure the difference anyway.  I'm not inclined to
tweak this.