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 7EFFA19F133; Fri, 11 Oct 2024 16:59:08 +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=1728665948; cv=none; b=TBfl78BK3aL+bfOuv4vJIcMYjyWFemMqSSKKTFSIR0zoGiMDdq36pBC29H2sNpxGPtwhMZxSXe/LKtXKLbVCR9FSWvEvyQLVbgQzADwsJ9RAzky9pz8sGu/6osziICACiCundDEfwP6F9ytkLlSCp7M5T+kFm+Fc/f2heCCaLvI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728665948; c=relaxed/simple; bh=mkYGbk6JIVdaR+ngMKVGQQpONnRKTN08+o+35jtWhaw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=K1Ook/gX/dMm9JKMeK7h2z2fGzVGgThPekPpQtEV8fmHXTjw/4UCxh5J1dCP4WP7czFSwOsKRonlSBkEtLKpxY0BWsG4IuTfH+TTY3fWg5BnZwv4aqimpkqYfxYgo6vJMTJ2OEFV2NK1qiRtQC7a2yN8JMuoy46p6AWRekguANw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=XthzRxwl; 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="XthzRxwl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 087ADC4CEC3; Fri, 11 Oct 2024 16:59:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1728665948; bh=mkYGbk6JIVdaR+ngMKVGQQpONnRKTN08+o+35jtWhaw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=XthzRxwlyTwMBL7/dqVToKwmwWz/tmxBQIW9AGGTzEbGctR95F+R+YjqQugDgkuM8 ZSdTLWGDrN9cpZ51C0wJxyeMztsF7Xnui24tVXpK4IRnur7/ZP3iqO0Tus+pEeEM0c LHUarhCe+CYGrvy0yQHbNyjm5pR7UezxR/EfqQ33483z9FLJNAT2s5iNercKVORDh0 p1o9EahbR95h7eZ55BqhKXKbcRHrTuCkVs15ZBP9MtomhvKSdktlzZ2jSNLmLui8Ph v30Z70FuMrkmRWIBObje29CAG014E7yhsJ30Qs6x/3H70RPamvzNp6T1FVHsUr2yVw RDAOSf9awHmUA== Date: Fri, 11 Oct 2024 10:59:05 -0600 From: Keith Busch To: Javier Gonzalez Cc: Christoph Hellwig , Hans Holmberg , Jens Axboe , Christian Brauner , "Martin K. Petersen" , Kanchan Joshi , "hare@suse.de" , "sagi@grimberg.me" , "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: <20241007101011.boufh3tipewgvuao@ArmHalley.local> <97bd78a896b748b18e21e14511e8e0f4@CAMSVWEXC02.scsc.local> <20241010071327.rnh2wsuqdvcu2tx4@ArmHalley.local> <20241010092010.GC9287@lst.de> <20241010122232.r2omntepzkmtmx7p@ArmHalley.local> <20241011085631.GA4039@lst.de> <20241011122102.znguf6kpmbbsa42t@ArmHalley.local> 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=us-ascii Content-Disposition: inline In-Reply-To: <20241011122102.znguf6kpmbbsa42t@ArmHalley.local> On Fri, Oct 11, 2024 at 02:21:02PM +0200, Javier Gonzalez wrote: > > That's a lot of marketing babble :) What exact thing is missing > > from the passthrough interface when using say spdx over io_uring? > > The block layer provides a lot of functionality that passthru cannot > provide. A simple example would be splits. You know this :) > > I am sure Jens and Keith can give you more specifics on their particular > reasons. Splitting, merging, cgroups, iostats, error retries, failover. We have a recent change staged in 6.13 to try to count iostats on passthrough, but it doesn't do discards. Passthrough to partitions requires root access and the slow CAP_SYSADMIN check on every IO. Page cache. Though that may not readily work with this io_uring proposal as-is either. The generic IO path is safe to changing formats; passthrough isn't. And it's just generally more work to port existing applications to use the passthrough interface. It causes duplicating solutions to scenarios the kernel already handles.