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 7F4013D333D for ; Mon, 20 Jul 2026 09:30:07 +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=1784539808; cv=none; b=EJDVILmcEk9pUpCNOGtj/rKsX+PlzhSJYg2ITsmNNPatFREDDLXmnjzKo4q4edHeVvO/clq5LiV1Ql7FDhS1hEIxSDfJ83u4PFhUbcu0J/f4UzAI0CcMElQiVR+Em8txC46HvGUBjOoqG41SWjzYjSeAynLzZQoi7jpw7nPOxnA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784539808; c=relaxed/simple; bh=vDFHCPUOHJ4ZgwzApEb2w/is+cGwGhXcgQTEB0Rg8hQ=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=ox6QJ/tg8OAQJmhBrDQ5nq+HRg5EYIVpQYlDn3SeIo5y0CMydMW9eJmIzsRnFbyYGoSA2XTmWhecjeQLSuMqKCSnZ42WXZ+ZV/n1X104KMzL9qaIiPuVMB/U9kWu5stb9tWaVskGpX5imTbt/iRD2KoBGo+qD3kBi2hDOy3ZsK4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=fyLxYwAI; 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="fyLxYwAI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 97AB91F000E9; Mon, 20 Jul 2026 09:30:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784539807; bh=jiYeVsnBdIvFuQsIGCzuuAuxcFGL3XUJywevOqwgEe4=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=fyLxYwAIg5Ni1Hk+A0p2yIhUb7gIsYKAJdb8yjiUhm8CLIdJ5Vh1hd96FbCNZLwm8 5pUAFO+AygfYbbH0pW5ennR/j97lDiGgd3TAm0sZDRtqa6IB4/J+qF1QH+GtoQNe8M P3w+i6/wRs2FHfUOF7UkvcPSZlrTNo7MvWBIrDwugfBrQIropv3e4IRaEnlkqcX8BP yyJBXPb97xkn/l0eO4kTKcpNzzi4+T8r1y3YJu7bPFcu/n8PFohsRYw9hd0444di1p C9JIyU/OHWOM8pJVXrjlRMPEKZafOIb53Wky/6b11EUnAGpO8bhmkFzMUOKRTbt/6F /gsWbWCSXzcOQ== Message-ID: <1147ca8f-166a-4236-98b4-0a37442cae1d@kernel.org> Date: Mon, 20 Jul 2026 10:30:02 +0100 Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 2/3] fs: stable_page_flags(): use folio_test_*() helpers To: Jinjiang Tu , akpm@linux-foundation.org, ziy@nvidia.com, luizcap@redhat.com, willy@infradead.org, linmiaohe@huawei.com, svetly.todorov@memverge.com, xu.xin16@zte.com.cn, chengming.zhou@linux.dev, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Cc: wangkefeng.wang@huawei.com, sunnanyong@huawei.com References: <20260720033021.4091944-1-tujinjiang@huawei.com> <20260720033021.4091944-3-tujinjiang@huawei.com> 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 7/20/26 04:30, Jinjiang Tu wrote: > Since commit 304daa8132a9 ("maps4: add /proc/kpageflags interface"), > /proc/kpageflags directly operates on page->flags to determine page status. > Later, commit 177975495914 ("proc: export more page flags in > /proc/kpageflags") started using page helper functions when exposing new > flags, leading to a mix of both approaches. > > For tail pages, the original code did not return corresponding status. > commit 0a71649cb724 ("/proc/kpageflags: return KPF_SLAB for slab tail > pages") and commit 832fc1de01ae ("/proc/kpageflags: return KPF_BUDDY for > "tail" buddy pages") made tail slab/buddy pages also return corresponding > status. Then commit dee3d0bef2b0 ("proc: rewrite stable_page_flags()") > made all tail pages return the same status as their head page, except for > hwpoison and mapped flags. It also cached the folio's flags and operate on > the flags directly to avoid concurrency issues if using folio_test_*() > helpers. > > Since commit 476d87d6a061 ("fs: stable_page_flags(): use snapshot_page()"), > we can now safely switch to folio_test_*() helpers instead of directly > operating on flags, which is more readable and consistent with the rest of > the kernel. Only convert cfolio-specific flags (i.e., anon, ksm, swapcache) > to folio_test_*() helpers, which reduces redundant code. Keep others > unchanged due to they aren't folio-specific flags or coverting them doesn't > cleanup. > > No functional change is intended. > > Signed-off-by: Jinjiang Tu Acked-by: David Hildenbrand (Arm) -- Cheers, David