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Message-ID: <8026a0341c83ceee69d04cbe55f1e0fa3d6cb610.camel@surriel.com>
Subject: Re: [PATCH v9 6/6] mm,thp: avoid writes to file with THP in
 pagecache
From:   Rik van Riel <riel@surriel.com>
To:     Song Liu <songliubraving@fb.com>, linux-mm@kvack.org,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     matthew.wilcox@oracle.com, kirill.shutemov@linux.intel.com,
        kernel-team@fb.com, william.kucharski@oracle.com,
        akpm@linux-foundation.org, hdanton@sina.com
Date:   Thu, 27 Jun 2019 09:18:35 -0400
In-Reply-To: <20190625001246.685563-7-songliubraving@fb.com>
References: <20190625001246.685563-1-songliubraving@fb.com>
         <20190625001246.685563-7-songliubraving@fb.com>
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On Mon, 2019-06-24 at 17:12 -0700, Song Liu wrote:
> In previous patch, an application could put part of its text section
> in
> THP via madvise(). These THPs will be protected from writes when the
> application is still running (TXTBSY). However, after the application
> exits, the file is available for writes.
>=20
> This patch avoids writes to file THP by dropping page cache for the
> file
> when the file is open for write. A new counter nr_thps is added to
> struct
> address_space. In do_last(), if the file is open for write and
> nr_thps
> is non-zero, we drop page cache for the whole file.
>=20
> Reported-by: kbuild test robot <lkp@intel.com>
> Signed-off-by: Song Liu <songliubraving@fb.com>

Acked-by: Rik van Riel <riel@surriel.com>

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