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 0C073C0218F for ; Fri, 31 Jan 2025 17:27:43 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [127.0.0.1]) by lists.ozlabs.org (Postfix) with ESMTP id 4Yl2s96frHz30Vk; Sat, 1 Feb 2025 04:27:41 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; arc=none smtp.remote-ip=63.228.1.57 ARC-Seal: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1738344461; cv=none; b=A05j6jG3Szb5pkurURxFGo1e308ubvDz1dlERaCb+0QFe4cVnixB2BE89sVeSyD6IrJjOUdLBpWRsGStOqfghP3yzgm8uW98j1vUywGrTfaOGwQXg5efnhC6rAq9Ob4GWvmw+mv6Hp7vlJbVIxzfKv1qqpyaZ7Irbpff/VmMb+t8EGZUZxDNnC+PA3Y8NsM8Wxrxtkw1dKTWuubt0X6rMBIsEpF3XbbndrR7V2RpEe6t+ywmFDCGovtpSbbKmxAo2D3l+TetmV+DtV5LKEUFZwdTuA2WNnhz6SXVp9avFIQXrLtahgYnekPwafaPsvcAI+qiz/2x1rhx9rWvDnJGjA== ARC-Message-Signature: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1738344461; c=relaxed/relaxed; bh=7/DAB1ks3lKI8Bq5mn4V2TLaEnA63Y1GxoZAeug6U5c=; h=Date:From:To:Cc:Subject:Message-ID:References:Mime-Version: Content-Type:Content-Disposition:In-Reply-To; b=RCjA7XJ2bQkrqqFtQzdGokaaqArbOcoqLpswBb1vFJQk5M+FWgy8QhBbDs4vD7J9KBMB9WQy0FQqrMRNTII73F8KQ6NeedIEw5jh7a/ZCL+CZfYLD/3wQWUPNvkUqQ8SdRTDH6Y53nMxr0u8YqEkrh4SwECYiLq6h9Q03YRIWT+Ba1/l/PVD9Wx58xOMIppSoHfvjdHL3MiaIHPGJAHVon3fBqXjiPSToljyf5lLNLydZIu23kR8mDHWHMV6tVJLBh7LgAolukUZ0Fvb5M50uEwrVc1EvZauNK7UoDWmd58Q0h9U9kqWjbFa7DuRR6QVINgkYpxp59QF7bk1LDq9qA== ARC-Authentication-Results: i=1; lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org; spf=pass (client-ip=63.228.1.57; helo=gate.crashing.org; envelope-from=segher@kernel.crashing.org; receiver=lists.ozlabs.org) smtp.mailfrom=kernel.crashing.org Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.crashing.org (client-ip=63.228.1.57; helo=gate.crashing.org; envelope-from=segher@kernel.crashing.org; receiver=lists.ozlabs.org) Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) by lists.ozlabs.org (Postfix) with ESMTP id 4Yl2s80FqTz30Vj for ; Sat, 1 Feb 2025 04:27:39 +1100 (AEDT) Received: from gate.crashing.org (localhost.localdomain [127.0.0.1]) by gate.crashing.org (8.14.1/8.14.1) with ESMTP id 50VHQbYS031080; Fri, 31 Jan 2025 11:26:37 -0600 Received: (from segher@localhost) by gate.crashing.org (8.14.1/8.14.1/Submit) id 50VHQaqp031078; Fri, 31 Jan 2025 11:26:36 -0600 X-Authentication-Warning: gate.crashing.org: segher set sender to segher@kernel.crashing.org using -f Date: Fri, 31 Jan 2025 11:26:36 -0600 From: Segher Boessenkool To: Paul Mackerras Cc: linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH 4/5] powerpc: Define config option for processors without broadcast TLBIE Message-ID: <20250131172636.GF20626@gate.crashing.org> References: X-Mailing-List: linuxppc-dev@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Archive: , List-Subscribe: , , List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.3i On Wed, Jan 29, 2025 at 09:53:44AM +1100, Paul Mackerras wrote: > Power ISA v3.1 implementations in the Linux Compliancy Subset and > lower are not required to implement broadcast TLBIE, and in fact > Microwatt doesn't. But this pretty much means that such systems cannot be SMP systems at all. Implementing the necessary synchronisation using some cobbled-together rickety jury-rigged contraption is not anyone's goal. Interesting that you did not see any performance loss, btw! Well you didn't try it on anything bigger than a simple dual CPU :-) Segher