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 464191DF24D; Thu, 17 Oct 2024 15:46:55 +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=1729180016; cv=none; b=rp0e4UFgJc078oJxN1dYjhAJNMlgrt7HgIZ1Tsc3YQvPU0ia7QcN7N5Bz8DxyjXkfw0QOeR9Dist97ojhgvjrTbRVnL68ktIYPP+KRbaZ/UI9soscglZT3UNorpV5obJ4ppSpY4osqSWsuS9unFKI4U843xcXMyOJzUIbVSZeZs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729180016; c=relaxed/simple; bh=LJ9ADl/GZSqKR8fNykBSMVYl2SSHt5Snbnb2ygYLwXY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=UcnkXuUs5L+jPx2U2vfY7nmlFvsVzgTWssv2uOYnrCmySTl5dObNPyDEYsEx6oae/+q258zgL/+6tBnd2FEkOz9RkF5qZS6F8SAPjuo9/mqSj3kX7YC5c4yMbm2zRV8Spv3FqvCDGIhFqQjXlzevKs9YO+CdML69th08DlRd8qM= 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 E6EEF227A8E; Thu, 17 Oct 2024 17:46:49 +0200 (CEST) Date: Thu, 17 Oct 2024 17:46:49 +0200 From: Christoph Hellwig To: Keith Busch Cc: Christoph Hellwig , Kanchan Joshi , axboe@kernel.dk, hare@suse.de, sagi@grimberg.me, martin.petersen@oracle.com, 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, javier.gonz@samsung.com Subject: Re: [PATCH v7 0/3] FDP and per-io hints Message-ID: <20241017154649.GA27203@lst.de> References: <20240930181305.17286-1-joshi.k@samsung.com> <20241015055006.GA18759@lst.de> <8be869a7-c858-459a-a34b-063bc81ce358@samsung.com> <20241017152336.GA25327@lst.de> 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: User-Agent: Mutt/1.5.17 (2007-11-01) On Thu, Oct 17, 2024 at 09:44:39AM -0600, Keith Busch wrote: > I'm replying just to make sure I understand what you're saying: > > If we send per IO hints on a file, we could have interleaved hot and > cold pages at various offsets of that file, so the filesystem needs an > efficient way to allocate extents and track these so that it doesn't > interleave these in LBA space. I think that makes sense. That's a little simplified, but yes. > We can add a fop_flags and block/fops.c can be the first one to turn it > on since that LBA access is entirely user driven. Yes, that's my main request on the per-I/O hint interface. Now we just need to not dumb down the bio level interface to five temeperature level and just expose the different write streams and we can all have a happy Kumbaya.