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From: "Kirill A. Shutemov" <kirill@shutemov.name>
To: Matthew Wilcox <willy@infradead.org>
Cc: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
	Hugh Dickins <hughd@google.com>
Subject: Re: [PATCH 1/2] mm: Remove redundant test from find_get_pages_contig
Date: Fri, 23 Nov 2018 13:47:32 +0300	[thread overview]
Message-ID: <20181123104732.gvhdqyddbsiq3i42@kshutemo-mobl1> (raw)
In-Reply-To: <20181122213224.12793-2-willy@infradead.org>

On Thu, Nov 22, 2018 at 01:32:23PM -0800, Matthew Wilcox wrote:
> After we establish a reference on the page, we check the pointer continues
> to be in the correct position in i_pages.  There's no need to check the
> page->mapping or page->index afterwards; if those can change after we've
> got the reference, they can change after we return the page to the caller.

Hm. IIRC, page->mapping can be set to NULL due truncation, but what about
index? When it can be changed? Truncation doesn't touch it.

-- 
 Kirill A. Shutemov

  reply	other threads:[~2018-11-23 10:47 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-22 21:32 [PATCH 0/2] Better support for THP in page cache Matthew Wilcox
2018-11-22 21:32 ` [PATCH 1/2] mm: Remove redundant test from find_get_pages_contig Matthew Wilcox
2018-11-23 10:47   ` Kirill A. Shutemov [this message]
2018-11-23 17:59     ` Matthew Wilcox
2018-11-22 21:32 ` [PATCH 2/2] page cache: Store only head pages in i_pages Matthew Wilcox
2018-11-23 10:56   ` Kirill A. Shutemov
2018-11-23 17:19     ` Matthew Wilcox
2018-11-23 17:36       ` Kirill A. Shutemov

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