From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.zytor.com (terminus.zytor.com [198.137.202.136]) (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 A1C57146D5A; Sat, 27 Jun 2026 01:36:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.136 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782524217; cv=none; b=GG3z24Y8jgsaEmL9lYxfbBnRYAZD4n4SQRWf8IYId9y5KnjeR7XAwCxAugYOix5PKG7+2kD7fK2emsExyso5+NN8DNDEKnUURHaOtezhINYZSpFWf1sB+eZCBmIov3A9VzpO/Zx5mu6T4M+A2U2BKrl+1U2i/6PHFTXG9YN0Qgk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782524217; c=relaxed/simple; bh=vlFmuIXNikKGJcM/rV+RwQGeISv45Ze+30sLXQvpSug=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=szZyCKuy/+bRIchGnwD3bXDx7kkZ4Y4QSSXOTc2F+K7GA7xscXv0EVxgIMIh1APr7aBDTmwpzRlAETlSak9PqVgwXLzV9UNJfNB4l10yBKHCC6POVMGoCqj6ime4K2WtlAZrIsHj4E3i9yBShpAEI5DJOoB+1C+JUoUzqZ3k1w4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com; spf=pass smtp.mailfrom=zytor.com; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b=qMyBFc1g; arc=none smtp.client-ip=198.137.202.136 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=zytor.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b="qMyBFc1g" Received: from [IPV6:2601:646:8081:7da1:dcd4:e1f8:5d79:bdb4] ([IPv6:2601:646:8081:7da1:dcd4:e1f8:5d79:bdb4]) (authenticated bits=0) by mail.zytor.com (8.18.1/8.17.1) with ESMTPSA id 65R0qN0N2285168 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NO); Fri, 26 Jun 2026 17:52:24 -0700 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 65R0qN0N2285168 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2026052701; t=1782521550; bh=CoKSivJMaQDV2sSkRTRw7olGkcZfQ72Xwmih/Aa0td0=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=qMyBFc1gnGXRksBwsJ1/rUznZgiE7lPuLPv/lWpmOM+5Q3Fqu1GkBtPV/i01hTsmm FyrrwODPBIMXlAoyCpEVfCiClmUhwPWsNagz78j3LDMf+Ut0XXJAAidVe9l1aTOAut 7WQuEQASgzET2NWeiLHKYC5brvZfsPACaGhvlYNW5X1iG8c+02aTJiS4yaJSFbtRty RzVpKhz70FSqCBKm8TK2gLW8sDPukFdgs1lqJ60AGqtpglwDIA/PnerR6f0L+dvu0f tzL0aZnBm0Ed9q+Fj1E4zhVGr5LPAVMhZk4GFV4YP0Rst/9nwzTfe9CuWNPpW58FjU Q8Foj51/YA5sw== Message-ID: <7d8efc7c-65e3-49f8-9381-910de7affef2@zytor.com> Date: Fri, 26 Jun 2026 17:52:18 -0700 Precedence: bulk X-Mailing-List: linux-raid@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: cleanup the RAID6 P/Q library v3 To: Christoph Hellwig , Andrew Morton Cc: Catalin Marinas , Will Deacon , Ard Biesheuvel , 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 , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, Herbert Xu , Dan Williams , Chris Mason , David Sterba , Arnd Bergmann , Song Liu , Yu Kuai , Li Nan , 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, linux-crypto@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-arch@vger.kernel.org, linux-raid@vger.kernel.org References: <20260518051804.462141-1-hch@lst.de> <20260518141205.c100f76eec5f58e78bbbf7af@linux-foundation.org> <20260519082432.GA14956@lst.de> Content-Language: en-US, sv-SE From: "H. Peter Anvin" In-Reply-To: <20260519082432.GA14956@lst.de> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 2026-05-19 01:24, Christoph Hellwig wrote: > > raid6: rework registration of optimized algorithms > > - avx2 instead of avx512 is probably the right thing for no > benchmarking, but if it was intentional (it wasn't), that should > be document. So I'll just switch back to the previous version to > keep the state of the art It is unlikely to be the right thing *going forward*, though. The very unfortunate performance inversion is likely model-specific. It is one of those things where you largely would have to have a list of quirks :( -hpa