From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754336Ab0CVOEm (ORCPT ); Mon, 22 Mar 2010 10:04:42 -0400 Received: from out01.mta.xmission.com ([166.70.13.231]:36700 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752014Ab0CVOEl (ORCPT ); Mon, 22 Mar 2010 10:04:41 -0400 To: Thomas Gleixner Cc: Yinghai Lu , Ingo Molnar , "H. Peter Anvin" , Andrew Morton , Jesse Barnes , linux-kernel@vger.kernel.org Subject: Re: [PATCH 05/10] x86: use vector_desc instead of vector_irq References: <1269221770-9667-1-git-send-email-yinghai@kernel.org> <1269221770-9667-6-git-send-email-yinghai@kernel.org> From: ebiederm@xmission.com (Eric W. Biederman) Date: Mon, 22 Mar 2010 07:04:35 -0700 In-Reply-To: (Thomas Gleixner's message of "Mon\, 22 Mar 2010 14\:58\:29 +0100 \(CET\)") Message-ID: User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-XM-SPF: eid=;;;mid=;;;hst=in01.mta.xmission.com;;;ip=76.21.114.89;;;frm=ebiederm@xmission.com;;;spf=neutral X-SA-Exim-Connect-IP: 76.21.114.89 X-SA-Exim-Rcpt-To: tglx@linutronix.de, linux-kernel@vger.kernel.org, jbarnes@virtuousgeek.org, akpm@linux-foundation.org, hpa@zytor.com, mingo@elte.hu, yinghai@kernel.org X-SA-Exim-Mail-From: ebiederm@xmission.com X-SA-Exim-Scanned: No (on in01.mta.xmission.com); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Thomas Gleixner writes: > On Sun, 21 Mar 2010, Yinghai Lu wrote: > >> Eric pointed out that radix tree version of irq_to_desc will magnify delay on >> the path of handle_irq. >> >> use vector_desc to reduce the calling of irq_to_desc. >> >> next step: need to change all ack, mask, umask, eoi for all irq_chip to take irq_desc > > That's not relevant for this change. > >> >> -typedef int vector_irq_t[NR_VECTORS]; >> -DECLARE_PER_CPU(vector_irq_t, vector_irq); >> -extern void setup_vector_irq(int cpu); >> +typedef struct irq_desc *vector_desc_t[NR_VECTORS]; > > Why do we need that typedef ? Please use plain struct irq_desc * Well at least originally DECLARE_PER_CPU chocked when given a complex type. Does: DECLARE_PER_CPU(struct irq_desc *[NR_VECTORS], vector_desc); work? >> +DECLARE_PER_CPU(vector_desc_t, vector_desc); >> +extern void setup_vector_desc(int cpu); > ... >> void destroy_irq(unsigned int irq) >> { >> unsigned long flags; >> + struct irq_desc *desc; >> + struct irq_cfg *cfg; >> >> dynamic_irq_cleanup_keep_chip_data(irq); >> >> free_irte(irq); >> raw_spin_lock_irqsave(&vector_lock, flags); >> - __clear_irq_vector(irq, get_irq_chip_data(irq)); >> + desc = irq_to_desc(irq); >> + cfg = desc->chip_data; >> + __clear_irq_vector(desc, cfg); > > __clear_irq_vector(desc, desc->chip_data); > > should be sufficient, right ? You want to deliberately loose a modicum of type safety? > >> raw_spin_unlock_irqrestore(&vector_lock, flags); >> } >> >> @@ -3377,6 +3376,7 @@ void destroy_irq(unsigned int irq) >> static int msi_compose_msg(struct pci_dev *pdev, unsigned int irq, >> struct msi_msg *msg, u8 hpet_id) >> { >> + struct irq_desc *desc; >> struct irq_cfg *cfg; >> int err; >> unsigned dest; >> @@ -3384,8 +3384,9 @@ static int msi_compose_msg(struct pci_dev *pdev, unsigned int irq, >> if (disable_apic) >> return -ENXIO; >> >> - cfg = irq_cfg(irq); >> - err = assign_irq_vector(irq, cfg, apic->target_cpus()); >> + desc = irq_to_desc(irq); >> + cfg = desc->chip_data; >> + err = assign_irq_vector(desc, cfg, apic->target_cpus()); > > Ditto > >> if (err) >> return err; >> >> @@ -3876,14 +3877,16 @@ static struct irq_chip ht_irq_chip = { >> >> int arch_setup_ht_irq(unsigned int irq, struct pci_dev *dev) >> { >> + struct irq_desc *desc; >> struct irq_cfg *cfg; >> int err; >> >> if (disable_apic) >> return -ENXIO; >> >> - cfg = irq_cfg(irq); >> - err = assign_irq_vector(irq, cfg, apic->target_cpus()); >> + desc = irq_to_desc(irq); >> + cfg = desc->chip_data; >> + err = assign_irq_vector(desc, cfg, apic->target_cpus()); > > Ditto > >> if (!err) { >> struct ht_irq_msg msg; >> unsigned dest; >> diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c >> index 91fd0c7..f71625c 100644 >> --- a/arch/x86/kernel/irq.c >> +++ b/arch/x86/kernel/irq.c >> @@ -229,19 +229,19 @@ unsigned int __irq_entry do_IRQ(struct pt_regs *regs) >> >> /* high bit used in ret_from_ code */ >> unsigned vector = ~regs->orig_ax; >> - unsigned irq; >> + struct irq_desc *desc; >> >> exit_idle(); >> irq_enter(); >> >> - irq = __get_cpu_var(vector_irq)[vector]; >> + desc = __get_cpu_var(vector_desc)[vector]; >> >> - if (!handle_irq(irq, regs)) { >> + if (!handle_irq(desc, regs)) { >> ack_APIC_irq(); >> >> if (printk_ratelimit()) >> - pr_emerg("%s: %d.%d No irq handler for vector (irq %d)\n", >> - __func__, smp_processor_id(), vector, irq); >> + pr_emerg("%s: %d.%d No irq handler for vector\n", > > That printk is confusing. It's not lacking an irq handler. The > vector is simply not assigned. Long evolution. Do you have a suggestion of better wording? Eric