From patchwork Tue Jan 20 05:51:53 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiang Liu X-Patchwork-Id: 430876 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 54B8E1400A0 for ; Tue, 20 Jan 2015 16:57:38 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753667AbbATF5Q (ORCPT ); Tue, 20 Jan 2015 00:57:16 -0500 Received: from mga11.intel.com ([192.55.52.93]:23692 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753665AbbATF5N (ORCPT ); Tue, 20 Jan 2015 00:57:13 -0500 Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga102.fm.intel.com with ESMTP; 19 Jan 2015 21:57:13 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.09,432,1418112000"; d="scan'208";a="664448758" Received: from gerry-dev.bj.intel.com ([10.238.158.52]) by fmsmga002.fm.intel.com with ESMTP; 19 Jan 2015 21:57:00 -0800 From: Jiang Liu To: Bjorn Helgaas , Benjamin Herrenschmidt , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , "Rafael J. Wysocki" , Randy Dunlap , Yinghai Lu , Borislav Petkov , Dimitri Sivanich , x86@kernel.org, Jiang Liu Cc: Konrad Rzeszutek Wilk , David Cohen , Sander Eikelenboom , David Vrabel , Andrew Morton , Tony Luck , Joerg Roedel , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-acpi@vger.kernel.org Subject: [Patch Part2 v4 33/33] x86/irq: Avoid memory allocation in __assign_irq_vector() Date: Tue, 20 Jan 2015 13:51:53 +0800 Message-Id: <1421733113-15704-34-git-send-email-jiang.liu@linux.intel.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1421733113-15704-1-git-send-email-jiang.liu@linux.intel.com> References: <1421733113-15704-1-git-send-email-jiang.liu@linux.intel.com> Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Function __assign_irq_vector() is protected by vector_lock, so use a global temporary cpu_mask to avoid allocating/freeing cpu_mask. Signed-off-by: Jiang Liu --- arch/x86/kernel/apic/vector.c | 33 +++++++++++++++++---------------- 1 file changed, 17 insertions(+), 16 deletions(-) diff --git a/arch/x86/kernel/apic/vector.c b/arch/x86/kernel/apic/vector.c index f5eb3999383f..4a04b25cdcdf 100644 --- a/arch/x86/kernel/apic/vector.c +++ b/arch/x86/kernel/apic/vector.c @@ -30,6 +30,7 @@ struct apic_chip_data { struct irq_domain *x86_vector_domain; static DEFINE_RAW_SPINLOCK(vector_lock); +static cpumask_var_t vector_cpumask; static struct irq_chip lapic_controller; #ifdef CONFIG_X86_IO_APIC static struct apic_chip_data *legacy_irq_data[NR_IRQS_LEGACY]; @@ -116,14 +117,10 @@ static int __assign_irq_vector(int irq, struct apic_chip_data *d, static int current_vector = FIRST_EXTERNAL_VECTOR + VECTOR_OFFSET_START; static int current_offset = VECTOR_OFFSET_START % 16; int cpu, err; - cpumask_var_t tmp_mask; if (d->move_in_progress) return -EBUSY; - if (!alloc_cpumask_var(&tmp_mask, GFP_ATOMIC)) - return -ENOMEM; - /* Only try and allocate irqs on cpus that are present */ err = -ENOSPC; cpumask_clear(d->old_domain); @@ -131,21 +128,22 @@ static int __assign_irq_vector(int irq, struct apic_chip_data *d, while (cpu < nr_cpu_ids) { int new_cpu, vector, offset; - apic->vector_allocation_domain(cpu, tmp_mask, mask); + apic->vector_allocation_domain(cpu, vector_cpumask, mask); - if (cpumask_subset(tmp_mask, d->domain)) { + if (cpumask_subset(vector_cpumask, d->domain)) { err = 0; - if (cpumask_equal(tmp_mask, d->domain)) + if (cpumask_equal(vector_cpumask, d->domain)) break; /* * New cpumask using the vector is a proper subset of * the current in use mask. So cleanup the vector * allocation for the members that are not used anymore. */ - cpumask_andnot(d->old_domain, d->domain, tmp_mask); + cpumask_andnot(d->old_domain, d->domain, + vector_cpumask); d->move_in_progress = cpumask_intersects(d->old_domain, cpu_online_mask); - cpumask_and(d->domain, d->domain, tmp_mask); + cpumask_and(d->domain, d->domain, vector_cpumask); break; } @@ -159,16 +157,18 @@ next: } if (unlikely(current_vector == vector)) { - cpumask_or(d->old_domain, d->old_domain, tmp_mask); - cpumask_andnot(tmp_mask, mask, d->old_domain); - cpu = cpumask_first_and(tmp_mask, cpu_online_mask); + cpumask_or(d->old_domain, d->old_domain, + vector_cpumask); + cpumask_andnot(vector_cpumask, mask, d->old_domain); + cpu = cpumask_first_and(vector_cpumask, + cpu_online_mask); continue; } if (test_bit(vector, used_vectors)) goto next; - for_each_cpu_and(new_cpu, tmp_mask, cpu_online_mask) { + for_each_cpu_and(new_cpu, vector_cpumask, cpu_online_mask) { if (per_cpu(vector_irq, new_cpu)[vector] > VECTOR_UNDEFINED) goto next; @@ -181,14 +181,13 @@ next: d->move_in_progress = cpumask_intersects(d->old_domain, cpu_online_mask); } - for_each_cpu_and(new_cpu, tmp_mask, cpu_online_mask) + for_each_cpu_and(new_cpu, vector_cpumask, cpu_online_mask) per_cpu(vector_irq, new_cpu)[vector] = irq; d->cfg.vector = vector; - cpumask_copy(d->domain, tmp_mask); + cpumask_copy(d->domain, vector_cpumask); err = 0; break; } - free_cpumask_var(tmp_mask); if (!err) { /* cache destination APIC IDs into cfg->dest_apicid */ @@ -397,6 +396,8 @@ int __init arch_early_irq_init(void) arch_init_msi_domain(x86_vector_domain); arch_init_htirq_domain(x86_vector_domain); + BUG_ON(!alloc_cpumask_var(&vector_cpumask, GFP_KERNEL)); + return arch_early_ioapic_init(); }