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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 92242CA1010 for ; Fri, 5 Sep 2025 06:58:07 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id D443E8E0002; Fri, 5 Sep 2025 02:58:06 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id CF4BC8E0001; Fri, 5 Sep 2025 02:58:06 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BBD548E0002; Fri, 5 Sep 2025 02:58:06 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id A916F8E0001 for ; Fri, 5 Sep 2025 02:58:06 -0400 (EDT) Received: from smtpin22.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 51985140578 for ; Fri, 5 Sep 2025 06:58:06 +0000 (UTC) X-FDA: 83854292172.22.2B40028 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.223.131]) by imf10.hostedemail.com (Postfix) with ESMTP id 243B9C000D for ; Fri, 5 Sep 2025 06:58:02 +0000 (UTC) Authentication-Results: imf10.hostedemail.com; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=y8z22so3; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=0IzuDVqN; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=y8z22so3; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=0IzuDVqN; spf=pass (imf10.hostedemail.com: domain of vbabka@suse.cz designates 195.135.223.131 as permitted sender) smtp.mailfrom=vbabka@suse.cz; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1757055484; h=from:from:sender:reply-to:subject:subject: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:dkim-signature; bh=TvK9ixWwRei4oCEeYPKW9uWdDzojNqzJFZHBSy8S3W0=; b=oLqjyytGPxxIq1Av5iPhja9JxTkPyJLozwcSDfThyqLiv2nS+Tu+XI6ivj844ENpVG2RAm 2l1MbAvSI6vSzXTjEAW5IjSAzZy6fbRgjnfIVbKP25Y4pBe2dEeLazHd9E8EmUIwLNG6QO dbwmYBDRfHaasiu1wAAF4GTz1mbgcOY= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1757055484; a=rsa-sha256; cv=none; b=lXdNuOoXzEhtqxG7QYHyqrNBrVOMEZKBAK6khGivQzDQoeIoB6hhbGG6OBwCc4KoAudqph 35Z6aO5p+LpDQEL32qmzYwd3LkeWSbbY0MiD5AAuEWCZbGaFFQukSLAzFsNrz9srSicD6y dgRhI73U4uNU232c9CmFsqiq2INvEuo= ARC-Authentication-Results: i=1; imf10.hostedemail.com; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=y8z22so3; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=0IzuDVqN; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=y8z22so3; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=0IzuDVqN; spf=pass (imf10.hostedemail.com: domain of vbabka@suse.cz designates 195.135.223.131 as permitted sender) smtp.mailfrom=vbabka@suse.cz; dmarc=none Received: from imap1.dmz-prg2.suse.org (imap1.dmz-prg2.suse.org [IPv6:2a07:de40:b281:104:10:150:64:97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 2C60F76F71; Fri, 5 Sep 2025 06:58:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1757055481; 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:autocrypt:autocrypt; bh=TvK9ixWwRei4oCEeYPKW9uWdDzojNqzJFZHBSy8S3W0=; b=y8z22so3t/LCPlVSsXuM4LY9tNaUh5bXHnsvWbMk+++SMpnxNiV0jh2PkM2xRdiMVVgWRM fjhdyHbrnbswMmoOgZvWmod1KYfcJ/MLcbWyfDyK3ch+XjDanm19thfdhk7SjBnIhZ15qi 7C+UfHVOwxuAdwpPrQnvCMGXZgFz1ao= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1757055481; 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:autocrypt:autocrypt; bh=TvK9ixWwRei4oCEeYPKW9uWdDzojNqzJFZHBSy8S3W0=; b=0IzuDVqN9K4MgCv9kAMVpxGhM7rgfTOsV+giY2sHFmdIG9TPjv/zYxUsoJDU0jsQkdE0FW 3nwow3eMQLvoKpAg== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1757055481; 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:autocrypt:autocrypt; bh=TvK9ixWwRei4oCEeYPKW9uWdDzojNqzJFZHBSy8S3W0=; b=y8z22so3t/LCPlVSsXuM4LY9tNaUh5bXHnsvWbMk+++SMpnxNiV0jh2PkM2xRdiMVVgWRM fjhdyHbrnbswMmoOgZvWmod1KYfcJ/MLcbWyfDyK3ch+XjDanm19thfdhk7SjBnIhZ15qi 7C+UfHVOwxuAdwpPrQnvCMGXZgFz1ao= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1757055481; 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:autocrypt:autocrypt; bh=TvK9ixWwRei4oCEeYPKW9uWdDzojNqzJFZHBSy8S3W0=; b=0IzuDVqN9K4MgCv9kAMVpxGhM7rgfTOsV+giY2sHFmdIG9TPjv/zYxUsoJDU0jsQkdE0FW 3nwow3eMQLvoKpAg== Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id EB2CE139B9; Fri, 5 Sep 2025 06:58:00 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id Rh+/OPiJumggfgAAD6G6ig (envelope-from ); Fri, 05 Sep 2025 06:58:00 +0000 Message-ID: Date: Fri, 5 Sep 2025 08:58:00 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 0/2] rust: zpool: add abstraction for zpool drivers To: Vitaly Wool , Johannes Weiner Cc: rust-for-linux , LKML , Uladzislau Rezki , Danilo Krummrich , Alice Ryhl , Lorenzo Stoakes , "Liam R . Howlett" , Miguel Ojeda , Alex Gaynor , Boqun Feng , Gary Guo , Bjorn Roy Baron , Benno Lossin , Andreas Hindborg , Trevor Gross , Yosry Ahmed , Nhat Pham , linux-mm@kvack.org References: <20250823130420.867133-1-vitaly.wool@konsulko.se> <20250826124454.GA1502@cmpxchg.org> Content-Language: en-US From: Vlastimil Babka Autocrypt: addr=vbabka@suse.cz; keydata= xsFNBFZdmxYBEADsw/SiUSjB0dM+vSh95UkgcHjzEVBlby/Fg+g42O7LAEkCYXi/vvq31JTB KxRWDHX0R2tgpFDXHnzZcQywawu8eSq0LxzxFNYMvtB7sV1pxYwej2qx9B75qW2plBs+7+YB 87tMFA+u+L4Z5xAzIimfLD5EKC56kJ1CsXlM8S/LHcmdD9Ctkn3trYDNnat0eoAcfPIP2OZ+ 9oe9IF/R28zmh0ifLXyJQQz5ofdj4bPf8ecEW0rhcqHfTD8k4yK0xxt3xW+6Exqp9n9bydiy tcSAw/TahjW6yrA+6JhSBv1v2tIm+itQc073zjSX8OFL51qQVzRFr7H2UQG33lw2QrvHRXqD Ot7ViKam7v0Ho9wEWiQOOZlHItOOXFphWb2yq3nzrKe45oWoSgkxKb97MVsQ+q2SYjJRBBH4 8qKhphADYxkIP6yut/eaj9ImvRUZZRi0DTc8xfnvHGTjKbJzC2xpFcY0DQbZzuwsIZ8OPJCc LM4S7mT25NE5kUTG/TKQCk922vRdGVMoLA7dIQrgXnRXtyT61sg8PG4wcfOnuWf8577aXP1x 6mzw3/jh3F+oSBHb/GcLC7mvWreJifUL2gEdssGfXhGWBo6zLS3qhgtwjay0Jl+kza1lo+Cv BB2T79D4WGdDuVa4eOrQ02TxqGN7G0Biz5ZLRSFzQSQwLn8fbwARAQABzSBWbGFzdGltaWwg QmFia2EgPHZiYWJrYUBzdXNlLmN6PsLBlAQTAQoAPgIbAwULCQgHAwUVCgkICwUWAgMBAAIe AQIXgBYhBKlA1DSZLC6OmRA9UCJPp+fMgqZkBQJnyBr8BQka0IFQAAoJECJPp+fMgqZkqmMQ AIbGN95ptUMUvo6aAdhxaOCHXp1DfIBuIOK/zpx8ylY4pOwu3GRe4dQ8u4XS9gaZ96Gj4bC+ jwWcSmn+TjtKW3rH1dRKopvC07tSJIGGVyw7ieV/5cbFffA8NL0ILowzVg8w1ipnz1VTkWDr 2zcfslxJsJ6vhXw5/npcY0ldeC1E8f6UUoa4eyoskd70vO0wOAoGd02ZkJoox3F5ODM0kjHu Y97VLOa3GG66lh+ZEelVZEujHfKceCw9G3PMvEzyLFbXvSOigZQMdKzQ8D/OChwqig8wFBmV QCPS4yDdmZP3oeDHRjJ9jvMUKoYODiNKsl2F+xXwyRM2qoKRqFlhCn4usVd1+wmv9iLV8nPs 2Db1ZIa49fJet3Sk3PN4bV1rAPuWvtbuTBN39Q/6MgkLTYHb84HyFKw14Rqe5YorrBLbF3rl M51Dpf6Egu1yTJDHCTEwePWug4XI11FT8lK0LNnHNpbhTCYRjX73iWOnFraJNcURld1jL1nV r/LRD+/e2gNtSTPK0Qkon6HcOBZnxRoqtazTU6YQRmGlT0v+rukj/cn5sToYibWLn+RoV1CE Qj6tApOiHBkpEsCzHGu+iDQ1WT0Idtdynst738f/uCeCMkdRu4WMZjteQaqvARFwCy3P/jpK uvzMtves5HvZw33ZwOtMCgbpce00DaET4y/UzsBNBFsZNTUBCACfQfpSsWJZyi+SHoRdVyX5 J6rI7okc4+b571a7RXD5UhS9dlVRVVAtrU9ANSLqPTQKGVxHrqD39XSw8hxK61pw8p90pg4G /N3iuWEvyt+t0SxDDkClnGsDyRhlUyEWYFEoBrrCizbmahOUwqkJbNMfzj5Y7n7OIJOxNRkB IBOjPdF26dMP69BwePQao1M8Acrrex9sAHYjQGyVmReRjVEtv9iG4DoTsnIR3amKVk6si4Ea X/mrapJqSCcBUVYUFH8M7bsm4CSxier5ofy8jTEa/CfvkqpKThTMCQPNZKY7hke5qEq1CBk2 wxhX48ZrJEFf1v3NuV3OimgsF2odzieNABEBAAHCwXwEGAEKACYCGwwWIQSpQNQ0mSwujpkQ PVAiT6fnzIKmZAUCZ8gcVAUJFhTonwAKCRAiT6fnzIKmZLY8D/9uo3Ut9yi2YCuASWxr7QQZ lJCViArjymbxYB5NdOeC50/0gnhK4pgdHlE2MdwF6o34x7TPFGpjNFvycZqccSQPJ/gibwNA zx3q9vJT4Vw+YbiyS53iSBLXMweeVV1Jd9IjAoL+EqB0cbxoFXvnjkvP1foiiF5r73jCd4PR rD+GoX5BZ7AZmFYmuJYBm28STM2NA6LhT0X+2su16f/HtummENKcMwom0hNu3MBNPUOrujtW khQrWcJNAAsy4yMoJ2Lw51T/5X5Hc7jQ9da9fyqu+phqlVtn70qpPvgWy4HRhr25fCAEXZDp xG4RNmTm+pqorHOqhBkI7wA7P/nyPo7ZEc3L+ZkQ37u0nlOyrjbNUniPGxPxv1imVq8IyycG AN5FaFxtiELK22gvudghLJaDiRBhn8/AhXc642/Z/yIpizE2xG4KU4AXzb6C+o7LX/WmmsWP Ly6jamSg6tvrdo4/e87lUedEqCtrp2o1xpn5zongf6cQkaLZKQcBQnPmgHO5OG8+50u88D9I rywqgzTUhHFKKF6/9L/lYtrNcHU8Z6Y4Ju/MLUiNYkmtrGIMnkjKCiRqlRrZE/v5YFHbayRD dJKXobXTtCBYpLJM4ZYRpGZXne/FAtWNe4KbNJJqxMvrTOrnIatPj8NhBVI0RSJRsbilh6TE m6M14QORSWTLRg== In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Action: no action X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: 243B9C000D X-Stat-Signature: 4j76qf7w5dhxj9fqkytz8numw4w5sedt X-Rspam-User: X-HE-Tag: 1757055482-968963 X-HE-Meta: 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 fL99dS4b k5xLamtbgKIgd3SmGV9cT1Tt0x6hPRZe2EyK1ZUwYaoJfUgXKLnULELnIE/KD1dG5dQu0i+bLOXimuKHFhW/Igv7kUIo2v7TCj0LAQ+mtMFrutmSwXwLmYjmIkCJyoKliqjDbuYR1X1B8JhlyWOgmgJYBJu82QYtMF0IH8viFa0uoRF2Q1tRBVwv5trC71x6jYXIwdvvz/78y+68lNlxFWCU/j7blJsEdMlzNn33W3k+0UoQw6ZXGLJOOeR4HXef7nxsxOozqxyITdFcPAA4X8fbHCGmxI6OJaIJRTz4HD1V99SwSq74SvwVxzO1F2Y6hOga6u3hipio/ZKV7weBM2khCIUbk5WEFJfLlZuW0BaOIHP7WvxWPoY+NTM5WYjFPKteX8WHVIQs8vYK1PWNsFc71sbhyukOZqwriDEZyK17KVj+sFl13msHO5WINUrfhrRLN X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 8/26/25 16:56, Vitaly Wool wrote: > > >> On Aug 26, 2025, at 2:44 PM, Johannes Weiner wrote: >> >> On Sat, Aug 23, 2025 at 03:04:19PM +0200, Vitaly Wool wrote: >>> Zpool is a common frontend for memory storage pool implementations. >>> These pools are typically used to store compressed memory objects, >>> e. g. for Zswap, the lightweight compressed cache for swap pages. >>> >>> This patch provides the interface to use Zpool in Rust kernel code, >>> thus enabling Rust implementations of Zpool allocators for Zswap. >> >> The zpool indirection is on its way out. >> >> When you submitted an alternate allocator backend recently, the >> resounding feedback from the zswap maintainers was that improvements >> should happen to zsmalloc incrementally. It is a lot of code and has a >> lot of features that go beyond allocation strategy. We do not want to >> fork it and fragment this space again with niche, incomplete backends. >> >> It's frustrating that you not only ignored this, but then went ahead >> and made other people invest their time and effort into this as well. >> > > I don’t think we have a consensus on that. > > And zblock is, after some additional improvements, just better than > zsmalloc in all meaningful aspects, let alone the simplicity. It is fas > easier to implement in Rust than zsmalloc, too. Besides, zram is a good > candidate to be rewritten in Rust as well and after that is done, zblock If your target is zram (not zswap) then I don't understand why insist on the zpool layer, as zram refused to adopt it in the first place? > will be even safer and faster. So while not being “incomplete", it’s > zsmalloc that is becoming a niche backend moving forward, and I would > argue that it could make more sense to eventually obsolete *it* rather > than the zpool API. > > ~Vitaly