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=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no 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 4041FC4363D for ; Tue, 6 Oct 2020 21:26:30 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) (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 8F89C20897 for ; Tue, 6 Oct 2020 21:26:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="cFZqIT7f"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="icOFZZbq" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8F89C20897 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linutronix.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id 1295185E09; Tue, 6 Oct 2020 21:26:29 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id uSShsXPruLZj; Tue, 6 Oct 2020 21:26:28 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by fraxinus.osuosl.org (Postfix) with ESMTP id 8721985DC0; Tue, 6 Oct 2020 21:26:28 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 6DF81C016F; Tue, 6 Oct 2020 21:26:28 +0000 (UTC) Received: from silver.osuosl.org (smtp3.osuosl.org [140.211.166.136]) by lists.linuxfoundation.org (Postfix) with ESMTP id A8772C0051 for ; Tue, 6 Oct 2020 21:26:27 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by silver.osuosl.org (Postfix) with ESMTP id 864612153E for ; Tue, 6 Oct 2020 21:26:27 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from silver.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id ucY1LDmNPh1h for ; Tue, 6 Oct 2020 21:26:24 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by silver.osuosl.org (Postfix) with ESMTPS id 68842207A1 for ; Tue, 6 Oct 2020 21:26:24 +0000 (UTC) From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1602019582; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=9tgJmD3H+kQvwmmqg/DvlciSq+QY0pyLjKsrBXUuu/A=; b=cFZqIT7fnWiav7/ztiQ2eAZrNezy6ROUKWOKBglQIHXDFoiq3KUUqCJCc5Wp39X9/Eg/h+ 6DlYgVyjN9FUH/Z/swKRJ1r9WHK9/Wat8PDyz7jVThsRanPge08+fbZnY5oRymbD0eP6LT GsTabN4RzNPO0qgLhRxj8CmGRqE9UfFtO/PefUZd0Zis2ykaWtmw7jeg/rJEisMmQ726XB wHaOtOeTMSTZZD/TiVsJZGOGS8qcn/VaFUWw7A1ns2jX5CHxYeLPonhKtSMFIbgTUSP4fZ FTk2JISn0dEb5Ni3gQJz9230XCZuzW8A21AOyPT5rCiS+K4ngwGaMp28rWdfCg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1602019582; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=9tgJmD3H+kQvwmmqg/DvlciSq+QY0pyLjKsrBXUuu/A=; b=icOFZZbqoBxXqalrREJjpN5TJ4yXrK7d43bToBL6O7AO9brurovFGjOxPaxYzqSMXBxJMR QbIvBKtz5ojRUsBQ== To: David Woodhouse , x86@kernel.org Subject: Re: [PATCH 07/13] irqdomain: Add max_affinity argument to irq_domain_alloc_descs() In-Reply-To: <20201005152856.974112-7-dwmw2@infradead.org> References: <77e64f977f559412f62b467fd062d051ea288f14.camel@infradead.org> <20201005152856.974112-1-dwmw2@infradead.org> <20201005152856.974112-7-dwmw2@infradead.org> Date: Tue, 06 Oct 2020 23:26:22 +0200 Message-ID: <87lfgj59mp.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Cc: Paolo Bonzini , iommu , linux-hyperv@vger.kernel.org, kvm X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On Mon, Oct 05 2020 at 16:28, David Woodhouse wrote: > From: David Woodhouse > > This is the maximum possible set of CPUs which can be used. Use it > to calculate the default affinity requested from __irq_alloc_descs() > by first attempting to find the intersection with irq_default_affinity, > or falling back to using just the max_affinity if the intersection > would be empty. And why do we need that as yet another argument? This is an optional property of the irq domain, really and no caller has any business with that. > int irq_domain_alloc_descs(int virq, unsigned int cnt, irq_hw_number_t hwirq, > - int node, const struct irq_affinity_desc *affinity) > + int node, const struct irq_affinity_desc *affinity, > + const struct cpumask *max_affinity) > { > + cpumask_var_t default_affinity; > unsigned int hint; > + int i; > + > + /* Check requested per-IRQ affinities are in the possible range */ > + if (affinity && max_affinity) { > + for (i = 0; i < cnt; i++) > + if (!cpumask_subset(&affinity[i].mask, max_affinity)) > + return -EINVAL; https://lore.kernel.org/r/alpine.DEB.2.20.1701171956290.3645@nanos What is preventing the affinity spreading code from spreading the masks out to unusable CPUs? The changelog is silent about that part. > + /* > + * Generate default affinity. Either the possible subset of > + * irq_default_affinity if such a subset is non-empty, or fall > + * back to the provided max_affinity if there is no intersection. .. > + * And just a copy of irq_default_affinity in the > + * !CONFIG_CPUMASK_OFFSTACK case. We know that already... > + */ > + memset(&default_affinity, 0, sizeof(default_affinity)); Right, memset() before allocating is useful. > + if ((max_affinity && > + !cpumask_subset(irq_default_affinity, max_affinity))) { > + if (!alloc_cpumask_var(&default_affinity, GFP_KERNEL)) > + return -ENOMEM; > + cpumask_and(default_affinity, max_affinity, > + irq_default_affinity); > + if (cpumask_empty(default_affinity)) > + cpumask_copy(default_affinity, max_affinity); > + } else if (cpumask_available(default_affinity)) > + cpumask_copy(default_affinity, irq_default_affinity); That's garbage and unreadable. Thanks, tglx _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu