From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2EA23C678D5 for ; Sat, 4 Mar 2023 17:17:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229484AbjCDRRk (ORCPT ); Sat, 4 Mar 2023 12:17:40 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34562 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229447AbjCDRRj (ORCPT ); Sat, 4 Mar 2023 12:17:39 -0500 Received: from smtp-out1.suse.de (smtp-out1.suse.de [IPv6:2001:67c:2178:6::1c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D7AFB6E94; Sat, 4 Mar 2023 09:17:38 -0800 (PST) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 8024B22B84; Sat, 4 Mar 2023 17:17:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1677950257; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=1ffr+G/XTnNX5sutfA/xaUbfn1Y64DxDY55IeB5PEHY=; b=jfpVqDVMSXSe5Kq65s+A/aMIMODTc90cu5nvrpGe/m0n9f7BYyfc1J9jO/0YG0EI6UQlps s1wTUxaly4GG92KrO/OyEgdXyv8TjuYw+bjLklFfZ5BCh7z1MJKdyKHQorIZ3LFP5BzT/D xBDATOkexNyh05PZiU/bi/Ql+6/UvDk= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1677950257; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=1ffr+G/XTnNX5sutfA/xaUbfn1Y64DxDY55IeB5PEHY=; b=VWkOtwNFuAnKnmMJhHMOf6Jj6F51bxUu1xH0SizlXF05QL4Ajf0oiziZSOFJoufQZAGSPU pXQ0OlHfgSVkecAg== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 0E9B213901; Sat, 4 Mar 2023 17:17:37 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id g6arAjF9A2R5NgAAMHmgww (envelope-from ); Sat, 04 Mar 2023 17:17:37 +0000 Message-ID: Date: Sat, 4 Mar 2023 18:17:35 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.6.1 Subject: Re: [LSF/MM/BPF TOPIC] Cloud storage optimizations Content-Language: en-US To: Matthew Wilcox Cc: Luis Chamberlain , Keith Busch , Theodore Ts'o , Pankaj Raghav , Daniel Gomez , =?UTF-8?Q?Javier_Gonz=c3=a1lez?= , lsf-pc@lists.linux-foundation.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-block@vger.kernel.org References: From: Hannes Reinecke In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 3/4/23 17:47, Matthew Wilcox wrote: > On Sat, Mar 04, 2023 at 12:08:36PM +0100, Hannes Reinecke wrote: >> We could implement a (virtual) zoned device, and expose each zone as a >> block. That gives us the required large block characteristics, and with >> a bit of luck we might be able to dial up to really large block sizes >> like the 256M sizes on current SMR drives. >> ublk might be a good starting point. > > Ummmm. Is supporting 256MB block sizes really a desired goal? I suggest > that is far past the knee of the curve; if we can only write 256MB chunks > as a single entity, we're looking more at a filesystem redesign than we > are at making filesystems and the MM support 256MB size blocks. > Naa, not really. It _would_ be cool as we could get rid of all the cludges which have nowadays re sequential writes. And, remember, 256M is just a number someone thought to be a good compromise. If we end up with a lower number (16M?) we might be able to convince the powers that be to change their zone size. Heck, with 16M block size there wouldn't be a _need_ for zones in the first place. But yeah, 256M is excessive. Initially I would shoot for something like 2M. > The current work is all going towards tracking memory in larger chunks, > so writing back, eg, 64kB chunks of the file. But if 256MB is where > we're going, we need to be thinking more like a RAID device and > accumulating writes into a log that we can then blast out in a single > giant write. > Yeah. I _do_ remember someone hch-ish presenting something two years back at ALPSS, but guess that's still on the back-burner. Cheers, Hannes -- Dr. Hannes Reinecke Kernel Storage Architect hare@suse.de +49 911 74053 688 SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew Myers, Andrew McDonald, Martje Boudien Moerman