From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailout1.samsung.com (mailout1.samsung.com [203.254.224.24]) (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 7FAE42DAFDE for ; Fri, 29 Aug 2025 09:00:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=203.254.224.24 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756458014; cv=none; b=l0aaL2LtrJ+CHc1rsa9djYcUZvz1NLgWEayV/DRPKRovhtj9V0H9qd+zmvv6CjSm1rXy2bgCDAerdQ6P+gwm5yAZfapHsszqJJAnqQu0aoWkkWXTJ6YBUzFHhyVi/FiUb/88MQ8j5Jvs+ndDWcukUlkaC7YmrLLW7iqayDYkTlA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756458014; c=relaxed/simple; bh=fQwb9mM6knMDr3YCfsYeFWVuYqVoePVMApjpt3F4KwM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:From:In-Reply-To: Content-Type:References; b=IBZbDG4Coq29zpM9AzEdALTbTOYQO7Cz0ckZKe7KkeYieAfQOCHJJnlEcLQLwgqAWznnyOZXk3d6uuXp874T7ISqdFCy/hDaPMiyLLDOP2iw0Ggi6YqSLCFqDEKk9Qusd6kXYB/+dkQQYevowVEa7BUECLZOJSC0QmX2AhtdtCw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=samsung.com; spf=pass smtp.mailfrom=samsung.com; dkim=pass (1024-bit key) header.d=samsung.com header.i=@samsung.com header.b=egCHoD49; arc=none smtp.client-ip=203.254.224.24 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=samsung.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=samsung.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=samsung.com header.i=@samsung.com header.b="egCHoD49" Received: from epcas5p3.samsung.com (unknown [182.195.41.41]) by mailout1.samsung.com (KnoxPortal) with ESMTP id 20250829090004epoutp01eb0fe1cc13c6d69f48d042d934e34a57~gMT-BlgLs3145531455epoutp01W for ; Fri, 29 Aug 2025 09:00:04 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 mailout1.samsung.com 20250829090004epoutp01eb0fe1cc13c6d69f48d042d934e34a57~gMT-BlgLs3145531455epoutp01W DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=samsung.com; s=mail20170921; t=1756458004; bh=uRfid9eNRN1IiYiLsnEKYQu88MjmvxZl3zgdA6RmIhE=; h=Date:Subject:To:Cc:From:In-Reply-To:References:From; b=egCHoD49xR6PtICey0GDtw4Sx59Y7VZ4nxmF9kVPG855KI8bIk1gqEXodlTOF9RRf u+i31C5oz8l1xOSb1cDjYRZqZUyUd8EyVDSJhUD7BAEzON/nxdGDj+7xhU9FTVYYlU 3Pt3ARQk2w2GfCKDhMpfbEvlhydzmq3zfweJMdOQ= Received: from epsnrtp04.localdomain (unknown [182.195.42.156]) by epcas5p3.samsung.com (KnoxPortal) with ESMTPS id 20250829090003epcas5p36bada7713dea2fb6f6cc6883fb86363e~gMT_Hgm1i2928729287epcas5p3p; Fri, 29 Aug 2025 09:00:03 +0000 (GMT) Received: from epcas5p1.samsung.com (unknown [182.195.38.93]) by epsnrtp04.localdomain (Postfix) with ESMTP id 4cCsfV5rzjz6B9m5; Fri, 29 Aug 2025 09:00:02 +0000 (GMT) Received: from epsmtip2.samsung.com (unknown [182.195.34.31]) by epcas5p1.samsung.com (KnoxPortal) with ESMTPA id 20250829090001epcas5p1624018975802eceeb655e76bf63d152a~gMT8VfSQU1933919339epcas5p17; Fri, 29 Aug 2025 09:00:01 +0000 (GMT) Received: from [107.111.86.57] (unknown [107.111.86.57]) by epsmtip2.samsung.com (KnoxPortal) with ESMTPA id 20250829085958epsmtip2c5f994338290c8c07053baa5737e55fe~gMT5u6ee93040930409epsmtip2G; Fri, 29 Aug 2025 08:59:58 +0000 (GMT) Message-ID: <77291508-cd85-4889-8502-73eb834e543c@samsung.com> Date: Fri, 29 Aug 2025 14:29:57 +0530 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: [RFC 0/1] writeback: add sysfs to config the number of writeback contexts Content-Language: en-US To: wangyufei , Andrew Morton , David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , "Matthew Wilcox (Oracle)" , Stephen Rothwell , open list , "open list:MEMORY MANAGEMENT - MISC" , "open list:PAGE CACHE" Cc: anuj20.g@samsung.com, hch@lst.de, bernd@bsbernd.com, djwong@kernel.org, jack@suse.cz, opensource.kernel@vivo.com From: Kundan Kumar In-Reply-To: <20250825122931.13037-1-wangyufei@vivo.com> Content-Transfer-Encoding: 7bit X-CMS-MailID: 20250829090001epcas5p1624018975802eceeb655e76bf63d152a X-Msg-Generator: CA Content-Type: text/plain; charset="utf-8" CMS-TYPE: 105P cpgsPolicy: CPGSC10-542,Y X-CFilter-Loop: Reflected X-CMS-RootMailID: 20250825123009epcas5p1573496e2cad2f58d22036493e5af03be References: <20250825122931.13037-1-wangyufei@vivo.com> On 8/25/2025 5:59 PM, wangyufei wrote: > Hi everyone, > > We've been interested in this patch about parallelizing writeback [1] > and have been following its discussion and development. Our testing in > several application scenarios on mobile devices has shown significant > performance improvements. > Hi, Thanks for sharing this work. Could you clarify a few details about your test setup? - Which filesystem did you run these experiments on? - What were the specifics of the workload (number of threads, block size, I/O size)? - If you are using fio, can you please share the fio command. - How much RAM was available on the test system? - Can you share the performance improvement numbers you observed? That would help in understanding the impact of parallel writeback? I made similar modifications to dynamically configure the number of writeback threads in this experimental patch. Refer to patches 14 and 15: https://lore.kernel.org/all/20250807045706.2848-1-kundan.kumar@samsung.com/ The key difference is that this change also enables a reduction in the number of writeback threads. Thanks, Kundan >