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 X-Spam-Level: X-Spam-Status: No, score=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0E663C4338F for ; Wed, 18 Aug 2021 13:46:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F1061610C7 for ; Wed, 18 Aug 2021 13:46:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238489AbhHRNq7 (ORCPT ); Wed, 18 Aug 2021 09:46:59 -0400 Received: from bilbo.ozlabs.org ([203.11.71.1]:42241 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237528AbhHRNqj (ORCPT ); Wed, 18 Aug 2021 09:46:39 -0400 Received: by ozlabs.org (Postfix, from userid 1034) id 4GqTgv17vGz9sVw; Wed, 18 Aug 2021 23:46:02 +1000 (AEST) From: Michael Ellerman To: paulus@samba.org, benh@kernel.crashing.org, mpe@ellerman.id.au, Laurent Dufour Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, nathanl@linux.ibm.com In-Reply-To: <20210429174908.16613-1-ldufour@linux.ibm.com> References: <20210429174908.16613-1-ldufour@linux.ibm.com> Subject: Re: [PATCH v5] pseries: prevent free CPU ids to be reused on another node Message-Id: <162929391998.3619265.3392197710789152359.b4-ty@ellerman.id.au> Date: Wed, 18 Aug 2021 23:38:39 +1000 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 29 Apr 2021 19:49:08 +0200, Laurent Dufour wrote: > When a CPU is hot added, the CPU ids are taken from the available mask from > the lower possible set. If that set of values was previously used for CPU > attached to a different node, this seems to application like if these CPUs > have migrated from a node to another one which is not expected in real > life. > > To prevent this, it is needed to record the CPU ids used for each node and > to not reuse them on another node. However, to prevent CPU hot plug to > fail, in the case the CPU ids is starved on a node, the capability to reuse > other nodes’ free CPU ids is kept. A warning is displayed in such a case > to warn the user. > > [...] Applied to powerpc/next. [1/1] pseries: prevent free CPU ids to be reused on another node https://git.kernel.org/powerpc/c/bd1dd4c5f5286df0148b5b316f37c583b8f55fa1 cheers