From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 68C153D69; Sat, 29 Jun 2024 06:25:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719642339; cv=none; b=iZ6qJdddIli5gRjemik3w5FSVEllcSWc+FnJrQc4+RquAUHTgVWUxidaHDTmiBiezYVUn0gAjq39FuF0lm9SyZfgtHt+EfRUzME/cO8digj39dHmKL0BoaUJfSohgjc3+Dz5tRqpORyl2GlXDyMj/JS8qOx4cwzchvXtHxqBAiI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719642339; c=relaxed/simple; bh=fs48/52NADoG38JxBDzweblcs7YENA8fbMWo1V11K3E=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=PpoqJ2OUSrVV4VpVxLeoe1OFeLvKEc7rJiebol9AbFXW/Zi3qzaZaqL3x9fBuc/slpLXkP2DaAH5lMQh5RYPUk6n/MnzxgkTz5AMG+tg5AX2+uwvGpowtLV7+EPrlzxfEdLBEPVNZLA8PP89JhVuTVFevQLCw3eCrEn51GTScs8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=cbPxcAT3; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="cbPxcAT3" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=jF9YptaNEcUba9vHIIDGNCL4tXi5jsBItIWsaKNJPwg=; b=cbPxcAT3Gh3u2Oz3d7cmQVA67k 347sgcuute+AWlp4+E7nY+LkVucOZZalnmncbVo28Ij1pWEBh87fgItCyKJUbmUKDuFXSmSGxjnag JtrpNd5T6b57FdFYWoeycdTF+hQwU20E6FjE9hu1qIQUzTktVbPkhd+vQIP7Akg431skZZhkHev1j 23nQWUdYuEKMBFWH6FeezVP08ObPx8gl4GxgxAITn6pkvvkGd4lN49Dxiw0mavc1MOagQjwlyb87+ hLmTLtV25YjxKuD5ihXB8J92uBMslXNFAV9dEk9XqoZIdYZXmlNrhV6spFSu0xi2CfZ9QHQtmWUjL Z8VBY0Jw==; Received: from hch by bombadil.infradead.org with local (Exim 4.97.1 #2 (Red Hat Linux)) id 1sNRWg-0000000G0B4-2Z6g; Sat, 29 Jun 2024 06:25:34 +0000 Date: Fri, 28 Jun 2024 23:25:34 -0700 From: Christoph Hellwig To: Luis Chamberlain Cc: p.raghav@samsung.com, hare@suse.de, kbusch@kernel.org, david@fromorbit.com, neilb@suse.de, gost.dev@samsung.com, linux-block@vger.kernel.org, linux-mm@kvack.org, patches@lists.linux.dev Subject: Re: [RFC] bdev: use bdev_io_min() for statx DIO min IO Message-ID: References: <20240628212350.3577766-1-mcgrof@kernel.org> 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: <20240628212350.3577766-1-mcgrof@kernel.org> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Fri, Jun 28, 2024 at 02:23:50PM -0700, Luis Chamberlain wrote: > We currently rely on the block device logical block size for the > offset alignment. While this *works* it doesn't work with performance > in mind. That's exactly what the minimum_io_size attribute is for. > > This would for example enhance performance for DIO on 4k IU drives which > have for example an LBA format of 512 bytes for both HDDs and NVMe. > Another use case is to ensure that DIO will be used with 16k IOs on > existing market 16k IU drives with an LBA format of 4k or 512 bytes. The minimum_io_size clearly is the minimum I/O size, not the minimal nice to have one. Changing this will break existing setups.