From patchwork Tue Oct 22 11:29:32 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Philip Cox X-Patchwork-Id: 2000449 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.ubuntu.com (client-ip=185.125.189.65; helo=lists.ubuntu.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=patchwork.ozlabs.org) Received: from lists.ubuntu.com (lists.ubuntu.com [185.125.189.65]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4XXqjP17cmz1xvv for ; Tue, 22 Oct 2024 22:30:17 +1100 (AEDT) Received: from localhost ([127.0.0.1] helo=lists.ubuntu.com) by lists.ubuntu.com with esmtp (Exim 4.86_2) (envelope-from ) id 1t3D5S-0006WZ-WF; Tue, 22 Oct 2024 11:30:07 +0000 Received: from smtp-relay-internal-1.internal ([10.131.114.114] helo=smtp-relay-internal-1.canonical.com) by lists.ubuntu.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1t3D5P-0006U7-Gd for kernel-team@lists.ubuntu.com; Tue, 22 Oct 2024 11:30:03 +0000 Received: from mail-vk1-f198.google.com (mail-vk1-f198.google.com [209.85.221.198]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by smtp-relay-internal-1.canonical.com (Postfix) with ESMTPS id 4A6433F28C for ; Tue, 22 Oct 2024 11:30:03 +0000 (UTC) Received: by mail-vk1-f198.google.com with SMTP id 71dfb90a1353d-50d83a838b3so1646876e0c.0 for ; Tue, 22 Oct 2024 04:30:03 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1729596599; x=1730201399; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=b+c2uVlTG01oShnm/+RbHlUMwXURPUbLY3wETJ+mZYg=; b=hRJGBXWpoS67od1Og5Rm9UdUFyMTxU5W14++SwYn1FBrNZ1qWdLk7XLvNoWwp+PqAF zqNUatLRq1UkJre9mzAwLPS+ajoA5EiKJ06tkwNDrf7xVZwrIgyVm69GAuv0QMBmEWRi MlfaX/+67HfRbwQ6quKBMBVTilS4WBRCSWW5G06hm4ILCWY3KoViUP8jtn6Qk9SR7ufC yhxzsP6vu2J+qABBPDR52+4Ju6ki3z1FLHnE5JB982AQFhOiuJv/euBGbtZ8J/Jmog+X u6uGry7owWXYhbu6qF4OXGi+Um/hMgkNzx4GFXUHLr8ay+aAQMLYE8uVbCMfcwBzBZOz ohIg== X-Gm-Message-State: AOJu0Yw74pzUuhrICvz9QcbFF6fioz6RpKOHfWLuS/CQs2zf2Sa00ff8 ou9oxwOpe6qS557F/YBo6HCxkwVZtelLpUtBqO50qgwHsBVm8iXyfj/L6urDa5ZiUMTW1UUFIeu iWpk91/YbpDzCjCNWnhD050GLDvlezZRlP71DlEtE4iYrvycpfNEs0DkOf62M2JuGFTcHO8Kxav 9jEh1NVgJsrg== X-Received: by 2002:a05:6122:2a09:b0:50a:49d1:f1f with SMTP id 71dfb90a1353d-50fb62cf120mr2116872e0c.13.1729596598954; Tue, 22 Oct 2024 04:29:58 -0700 (PDT) X-Google-Smtp-Source: AGHT+IEXR9M5c/AJaWkdScF8Cb1JMA8do+wbo3f7oxqpj7yXrlO6ELmi/X89e0LRlNBpEQ5PGZhuXA== X-Received: by 2002:a05:6122:2a09:b0:50a:49d1:f1f with SMTP id 71dfb90a1353d-50fb62cf120mr2116839e0c.13.1729596598528; Tue, 22 Oct 2024 04:29:58 -0700 (PDT) Received: from cox.home.arpa ([174.88.10.82]) by smtp.gmail.com with ESMTPSA id af79cd13be357-7b165a883f1sm268426685a.130.2024.10.22.04.29.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 22 Oct 2024 04:29:57 -0700 (PDT) From: Philip Cox To: kernel-team@lists.ubuntu.com Subject: [SRU][AWS][J][[PATCH 1/2] genirq: Provide new interfaces for affinity hints Date: Tue, 22 Oct 2024 07:29:32 -0400 Message-Id: <20241022112935.23113-4-philip.cox@canonical.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20241022112935.23113-1-philip.cox@canonical.com> References: <20241022112935.23113-1-philip.cox@canonical.com> MIME-Version: 1.0 X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" From: Thomas Gleixner BugLink: https://bugs.launchpad.net/bugs/2085159 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. 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 Signed-off-by: Thomas Gleixner Reviewed-by: Ming Lei Link: https://lore.kernel.org/r/20210501021832.743094-1-jesse.brandeburg@intel.com Link: https://lore.kernel.org/r/20210903152430.244937-2-nitesh@redhat.com (cherry picked from commit 65c7cdedeb3026fabcc967a7aae2f755ad4d0783) Signed-off-by: Philip Cox --- 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 1f22a30c0963..9367f1cb2e3c 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -329,7 +329,46 @@ 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 + * @m: 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 + * @m: cpumask pointer (NULL to clear the hint) + * + * Updates the affinity hint and if @m 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); @@ -361,6 +400,18 @@ 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 b46fbfbb929f..ce0433446a8e 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -501,7 +501,8 @@ 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); @@ -510,12 +511,11 @@ 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) {