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
Date: Fri, 25 Jul 2025 16:45:31 +0100 [thread overview]
Message-ID: <aIOmm8cejmAyvSZ5@casper.infradead.org> (raw)
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.
next prev parent reply other threads:[~2025-07-25 15:45 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-07-25 15:28 Xiaole He
2025-07-25 15:45 ` Matthew Wilcox [this message]
2025-07-25 23:24 ` Xiaole He
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