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From: Matthew Wilcox <willy@infradead.org>
To: fujunjie <fujunjie1@qq.com>
Cc: Jan Kara <jack@suse.cz>,
	Andrew Morton <akpm@linux-foundation.org>,
	linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org,
	Roman Gushchin <roman.gushchin@linux.dev>,
	Haoran Zhu <zhr1502@sjtu.edu.cn>
Subject: Re: [PATCH v2 1/2] mm/filemap: count only the faulting address as a mmap hit
Date: Mon, 27 Apr 2026 19:40:19 +0100	[thread overview]
Message-ID: <ae-tkz6qe1zFmXVj@casper.infradead.org> (raw)
In-Reply-To: <tencent_949F3B157FE71D3C7247AE6FAE2C5AB82809@qq.com>

On Mon, Apr 27, 2026 at 04:57:50PM +0000, fujunjie wrote:
> -		/*
> -		 * If there are too many folios that are recently evicted
> -		 * in a file, they will probably continue to be evicted.
> -		 * In such situation, read-ahead is only a waste of IO.
> -		 * Don't decrease mmap_miss in this scenario to make sure
> -		 * we can stop read-ahead.
> -		 */

I'm sad to lose this comment.  Why not move it to ...

> +		ret |= map_ret;

here?

> +		if ((map_ret & VM_FAULT_NOPAGE) &&
> +		    !folio_test_workingset(folio)) {
> +			unsigned short mmap_miss;
> +
> +			mmap_miss = READ_ONCE(file->f_ra.mmap_miss);
> +			if (mmap_miss)
> +				WRITE_ONCE(file->f_ra.mmap_miss,
> +					   mmap_miss - 1);
> +		}


  reply	other threads:[~2026-04-27 18:40 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20260427165751.746502-1-fujunjie1@qq.com>
2026-04-27 16:57 ` [PATCH v2 1/2] mm/filemap: count only the faulting address as a mmap hit fujunjie
2026-04-27 18:40   ` Matthew Wilcox [this message]
2026-04-28  1:12     ` Fujunjie
2026-04-27 16:57 ` [PATCH v2 2/2] mm/filemap: do not count FAULT_FLAG_TRIED retries as mmap hits fujunjie

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