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=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,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 06142C3A5A6 for ; Thu, 19 Sep 2019 10:59:38 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id B1341217D6 for ; Thu, 19 Sep 2019 10:59:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B1341217D6 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 46Yv4Q2pGjzF3xJ for ; Thu, 19 Sep 2019 20:59:34 +1000 (AEST) Received: from ozlabs.org (bilbo.ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 46YtKh0TPwzF4YP for ; Thu, 19 Sep 2019 20:26:00 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Received: by ozlabs.org (Postfix, from userid 1034) id 46YtKd0lYzz9sPf; Thu, 19 Sep 2019 20:25:56 +1000 (AEST) X-powerpc-patch-notification: thanks X-powerpc-patch-commit: 92c94dfb69e350471473fd3075c74bc68150879e In-Reply-To: <20190910225244.25056-1-nathanl@linux.ibm.com> To: Nathan Lynch , linuxppc-dev@lists.ozlabs.org From: Michael Ellerman Subject: Re: [PATCH] powerpc/pseries: correctly track irq state in default idle Message-Id: <46YtKd0lYzz9sPf@ozlabs.org> Date: Thu, 19 Sep 2019 20:25:56 +1000 (AEST) X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: ego@linux.vnet.ibm.com, npiggin@gmail.com Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Tue, 2019-09-10 at 22:52:44 UTC, Nathan Lynch wrote: > prep_irq_for_idle() is intended to be called before entering > H_CEDE (and it is used by the pseries cpuidle driver). However the > default pseries idle routine does not call it, leading to mismanaged > lazy irq state when the cpuidle driver isn't in use. Manifestations of > this include: > > * Dropped IPIs in the time immediately after a cpu comes > online (before it has installed the cpuidle handler), making the > online operation block indefinitely waiting for the new cpu to > respond. > > * Hitting this WARN_ON in arch_local_irq_restore(): > /* > * We should already be hard disabled here. We had bugs > * where that wasn't the case so let's dbl check it and > * warn if we are wrong. Only do that when IRQ tracing > * is enabled as mfmsr() can be costly. > */ > if (WARN_ON_ONCE(mfmsr() & MSR_EE)) > __hard_irq_disable(); > > Call prep_irq_for_idle() from pseries_lpar_idle() and honor its > result. > > Fixes: 363edbe2614a ("powerpc: Default arch idle could cede processor on pseries") > Signed-off-by: Nathan Lynch Applied to powerpc next, thanks. https://git.kernel.org/powerpc/c/92c94dfb69e350471473fd3075c74bc68150879e cheers