From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) (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 E1E7817BB14 for ; Mon, 12 Aug 2024 13:38:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.95.11.211 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723469929; cv=none; b=ipsroQAbIR4OYckdGTJe4DM0oc3JAaAXGY/iYPfo39iMXwuvE+gBSAWqxEQGlzNrmx3ldk1DB+K4coPIjD8v3CFhgG6uUJ5RuJbXEGnVtFREohsM04sKDP7d1BHftprgNZda6dNwCHWecW2owPxw+r6FtXgwdYuVuU5xbeIb+Dg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723469929; c=relaxed/simple; bh=i2TopCfxA35jt5R9+xgsJwJF5Hih2D+XHUrfqA1tags=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=rDC/btfZnnvo/yWdGAgmnOA5CoWNT43jYvV2hbMM/J6kicxYeU0D98VrO6GelEnLZujaIldJ8osGtnKpq2gYF2yZFCphpYp88dSFLuAQUaBq3AHIQBPW2r17Y+eRLGGqqsy2bVs7bn6mOLWP1KCArQVY3MEB16rMCMyNUGk+8f8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de; spf=pass smtp.mailfrom=lst.de; arc=none smtp.client-ip=213.95.11.211 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=lst.de Received: by verein.lst.de (Postfix, from userid 2407) id 27577227A87; Mon, 12 Aug 2024 15:38:44 +0200 (CEST) Date: Mon, 12 Aug 2024 15:38:43 +0200 From: Christoph Hellwig To: Luis Chamberlain Cc: Kundan Kumar , Daniel Gomez , Pankaj Raghav , kernel@pankajraghav.com, axboe@kernel.dk, hch@lst.de, willy@infradead.org, kbusch@kernel.org, linux-block@vger.kernel.org, joshi.k@samsung.com, anuj20.g@samsung.com, nj.shetty@samsung.com, c.gameti@samsung.com, gost.dev@samsung.com Subject: Re: [PATCH v8 0/5] block: add larger order folio instead of pages Message-ID: <20240812133843.GA24570@lst.de> References: <20240711050750.17792-1-kundan.kumar@samsung.com> Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) On Thu, Aug 08, 2024 at 04:04:03PM -0700, Luis Chamberlain wrote: > This is not just about mTHP uses though, this can also affect buffered IO and > direct IO patterns as well and this needs to be considered and tested as well. Not sure what the above is supposed to mean. Besides small tweaks to very low-level helpers the changes are entirely in the direct I/O path, and they optimize that path for folios larger than PAGE_SIZE. > I've given this a spin on top of of the LBS patches [0] and used the LBS > patches as a baseline. The good news is I see a considerable amount of > larger IOs for buffered IO and direct IO, however for buffered IO there > is an increase on unalignenment to the target filesystem block size and > that can affect performance. Compared to what? There is nothing in the series here changing buffered I/O patterns. What do you compare? If this series changes buffered I/O patterns that is very well hidden and accidental, so we need to bisect which patch does it and figure out why, but it would surprise me a lot.