From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from shelob.surriel.com (shelob.surriel.com [96.67.55.147]) (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 7AC3B23C8D9 for ; Fri, 7 Feb 2025 17:47:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=96.67.55.147 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738950480; cv=none; b=fFrnjhXAbrrqNV8g/2SnNAiVcPXv0VTX3DU75NN4nKnD9MDA6SqGzWw7kdi7SdGTeaM+4eCYVyrDFFingQ9DzpYmVqcWoUHQ93Gil5/bTk/oyuAasA3YS/BijrRVP/AsMkvgZ4AyYlDoD4uOyfQcKtsIRJ9luzpUrWMRRVgAdUs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738950480; c=relaxed/simple; bh=X8vLtEFCqpioyxyUoF5BAw9f0a1GinJmIHMGzx54B+g=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=KI7twfHvQx0+bXehhKXot9LmOuGuLHPoL08RAq9gtY5bcA6m7MMRBMjAzGwOpsl4Z06OVah9ovklO2atn+6+ojzmZ7ToB64LgSJR3k2G19pURhcPaMX8krMn90R5ugz4NBEerMoezVpOp3CjPHoHOVFfL43CNzhw3bwR9LV3svU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=surriel.com; spf=pass smtp.mailfrom=shelob.surriel.com; arc=none smtp.client-ip=96.67.55.147 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=surriel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=shelob.surriel.com Received: from fangorn.home.surriel.com ([10.0.13.7]) by shelob.surriel.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.97.1) (envelope-from ) id 1tgSRK-000000000iv-3IAC; Fri, 07 Feb 2025 12:46:54 -0500 Message-ID: Subject: Re: [PATCH v9 00/12] AMD broadcast TLB invalidation From: Rik van Riel To: Peter Zijlstra Cc: Oleksandr Natalenko , x86@kernel.org, linux-kernel@vger.kernel.org, bp@alien8.de, dave.hansen@linux.intel.com, zhengqi.arch@bytedance.com, nadav.amit@gmail.com, thomas.lendacky@amd.com, kernel-team@meta.com, linux-mm@kvack.org, akpm@linux-foundation.org, jannh@google.com, mhklinux@outlook.com, andrew.cooper3@citrix.com Date: Fri, 07 Feb 2025 12:46:54 -0500 In-Reply-To: <20250207081629.GT7145@noisy.programming.kicks-ass.net> References: <20250206044346.3810242-1-riel@surriel.com> <12602226.O9o76ZdvQC@natalenko.name> <8111558b52cec1152746b05a9c1d657d18df0fe2.camel@surriel.com> <20250206142308.GR7145@noisy.programming.kicks-ass.net> <20250207081629.GT7145@noisy.programming.kicks-ass.net> Autocrypt: addr=riel@surriel.com; prefer-encrypt=mutual; keydata=mQENBFIt3aUBCADCK0LicyCYyMa0E1lodCDUBf6G+6C5UXKG1jEYwQu49cc/gUBTTk33A eo2hjn4JinVaPF3zfZprnKMEGGv4dHvEOCPWiNhlz5RtqH3SKJllq2dpeMS9RqbMvDA36rlJIIo47 Z/nl6IA8MDhSqyqdnTY8z7LnQHqq16jAqwo7Ll9qALXz4yG1ZdSCmo80VPetBZZPw7WMjo+1hByv/ lvdFnLfiQ52tayuuC1r9x2qZ/SYWd2M4p/f5CLmvG9UcnkbYFsKWz8bwOBWKg1PQcaYHLx06sHGdY dIDaeVvkIfMFwAprSo5EFU+aes2VB2ZjugOTbkkW2aPSWTRsBhPHhV6dABEBAAG0HlJpayB2YW4gU mllbCA8cmllbEByZWRoYXQuY29tPokBHwQwAQIACQUCW5LcVgIdIAAKCRDOed6ShMTeg05SB/986o gEgdq4byrtaBQKFg5LWfd8e+h+QzLOg/T8mSS3dJzFXe5JBOfvYg7Bj47xXi9I5sM+I9Lu9+1XVb/ r2rGJrU1DwA09TnmyFtK76bgMF0sBEh1ECILYNQTEIemzNFwOWLZZlEhZFRJsZyX+mtEp/WQIygHV WjwuP69VJw+fPQvLOGn4j8W9QXuvhha7u1QJ7mYx4dLGHrZlHdwDsqpvWsW+3rsIqs1BBe5/Itz9o 6y9gLNtQzwmSDioV8KhF85VmYInslhv5tUtMEppfdTLyX4SUKh8ftNIVmH9mXyRCZclSoa6IMd635 Jq1Pj2/Lp64tOzSvN5Y9zaiCc5FucXtB9SaWsgdmFuIFJpZWwgPHJpZWxAc3VycmllbC5jb20+iQE +BBMBAgAoBQJSLd2lAhsjBQkSzAMABgsJCAcDAgYVCAIJCgsEFgIDAQIeAQIXgAAKCRDOed6ShMTe g4PpB/0ZivKYFt0LaB22ssWUrBoeNWCP1NY/lkq2QbPhR3agLB7ZXI97PF2z/5QD9Fuy/FD/jddPx KRTvFCtHcEzTOcFjBmf52uqgt3U40H9GM++0IM0yHusd9EzlaWsbp09vsAV2DwdqS69x9RPbvE/Ne fO5subhocH76okcF/aQiQ+oj2j6LJZGBJBVigOHg+4zyzdDgKM+jp0bvDI51KQ4XfxV593OhvkS3z 3FPx0CE7l62WhWrieHyBblqvkTYgJ6dq4bsYpqxxGJOkQ47WpEUx6onH+rImWmPJbSYGhwBzTo0Mm G1Nb1qGPG+mTrSmJjDRxrwf1zjmYqQreWVSFEt26tBpSaWsgdmFuIFJpZWwgPHJpZWxAZmIuY29tP okBPgQTAQIAKAUCW5LbiAIbIwUJEswDAAYLCQgHAwIGFQgCCQoLBBYCAwECHgECF4AACgkQznneko TE3oOUEQgAsrGxjTC1bGtZyuvyQPcXclap11Ogib6rQywGYu6/Mnkbd6hbyY3wpdyQii/cas2S44N cQj8HkGv91JLVE24/Wt0gITPCH3rLVJJDGQxprHTVDs1t1RAbsbp0XTksZPCNWDGYIBo2aHDwErhI omYQ0Xluo1WBtH/UmHgirHvclsou1Ks9jyTxiPyUKRfae7GNOFiX99+ZlB27P3t8CjtSO831Ij0Ip QrfooZ21YVlUKw0Wy6Ll8EyefyrEYSh8KTm8dQj4O7xxvdg865TLeLpho5PwDRF+/mR3qi8CdGbkE c4pYZQO8UDXUN4S+pe0aTeTqlYw8rRHWF9TnvtpcNzZw== Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.54.1 (3.54.1-1.fc41) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Sender: riel@surriel.com On Fri, 2025-02-07 at 09:16 +0100, Peter Zijlstra wrote: > On Thu, Feb 06, 2025 at 09:48:25AM -0500, Rik van Riel wrote: >=20 >=20 > > we can just round up the > > end address to the nearest stride boundary > > there, with a comment explaining why? >=20 > Well, why are we rounding at all? I don't think I've seen an > explanation > for that anywhere yet. >=20 > What made you do this? The only real reason is to not end up with a 0 value for nr in these loops: for (addr =3D info->start; addr < info->end; addr +=3D nr << PAGE_SHIFT) { nr =3D min((info->end - addr) >> PAGE_SHIFT, invlpgb_count_max); invlpgb_flush_addr_nosync(addr, nr); } =20 Which makes me think we could just insert a "nr =3D max(nr, 1)" in there, and round up partial pages that way? Looking further, I already did that on the userspace flushing side. Let me do the same thing on the kernel side, and remove the other code related to partial pages being passed in. --=20 All Rights Reversed.