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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C90E0EDA68D for ; Tue, 3 Mar 2026 16:11:56 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [127.0.0.1]) by lists.ozlabs.org (Postfix) with ESMTP id 4fQLQz2vMqz3cC6; Wed, 04 Mar 2026 03:11:55 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; arc=none smtp.remote-ip=213.95.11.211 ARC-Seal: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1772554315; cv=none; b=PZDQJ5Gs/0FL2Nh9ewXHY1P8/Ut4P3nbl6qyTDTH4+2hVvB4gOx2kvJyqyfUsqo6YFZeIuCHWasMokJSUywHdDlTn4617baRaaVNdcQ7LvM/a4iQ1r3BnqB4dWsZTJJ8v6IdjDmjLlGoWG+nBfDAt/C6Ick6IbZbdxSYSTSrPt/sLCh31u/zOuAI7otHK5J9iCIEV7qqXwhUgwexu0jmtkHnKgnrkT+184eOQmBmxXb0LlvVL+6Sw2zNhzwSVLUJvff+g39WKziTOQKgpDRI5Zp5bu/15Ek2qQNGY1wgY49HuN0w7rnleVFNx68a8nlPYRI42aWGT4fv/RWHQeceSQ== ARC-Message-Signature: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1772554315; c=relaxed/relaxed; bh=oN/fEll4fZvv2uEfMJ3TecbdzRhyRWVxsV4r7G2PpRY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=f8TCQZhPuO8QfS8J6sgKC9WtFFnx5fplwTmPl/MjHnPDYv/63Lhlp9SeX5l5IIYXp8+C6N5jUhwTZr1eRUwkydNOAIfkpHRVpOF2u33Qno01sPgYdjilVPkNZpHrW+e4s5/tuFB9muPCYK039PVjkTloxhgVn6XVIWlJDcxumL7CN6gENT0NWDiNfLTOwwpbIAtf54m6K8wRy+PM1k8oCE13N8PwZeLcOjoF1cg7OqdtfFqaKLSkF2xXu/Chk6P/hnRemQb2jKt1LVeDa+e1rrLALBfo6czh4YLPpLmRXnUHdqspmxYFVDGcOWKxB49g7Cd84mOkBsZAHqOFT6959w== ARC-Authentication-Results: i=1; lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=lst.de; spf=pass (client-ip=213.95.11.211; helo=verein.lst.de; envelope-from=hch@lst.de; receiver=lists.ozlabs.org) smtp.mailfrom=lst.de Authentication-Results: lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=lst.de Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lst.de (client-ip=213.95.11.211; helo=verein.lst.de; envelope-from=hch@lst.de; receiver=lists.ozlabs.org) 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 lists.ozlabs.org (Postfix) with ESMTPS id 4fQLQx2k3Vz3c9y for ; Wed, 04 Mar 2026 03:11:53 +1100 (AEDT) Received: by verein.lst.de (Postfix, from userid 2407) id E4C7E68BEB; Tue, 3 Mar 2026 17:11:45 +0100 (CET) Date: Tue, 3 Mar 2026 17:11:45 +0100 From: Christoph Hellwig To: Eric Biggers Cc: Christoph Hellwig , Andrew Morton , Richard Henderson , Matt Turner , Magnus Lindholm , Russell King , Catalin Marinas , Will Deacon , Huacai Chen , WANG Xuerui , Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , "Christophe Leroy (CS GROUP)" , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , "David S. Miller" , Andreas Larsson , Richard Weinberger , Anton Ivanov , Johannes Berg , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Herbert Xu , Dan Williams , Chris Mason , David Sterba , Arnd Bergmann , Song Liu , Yu Kuai , Li Nan , linux-alpha@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, loongarch@lists.linux.dev, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org, linux-crypto@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-arch@vger.kernel.org, linux-raid@vger.kernel.org Subject: Re: cleanup the RAID5 XOR library Message-ID: <20260303161145.GK7021@lst.de> References: <20260226151106.144735-1-hch@lst.de> <20260228073553.GL65277@quark> X-Mailing-List: linuxppc-dev@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Archive: , List-Subscribe: , , List-Unsubscribe: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260228073553.GL65277@quark> User-Agent: Mutt/1.5.17 (2007-11-01) On Fri, Feb 27, 2026 at 11:35:53PM -0800, Eric Biggers wrote: > > https://git.infradead.org/?p=users/hch/misc.git;a=shortlog;h=refs/heads/xor-improvements > > Overall this looks great. xor_gen() really needs a KUnit test, though. > Without that, how was this tested? fio data integrity testing on degraded raid. But yes, a unit test would be nice. > Later we should remove some of the obsolete implementations, such as the > alpha or x86 MMX ones. Those platforms have no optimized code in > lib/crc/ or lib/crypto/, and I doubt anyone cares. I'd rather leave that to the architecture maintainers, but overall I ahree. > Also, I notice that no one has optimized this for the latest x86_64 CPUs > by using the vpternlogd instruction to do 3-input XORs. That would be > another good future project. Yes, as would rewriting the routines to deal with more than 4 + 1 stripes as that is a really narrow raid these days.