From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 EA7221D8DFB; Tue, 8 Oct 2024 14:44:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728398673; cv=none; b=Vj2t3/XD2eM2PmI7onPxMPLj5wGJ7UNfKsu9xCWfSPf8uhLq/oEUvAJuVCewZRUbkOmQIwIGb3nRL9bwvS/+BeJa49++wit+94IHf6wwLjb8R/bccB5bT65YHYj2ATBZsk0zFfSaB2HfexplG5htQP89SJqSi8crWXeWv+QmB0c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728398673; c=relaxed/simple; bh=2r9KIBLL1cXgHzsof+Mzxlou0eXLychanxOKsDI3Vd0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=suJJrF2d/SVktFujCdqDVzHoP4wvf46ofO/ei0T/kCWBfhjZryNOXfw0ajquu7TGqZLw56YmU/Dw1aCdFWjbFav+niiVtmiOHjrtsCxAusb8Gsi6in+DDCHEsG4fvi/s1Kdk15Xrugfqtx8mcoYU57JlJMRB53RdjOdYXXmJsIo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=T7lrx/3E; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="T7lrx/3E" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0CBBDC4CEC7; Tue, 8 Oct 2024 14:44:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1728398672; bh=2r9KIBLL1cXgHzsof+Mzxlou0eXLychanxOKsDI3Vd0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=T7lrx/3EXHxD5qGecNBPZyiltAIxvOthAw23EzR8+WCK20equjsTRP01hX6d0yJZe +lCbO3N2b6N2rPy4uApYGLvbc0a7dSj5P+HKyEpluOg5RbeRjra1pvCwLgLSsJTOkf QUkrjTnusD3AtnS6p542x05JmpzFHhGyftkzX1SovS+Ooqd9rDya9WVOw5ktixC+7W OeDKwd/ZPmfdo82F/3RhCzgITXnXT2iXFPw644evbv1soENfOTupnQxenfAbStRf6O XhApI494qeYFBOcGv5BTfgr7wZq9X4IjgXisT7w9xlfiQSKtyRXRmrKMDSWjNeSQiA 6eLnoFAguPyWA== Date: Tue, 8 Oct 2024 08:44:28 -0600 From: Keith Busch To: Christoph Hellwig Cc: Javier =?iso-8859-1?Q?Gonz=E1lez?= , Jens Axboe , "Martin K. Petersen" , 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: References: <20241003125400.GB17031@lst.de> <20241004053121.GB14265@lst.de> <20241004061811.hxhzj4n2juqaws7d@ArmHalley.local> <20241004062733.GB14876@lst.de> <20241004065233.oc5gqcq3lyaxzjhz@ArmHalley.local> <20241004123027.GA19168@lst.de> <20241007101011.boufh3tipewgvuao@ArmHalley.local> <20241008122535.GA29639@lst.de> Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20241008122535.GA29639@lst.de> On Tue, Oct 08, 2024 at 02:25:35PM +0200, Christoph Hellwig wrote: > On Mon, Oct 07, 2024 at 12:10:11PM +0200, Javier González wrote: > > In summary, what we are asking for is to take the patches that cover the > > current use-case, and work together on what might be needed for better > > FS support. > > And I really do not think it is a good idea. For one it actually > works against the stated intent of the FDP spec. Second extending > the hints to per per-I/O in the io_uring patch is actively breaking > the nice per-file I/O hint abstraction we have right now, and is > really unsuitable when actually used on a file and not just a block > device. And if you are only on a block device I think passthrough > of some form is still the far better option, despite the problems > with it mentioned by Keith. Then let's just continue with patches 1 and 2. They introduce no new user or kernel APIs, and people have already reported improvements using it. Further, it is just a hint, it doesn't lock the kernel into anything that may hinder future inovations and enhancements. So let's unblock users and refocus *our* time to something more productive, please? And to be honest, the per-io hints for generic read/write use is only valuable for my users if metadata is also exposed to userspace. I know Javier's team is working on that in parallel, so per-io hints are a lower priority for me until that part settles.