From mboxrd@z Thu Jan 1 00:00:00 1970 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 smtp.subspace.kernel.org (Postfix) with ESMTPS id 479764B8DC0; Tue, 3 Mar 2026 16:11:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.95.11.211 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772554315; cv=none; b=BdkCCFGpKvxK+oaqXxam0xVm2thnZEb2GCe+hIRVVWDCV7PeZyIGUKjtz6+rvPmqBE+QAaQWLZ0xjRzsY1bbpgr7VkyzCXvTqYMrmh3VBoW66z4GP1JpZKZf3PWHkJnc95jxHX1JBwaUeIuRxkRDtbI3+eJkqQiTrE1Urr5m1Sw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772554315; c=relaxed/simple; bh=qXfMFx1V+SjVZ1JKY59h8uVCQyv/ezN1YeeaK8ler8s=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=L8eCwVgG3/P02nIJ0AKUf+KgRyJmk6K+Lc7ahVIFtDojUCjQuOPP2XFCZ3buLQKWQqgDmcLpG/y1++mV42FTRlsRVmEujWN3FBMWt5PIIVUB6oZ9Sy49wXvvdO8q8Z4nlQpRATKwFLV7nvOMxc8dIP/ztNh8EUL3H4uW+zDenY8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lst.de; spf=pass smtp.mailfrom=lst.de; arc=none smtp.client-ip=213.95.11.211 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lst.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=lst.de 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> Precedence: bulk X-Mailing-List: linux-alpha@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: <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. 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 3EFE1EDA693 for ; Tue, 3 Mar 2026 16:12:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=gbnlosesOIq1rsgmrY9PAkVnB3wj5YXPU0vEtDPVmJU=; b=fJTolGjenB3+UG oqRC5nCL0XU8UYy6b+NGDyScddNW97mv+Rwn/PPsx7POPpKvQ8M8ejDblQpy+AkntWLW3pLhzzHQf FuYFNVwxaXwpbOtnnnWFu4k1j1JI+MP1pcbjY+ricAgWl47itiwNqH/oDeojwKOOLX5EzGfSF/z3r or1K/PYXZCVbiFgYW1RSmnMCcXsBbViqsclyyJkedm3cJSOzenY14rvBo/PoAaOm54e8/c+i+4bD/ bQB4jhvqGCDkVK2aSLvLWBCRgx8dIM3puFHx/3vByBdNaywpownHMggD5Hvicz+g+XMXOoNz7ME9Q +EzbT1o9TN6cTYTx5E2Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vxSLh-0000000FXCa-3yZm; Tue, 03 Mar 2026 16:11:53 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vxSLf-0000000FXBy-1URB; Tue, 03 Mar 2026 16:11:52 +0000 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> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20260228073553.GL65277@quark> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260303_081151_542429_FC2DF970 X-CRM114-Status: GOOD ( 16.88 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org 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. _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv