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 56A1420A5E2; Fri, 11 Oct 2024 08:59:10 +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=1728637151; cv=none; b=WJUmet6Z5cxMBE6C/Lo/Wlc/GinRObko13m5jegbqcXysUXCMKA3qk0eMGLd80vO+q71tn8/Q2EcUmUx+G4qpTNN7L+2yHWXk19io2tCm4b3kbZe/2T7ACH6VxL+Dj4Gs72Uy0c5S/lpiMq59mnvE6nl4m2fjd6U8wd1BBHP5jA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728637151; c=relaxed/simple; bh=ZVTcQl479qU7T/y4VhpPLy5n3CRAWbyJUTE+jOV6E8Q=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=MV8QGGavqbYqRkFJWKw8cProlsVliYkpPiY0rA+XBsLrE4Ku4M93n5SJA1wWOyey2ULq0gzg8UFp56fhcRreswGiRze+vyca+/vfQXMUula6wrS+e4j+gqyiysmc3canGGdiY7hyolyS8werqqdpAm/iyUTCwwOk2GT0qOQ5+pQ= 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 EBA6F227AB3; Fri, 11 Oct 2024 10:59:04 +0200 (CEST) Date: Fri, 11 Oct 2024 10:59:04 +0200 From: Christoph Hellwig To: Javier Gonzalez Cc: Hans Holmberg , Christoph Hellwig , Jens Axboe , "Martin K. Petersen" , Keith Busch , Kanchan Joshi , "hare@suse.de" , "sagi@grimberg.me" , "brauner@kernel.org" , "viro@zeniv.linux.org.uk" , "jack@suse.cz" , "jaegeuk@kernel.org" , "bcrl@kvack.org" , "dhowells@redhat.com" , "bvanassche@acm.org" , "asml.silence@gmail.com" , "linux-nvme@lists.infradead.org" , "linux-fsdevel@vger.kernel.org" , "io-uring@vger.kernel.org" , "linux-block@vger.kernel.org" , "linux-aio@kvack.org" , "gost.dev@samsung.com" , "vishak.g@samsung.com" Subject: Re: [PATCH v7 0/3] FDP and per-io hints Message-ID: <20241011085904.GB4039@lst.de> References: <20241004065233.oc5gqcq3lyaxzjhz@ArmHalley.local> <20241004123027.GA19168@lst.de> <20241007101011.boufh3tipewgvuao@ArmHalley.local> <97bd78a896b748b18e21e14511e8e0f4@CAMSVWEXC02.scsc.local> <20241010071327.rnh2wsuqdvcu2tx4@ArmHalley.local> <20241010122733.bv7vxemqnxr573pz@ArmHalley.local> Precedence: bulk X-Mailing-List: linux-fsdevel@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: <20241010122733.bv7vxemqnxr573pz@ArmHalley.local> User-Agent: Mutt/1.5.17 (2007-11-01) On Thu, Oct 10, 2024 at 02:27:33PM +0200, Javier Gonzalez wrote: [full quote snipped, it would be really helpful to only quote what you actuall reference per the usual email rules] >> Data placement by-file is based on that the lifetime of a file's data >> blocks are strongly correlated. When a file is deleted, all its blocks >> will be reclaimable at that point. This requires knowledge about the >> data placement buckets and works really well without any hints >> provided. > > But we need hints to put files together. I believe you do this already, > as no placement protocol gives you unlimited separation. The per-file temperature hints do a reasonable job for that. A fully developed version of the separate write streams submitted by Kanchan would probably do even better, but for now the per-file hints seem to be enough. > Maybe you can post some patches on the parts dedicated to the VFS level > and user-space API (syscall or uring)? It's just using the existing temperature hints.