From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A38A8CF8859 for ; Thu, 20 Nov 2025 13:29:36 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id BA0EA6B0007; Thu, 20 Nov 2025 08:29:35 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id B78906B0088; Thu, 20 Nov 2025 08:29:35 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AB6796B0089; Thu, 20 Nov 2025 08:29:35 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 9C0376B0007 for ; Thu, 20 Nov 2025 08:29:35 -0500 (EST) Received: from smtpin22.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 0223C1374A7 for ; Thu, 20 Nov 2025 13:29:32 +0000 (UTC) X-FDA: 84131067426.22.96BD0BD Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf07.hostedemail.com (Postfix) with ESMTP id 4F62040003 for ; Thu, 20 Nov 2025 13:29:31 +0000 (UTC) Authentication-Results: imf07.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=dFxAWLwk; spf=pass (imf07.hostedemail.com: domain of david@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=david@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1763645371; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=YEEvDbIkq+Y5Mpl0rYfxoGsCGene+u0KC3g+KuciChU=; b=W1yP5qQjMMBilqgymIggyDsXn1U29BnfWoBzbwlfsS4Ehjo6NNHRJS55jLN9m8S686GXlz /IYEuvBlTWlayOT7KwjHS9anjS29fTvUKi9i9nCZZtM6MwtiMcVfDOR+a7EnASX0s5SnbO Y/AcYZPedm90n3rWXcI1vMEDCNKUijs= ARC-Authentication-Results: i=1; imf07.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=dFxAWLwk; spf=pass (imf07.hostedemail.com: domain of david@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=david@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1763645371; a=rsa-sha256; cv=none; b=kFTeN/dbqe/UIq6+Wg/qsmfBv7b+IYo9VroPe49x3N4yESdD2mx5sXiB2CawYiO5AJ3cNS 4SmauyRwSsflEmkZl17vJ3pcyO3vue8UcJ1vtVjeIXWtg5s5eyALK3MqAnSTahJfnM9r2c V1EUegD89yg1T0UiX6heUKJNTAUuBiI= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 9EBF960159; Thu, 20 Nov 2025 13:29:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 696B2C4CEF1; Thu, 20 Nov 2025 13:29:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1763645370; bh=WZU8YZVNbH9FupGqUrgw5DmUou46sjiYKi37MvqORC8=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=dFxAWLwkeJpmG95tU1YvLqrMFtE1xoY8AMaETQkrrGe8tU5jkl/iVac4wQudxnxY1 KhPrO9vx2YTdf90paFpoS7c84BMBaBn8bo979ASlHAC+jJi3qTeKDIj/6mCTvyQwRh ZmfJdYunou9FlkmnekDBfMeM0IoCbbrAF48rrujI5XOjtCoqAWXh+uChbl/DzV9mB6 75Cmv+9JGkDrlMPffuEGxVacn5h7I0NSCpUgI6VqACNET/MkhqZFmInU+Bfrv2g8pL O6DINDJsLkG+Q1kuMCJjKyN83HUHi74xMqfGW9D29Gzv6x5IWaZfnqVJUlPl2I8dYb Vvy4xYKZuM/LA== Message-ID: <81e34d93-9031-4840-a0d0-56d488f3bc17@kernel.org> Date: Thu, 20 Nov 2025 14:29:23 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH V2 2/2] mm/khugepaged: map dirty/writeback pages failures to EAGAIN To: Lance Yang , "Garg, Shivank" , Dev Jain Cc: Zi Yan , Baolin Wang , "Liam R . Howlett" , Nico Pache , Ryan Roberts , Barry Song , Andrew Morton , Steven Rostedt , Lorenzo Stoakes , Masami Hiramatsu , Mathieu Desnoyers , Zach O'Keefe , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org References: <20251120065043.41738-6-shivankg@amd.com> <20251120065043.41738-10-shivankg@amd.com> <6c1d6b80-d290-4110-9a49-53e7404136bc@arm.com> <33476cb4-318b-49db-9cc1-a354eca9e883@amd.com> From: "David Hildenbrand (Red Hat)" Content-Language: en-US In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 4F62040003 X-Stat-Signature: 8yinqey1sebmyobghdn1ao9u6qy94ont X-Rspam-User: X-HE-Tag: 1763645371-447437 X-HE-Meta: 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 k80NOl5G 5ze2RygrvGroB4o/sC60+TLyNbSgrrOaWhCRYL7q5SmspsMvmGar9Ixu3qWCM5YQ1V7dUMaVNS8eVPyUvZ0Vw4yPpFd1Gqm29EGIG4S6We7fViG2Sd9Hqs1NNcZUBLyrbGxXa62vo4D9aJd7NN9uYF78i8s3X1hnS6tD8e2/4/kJAYaLkmPFxu3BCDhHKX18KWsVbDsIjoPsmQRzLF93mcbmsbUzKKXETWZgpialb0LrQhl+KhTydBs2ZdEZQ8AFwKpxGizb4/wBzRqGv7x6ZuMhS4q5OXg4v6W1gAj/nrOj9Hnx8OGY7E765lkQxpePI/9oqD3tH+UJwiECkDW9pIxPp+Q== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 11/20/25 13:24, Lance Yang wrote: > > > On 2025/11/20 16:17, Garg, Shivank wrote: >> >> >> On 11/20/2025 1:33 PM, Dev Jain wrote: >>> >>> On 20/11/25 12:20 pm, Shivank Garg wrote: >> >>> SCAN_PAGE_NOT_CLEAN is confusing - NOT_CLEAN literally means dirty, so why not SCAN_PAGE_DIRTY? >>> Or SCAN_PAGE_DIRTY_OR_UNDER_WRITEBACK? Since folio_test_writeback() is true as a result of >>> the folio being dirty, maybe just SCAN_PAGE_DIRTY can do. >>> >>> Reviewed-by: Dev Jain >>> >> Thanks for the review. >> >> I chose not to use SCAN_PAGE_DIRTY because dirty and writeback have different meanings[1]: >> >> Dirty: Memory that is waiting to be written back to disk >> Writeback: Memory that is actively being written back to disk >> >> [1] https://www.kernel.org/doc/Documentation/filesystems/proc.txt >> >> IIUC, a page under writeback is no longer dirty, so using SCAN_PAGE_DIRTY would be misleading >> for pages in the writeback state. >> >> I considered SCAN_PAGE_DIRTY_OR_WRITEBACK initially but felt it was too long. > > Nit: If SCAN_PAGE_DIRTY_OR_WRITEBACK I would prefer that here. -- Cheers David