From patchwork Tue Jun 29 15:27:33 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nitesh Narayan Lal X-Patchwork-Id: 1498401 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=linux-pci-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=c42bJMGn; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4GDpKJ6bmYz9sW8 for ; Wed, 30 Jun 2021 01:28:36 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234830AbhF2PbB (ORCPT ); Tue, 29 Jun 2021 11:31:01 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:58749 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234810AbhF2Pa4 (ORCPT ); Tue, 29 Jun 2021 11:30:56 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1624980509; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=v4yUPdtpOJEcweWgkTfPnmAZIWcrOmFAWUYkxKtZ/fo=; b=c42bJMGnmIVqVr/O8sl/nEc+0LVhE6SMl7qfhKL5ZGo/GdIltZt6n+I15sVjfnjBX/gMf6 eQekNJj5zEqV4XrDjAzn/EbLwljmTSZAAA2VVqSaMhrESCEZ163r5v7rVu2g2FcV7S0Cxc Gjwi+Y913uo73XiARCEFCmTjKJHigQg= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-424-XIzoBdyXP4GXO5ynXFATzA-1; Tue, 29 Jun 2021 11:28:26 -0400 X-MC-Unique: XIzoBdyXP4GXO5ynXFATzA-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B0761100CCCA; Tue, 29 Jun 2021 15:28:21 +0000 (UTC) Received: from virtlab719.virt.lab.eng.bos.redhat.com (virtlab719.virt.lab.eng.bos.redhat.com [10.19.153.15]) by smtp.corp.redhat.com (Postfix) with ESMTP id EA9CC69CB7; Tue, 29 Jun 2021 15:28:09 +0000 (UTC) From: Nitesh Narayan Lal To: linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, intel-wired-lan@lists.osuosl.org, netdev@vger.kernel.org, linux-api@vger.kernel.org, linux-pci@vger.kernel.org, tglx@linutronix.de, jesse.brandeburg@intel.com, robin.murphy@arm.com, mtosatti@redhat.com, mingo@kernel.org, jbrandeb@kernel.org, frederic@kernel.org, juri.lelli@redhat.com, abelits@marvell.com, bhelgaas@google.com, rostedt@goodmis.org, peterz@infradead.org, davem@davemloft.net, akpm@linux-foundation.org, sfr@canb.auug.org.au, stephen@networkplumber.org, rppt@linux.vnet.ibm.com, chris.friesen@windriver.com, maz@kernel.org, nhorman@tuxdriver.com, pjwaskiewicz@gmail.com, sassmann@redhat.com, thenzl@redhat.com, kashyap.desai@broadcom.com, sumit.saxena@broadcom.com, shivasharan.srikanteshwara@broadcom.com, sathya.prakash@broadcom.com, sreekanth.reddy@broadcom.com, suganath-prabu.subramani@broadcom.com, james.smart@broadcom.com, dick.kennedy@broadcom.com, jkc@redhat.com, faisal.latif@intel.com, shiraz.saleem@intel.com, tariqt@nvidia.com, ahleihel@redhat.com, kheib@redhat.com, borisp@nvidia.com, saeedm@nvidia.com, benve@cisco.com, govind@gmx.com, jassisinghbrar@gmail.com, ajit.khaparde@broadcom.com, sriharsha.basavapatna@broadcom.com, somnath.kotur@broadcom.com, nilal@redhat.com, tatyana.e.nikolova@intel.com, mustafa.ismail@intel.com, ahs3@redhat.com, leonro@nvidia.com Subject: [PATCH v2 01/14] genirq: Provide new interfaces for affinity hints Date: Tue, 29 Jun 2021 11:27:33 -0400 Message-Id: <20210629152746.2953364-2-nitesh@redhat.com> In-Reply-To: <20210629152746.2953364-1-nitesh@redhat.com> References: <20210629152746.2953364-1-nitesh@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org From: Thomas Gleixner The discussion about removing the side effect of irq_set_affinity_hint() of actually applying the cpumask (if not NULL) as affinity to the interrupt, unearthed a few unpleasantries: 1) The modular perf drivers rely on the current behaviour for the very wrong reasons. 2) While none of the other drivers prevents user space from changing the affinity, a cursorily inspection shows that there are at least expectations in some drivers. #1 needs to be cleaned up anyway, so that's not a problem #2 might result in subtle regressions especially when irqbalanced (which nowadays ignores the affinity hint) is disabled. Provide new interfaces: irq_update_affinity_hint() - Only sets the affinity hint pointer irq_set_affinity_and_hint() - Set the pointer and apply the affinity to the interrupt Make irq_set_affinity_hint() a wrapper around irq_apply_affinity_hint() and document it to be phased out. Signed-off-by: Thomas Gleixner Signed-off-by: Nitesh Narayan Lal Link: https://lore.kernel.org/r/20210501021832.743094-1-jesse.brandeburg@intel.com --- include/linux/interrupt.h | 53 ++++++++++++++++++++++++++++++++++++++- kernel/irq/manage.c | 8 +++--- 2 files changed, 56 insertions(+), 5 deletions(-) diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index 2ed65b01c961..bd25ba029c68 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -328,7 +328,46 @@ extern int irq_force_affinity(unsigned int irq, const struct cpumask *cpumask); extern int irq_can_set_affinity(unsigned int irq); extern int irq_select_affinity(unsigned int irq); -extern int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m); +extern int __irq_apply_affinity_hint(unsigned int irq, const struct cpumask *m, + bool setaffinity); + +/** + * irq_update_affinity_hint - Update the affinity hint + * @irq: Interrupt to update + * @cpumask: cpumask pointer (NULL to clear the hint) + * + * Updates the affinity hint, but does not change the affinity of the interrupt. + */ +static inline int +irq_update_affinity_hint(unsigned int irq, const struct cpumask *m) +{ + return __irq_apply_affinity_hint(irq, m, false); +} + +/** + * irq_set_affinity_and_hint - Update the affinity hint and apply the provided + * cpumask to the interrupt + * @irq: Interrupt to update + * @cpumask: cpumask pointer (NULL to clear the hint) + * + * Updates the affinity hint and if @cpumask is not NULL it applies it as + * the affinity of that interrupt. + */ +static inline int +irq_set_affinity_and_hint(unsigned int irq, const struct cpumask *m) +{ + return __irq_apply_affinity_hint(irq, m, true); +} + +/* + * Deprecated. Use irq_update_affinity_hint() or irq_set_affinity_and_hint() + * instead. + */ +static inline int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m) +{ + return irq_set_affinity_and_hint(irq, m); +} + extern int irq_update_affinity_desc(unsigned int irq, struct irq_affinity_desc *affinity); @@ -360,6 +399,18 @@ static inline int irq_can_set_affinity(unsigned int irq) static inline int irq_select_affinity(unsigned int irq) { return 0; } +static inline int irq_update_affinity_hint(unsigned int irq, + const struct cpumask *m) +{ + return -EINVAL; +} + +static inline int irq_set_affinity_and_hint(unsigned int irq, + const struct cpumask *m) +{ + return -EINVAL; +} + static inline int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m) { diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index ef30b4762947..837b63e63111 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -487,7 +487,8 @@ int irq_force_affinity(unsigned int irq, const struct cpumask *cpumask) } EXPORT_SYMBOL_GPL(irq_force_affinity); -int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m) +int __irq_apply_affinity_hint(unsigned int irq, const struct cpumask *m, + bool setaffinity) { unsigned long flags; struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL); @@ -496,12 +497,11 @@ int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m) return -EINVAL; desc->affinity_hint = m; irq_put_desc_unlock(desc, flags); - /* set the initial affinity to prevent every interrupt being on CPU0 */ - if (m) + if (m && setaffinity) __irq_set_affinity(irq, m, false); return 0; } -EXPORT_SYMBOL_GPL(irq_set_affinity_hint); +EXPORT_SYMBOL_GPL(__irq_apply_affinity_hint); static void irq_affinity_notify(struct work_struct *work) {