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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 5EA3DC433DB for ; Wed, 20 Jan 2021 17:59:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 222BF223E0 for ; Wed, 20 Jan 2021 17:59:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391280AbhATR6w (ORCPT ); Wed, 20 Jan 2021 12:58:52 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40992 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728756AbhATRzl (ORCPT ); Wed, 20 Jan 2021 12:55:41 -0500 Received: from merlin.infradead.org (merlin.infradead.org [IPv6:2001:8b0:10b:1231::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 13D6DC0613D6 for ; Wed, 20 Jan 2021 09:54:48 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=j8X2B6e/nyEs+NJNeqzCnZuwySVRnniHinpf7QdycqQ=; b=fC3BZkihHPF+tMwceR6naiiutb qfz3Rgpz8x00bj6HuZY4vYB+2Ky1eg90RSTKTqC5EN5BYOjGcKbS/pduZQaG3Dm6LRvopmu+rsW7Y Elvz0OqATEMrsGzfgPpDisuuWQ5N84JbRO4Ah4TDK+rwFS29SGF1ycchknpeClgNvhcdQG//3yMOZ fDyAd3eoOXRswOHJH3AxZO3Y8kk6YjX5x5elSMD5NbHf3L81fYh88QmtS8pEXgjXEUph5Xq7REuL/ 0zbGTjZwbp6Z6NPRKpfa5751LNBxdR1G7ERvMmThR2bl4U5kiT4sUWwTyFCMQhMicuyYdwarRX8Qi 67DXD6Ng==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1l2Hgr-0002It-1h; Wed, 20 Jan 2021 17:54:45 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id D6414303271; Wed, 20 Jan 2021 18:54:43 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id CB0D120BCCFD7; Wed, 20 Jan 2021 18:54:43 +0100 (CET) Date: Wed, 20 Jan 2021 18:54:43 +0100 From: Peter Zijlstra To: vincent.donnefort@arm.com Cc: tglx@linutronix.de, linux-kernel@vger.kernel.org, valentin.schneider@arm.com Subject: Re: [PATCH 3/4] cpu/hotplug: Add cpuhp_invoke_callback_range() Message-ID: References: <1610385047-92151-1-git-send-email-vincent.donnefort@arm.com> <1610385047-92151-4-git-send-email-vincent.donnefort@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 20, 2021 at 02:11:14PM +0100, Peter Zijlstra wrote: > On Mon, Jan 11, 2021 at 05:10:46PM +0000, vincent.donnefort@arm.com wrote: > > @@ -157,26 +162,24 @@ static int cpuhp_invoke_callback(unsigned int cpu, enum cpuhp_state state, > > > > if (st->fail == state) { > > st->fail = CPUHP_INVALID; > > - > > - if (!(bringup ? step->startup.single : step->teardown.single)) > > - return 0; > > - > > return -EAGAIN; > > } > > > > + if (cpuhp_step_empty(bringup, step)) { > > + WARN_ON_ONCE(1); > > + return 0; > > + } > > This changes the behaviour of fail.. might be best to refactor without > changing behaviour. > Aah, the trick is in cpuhp_next_state() skipping empty states, so we'll never get there.