From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id ADF7A41226B for ; Thu, 2 Jul 2026 08:10:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782979815; cv=none; b=hvTJs5TwJdW4XSwTQSPWBT6v/XVTnvidUE2D8nqm+P7X6CYqqGFMaq+Tb2ahXFBFIYRy8lTtiHjUloHhjGzirSSxcwddCkwT/MfGWwaBd2dDcXs12p0KJ46IE/ilUTHuI4Z6WsGBj8Gw/cwh9uy+ibM2X+DhFnxBpft4jWJ4oi8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782979815; c=relaxed/simple; bh=ny/uAw5342YktFO+LWrmHrrO+KocSWvVZTfnRSPi//w=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=AlMdp0Mk0foxpASbDiZJ+Cr4/KwQtIIuOLAfC0bBTugpDPhg4qCmWaFTBGCQg4e6rpNM+KXoCi0q5UHxFyh7bZvK+61uuAbqSV45hdodl7841J5tBG7jgzL+cbLhces6uzwZT89s8kAwn7GT5MDwEyftYL/l+FgWfbjhr/pIDcM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Oz3A3ojm; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Oz3A3ojm" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D13FA1F000E9; Thu, 2 Jul 2026 08:10:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782979814; bh=Y4CA8drkOIR5FEKtDOUJje3Kyl/a39+WBY6Nj3bBpZ4=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=Oz3A3ojmCliR6ASQn3KTYMNBUQnAWk01ZXcADtIhY17qc3dwknoG3/bwwNIQaEcZA FnzvNqknR70hhD5bKIaPUYrvuJSRB+GWs5m8LuKhMa0jF+FgRgP4pAfDk/84EGYLIc ko2NYqya+3hVAt6G8VDPVKp2TJyJKJLT2ZLuDfzHUoBpJawZWcxsFT1hEiy3d7JVJe wEVXuUNoJ23Ct8q+Vnfb/AX5utZfo5Nd6ECFK701AYjhSc584HJnYhmUBJv0AZUnsv upFKhrxImhqKrjqfONGJJ7AHTZ3lpTXmCWtfzKU1MauixHrjktQOzBESOcxe89g30f 5arCUsxNHsG2Q== Message-ID: Date: Thu, 2 Jul 2026 10:10:07 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 4/4] mm: clarify the folio_free_swap() for do_swap_page() To: "Barry Song (Xiaomi)" , akpm@linux-foundation.org, linux-mm@kvack.org Cc: baoquan.he@linux.dev, chrisl@kernel.org, jp.kobryn@linux.dev, kasong@tencent.com, liam@infradead.org, linux-kernel@vger.kernel.org, ljs@kernel.org, mhocko@suse.com, nphamcs@gmail.com, rppt@kernel.org, shakeel.butt@linux.dev, shikemeng@huaweicloud.com, surenb@google.com, usama.arif@linux.dev, vbabka@kernel.org, youngjun.park@lge.com References: <20260701235955.36126-1-baohua@kernel.org> <20260701235955.36126-5-baohua@kernel.org> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 7/2/26 01:59, Barry Song (Xiaomi) wrote: > Since commit 4b34f1d82c654 ("mm, swap: free the swap cache after > folio is mapped"), we have relied on do_wp_page() to handle the > non-exclusive case, where the folio may either be reused or require > CoW. > > As a result, using the refcount in do_swap_page() to decide when to > free the swap cache is no longer necessary, since do_wp_page() can > handle this more cleanly and consistently. > > We can now simply use FAULT_FLAG_WRITE together with exclusivity to > decide when to free the swap cache in do_swap_page(). > > Suggested-by: David Hildenbrand (Arm) > Signed-off-by: Barry Song (Xiaomi) > --- Acked-by: David Hildenbrand (Arm) -- Cheers, David