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Date: Mon, 3 Jun 2024 04:36:31 +0100
From: Matthew Wilcox <willy@infradead.org>
To: Lance Yang <ioworker0@gmail.com>
Cc: akpm@linux-foundation.org, ryan.roberts@arm.com, david@redhat.com,
	21cnbao@gmail.com, baolin.wang@linux.alibaba.com, ziy@nvidia.com,
	fengwei.yin@intel.com, ying.huang@intel.com, libang.li@antgroup.com,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/1] mm/mlock: implement folio_mlock_step() using
 folio_pte_batch()
Message-ID: <Zl06P-qdpca2V9aJ@casper.infradead.org>
References: <20240603033118.76457-1-ioworker0@gmail.com>
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On Mon, Jun 03, 2024 at 11:31:17AM +0800, Lance Yang wrote:
>  {
> -	unsigned int count, i, nr = folio_nr_pages(folio);
> -	unsigned long pfn = folio_pfn(folio);
> -	pte_t ptent = ptep_get(pte);

Please don't move type declarations later in the function.  Just because
you can doesn't mean you should.

> -	if (!folio_test_large(folio))
> +	if (likely(!folio_test_large(folio)))
>  		return 1;

How likely is this now?  How likely will it be in two years time?
Does this actually make any difference in either code generation or
performance?