From patchwork Thu Feb 22 09:34:19 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bitao Hu X-Patchwork-Id: 13566944 Received: from out30-130.freemail.mail.aliyun.com (out30-130.freemail.mail.aliyun.com [115.124.30.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2A4843D977; Thu, 22 Feb 2024 09:34:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.130 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708594486; cv=none; b=Y1+9ihh/s7qvqCda7n9jScCoXSeHFR545oZUEsAj9XcC8AUYW24MVeu9NPO7rMaABHwJ9JYxr5xFcu1EGSmIPPUlPRKP+AwyJRgvh+dMhvJJ8czWQV7coZEIqOa+7q+iXQcvfrMu+3EsucMzTbyVcItfmX6ZkcuWPmew2oEpLdg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708594486; c=relaxed/simple; bh=S3pnoOwan+eEQk8IlufjESHCnv633nMQJqvAMBC9eCM=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=IRAN8+N+Lgoz1gbwnQVpWftKHUIoxWWuoNnlukmxkEdOpw2kSiySb7gqaEIYnaySOzuPEsec2UJ05O01tDIq8MghIEEcEnbiuWhDZEfaGZpoSwRkRJ9MePdTn75HC5m1d2LUvnAcATbBQh7YSJEVTI6LikO6po0zDLaHTUjITqE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=Q70XFri/; arc=none smtp.client-ip=115.124.30.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="Q70XFri/" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1708594475; h=From:To:Subject:Date:Message-Id:MIME-Version; bh=UZ9ed8K4qP5FFHD7AieCBC0mwtTJUQra8VKtaAbaIFU=; b=Q70XFri/bhTu5+i1dnNU420gvcBx0d6KwDpL7FH89wa9s2syz7nsCE3wP+c3RZuSoCFzIg1akKZ0ZO/7iBhgt0D0fJGqUo7sqHuf/5HKDAvuRzweZMdivBulMibKikxqZGqAOotjiwzxwBKsZjEzXkqxCpGbT80rUsz5cF1Xb8g= X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R171e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046060;MF=yaoma@linux.alibaba.com;NM=1;PH=DS;RN=16;SR=0;TI=SMTPD_---0W10inyu_1708594471; Received: from localhost.localdomain(mailfrom:yaoma@linux.alibaba.com fp:SMTPD_---0W10inyu_1708594471) by smtp.aliyun-inc.com; Thu, 22 Feb 2024 17:34:33 +0800 From: Bitao Hu To: dianders@chromium.org, akpm@linux-foundation.org, liusong@linux.alibaba.com, tglx@linutronix.de, pmladek@suse.com, kernelfans@gmail.com, deller@gmx.de, npiggin@gmail.com, tsbogend@alpha.franken.de, James.Bottomley@HansenPartnership.com, jan.kiszka@siemens.com Cc: linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, yaoma@linux.alibaba.com Subject: [PATCHv9 2/3] irq: use a struct for the kstat_irqs in the interrupt descriptor Date: Thu, 22 Feb 2024 17:34:19 +0800 Message-Id: <20240222093420.13956-3-yaoma@linux.alibaba.com> X-Mailer: git-send-email 2.37.1 (Apple Git-137.1) In-Reply-To: <20240222093420.13956-1-yaoma@linux.alibaba.com> References: <20240222093420.13956-1-yaoma@linux.alibaba.com> Precedence: bulk X-Mailing-List: linux-mips@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 The current implementation uses an int for the kstat_irqs in the interrupt descriptor. However, we need to know the number of interrupts which happened since softlockup detection took a snapshot in order to analyze the problem caused by an interrupt storm. Replacing an int with a struct and providing sensible interfaces for the watchdog code can keep it self contained to the interrupt core code. Signed-off-by: Bitao Hu --- arch/mips/dec/setup.c | 2 +- arch/parisc/kernel/smp.c | 2 +- arch/powerpc/kvm/book3s_hv_rm_xics.c | 2 +- include/linux/irqdesc.h | 9 ++++++-- include/linux/kernel_stat.h | 3 +++ kernel/irq/internals.h | 2 +- kernel/irq/irqdesc.c | 34 ++++++++++++++++++++++------ kernel/irq/proc.c | 9 +++----- scripts/gdb/linux/interrupts.py | 6 ++--- 9 files changed, 47 insertions(+), 22 deletions(-) diff --git a/arch/mips/dec/setup.c b/arch/mips/dec/setup.c index 6c3704f51d0d..87f0a1436bf9 100644 --- a/arch/mips/dec/setup.c +++ b/arch/mips/dec/setup.c @@ -756,7 +756,7 @@ void __init arch_init_irq(void) NULL)) pr_err("Failed to register fpu interrupt\n"); desc_fpu = irq_to_desc(irq_fpu); - fpu_kstat_irq = this_cpu_ptr(desc_fpu->kstat_irqs); + fpu_kstat_irq = this_cpu_ptr(&desc_fpu->kstat_irqs->cnt); } if (dec_interrupt[DEC_IRQ_CASCADE] >= 0) { if (request_irq(dec_interrupt[DEC_IRQ_CASCADE], no_action, diff --git a/arch/parisc/kernel/smp.c b/arch/parisc/kernel/smp.c index 444154271f23..800eb64e91ad 100644 --- a/arch/parisc/kernel/smp.c +++ b/arch/parisc/kernel/smp.c @@ -344,7 +344,7 @@ static int smp_boot_one_cpu(int cpuid, struct task_struct *idle) struct irq_desc *desc = irq_to_desc(i); if (desc && desc->kstat_irqs) - *per_cpu_ptr(desc->kstat_irqs, cpuid) = 0; + *per_cpu_ptr(desc->kstat_irqs, cpuid) = (struct irqstat) { }; } #endif diff --git a/arch/powerpc/kvm/book3s_hv_rm_xics.c b/arch/powerpc/kvm/book3s_hv_rm_xics.c index e42984878503..f2636414d82a 100644 --- a/arch/powerpc/kvm/book3s_hv_rm_xics.c +++ b/arch/powerpc/kvm/book3s_hv_rm_xics.c @@ -837,7 +837,7 @@ static inline void this_cpu_inc_rm(unsigned int __percpu *addr) */ static void kvmppc_rm_handle_irq_desc(struct irq_desc *desc) { - this_cpu_inc_rm(desc->kstat_irqs); + this_cpu_inc_rm(&desc->kstat_irqs->cnt); __this_cpu_inc(kstat.irqs_sum); } diff --git a/include/linux/irqdesc.h b/include/linux/irqdesc.h index d9451d456a73..2912b1998670 100644 --- a/include/linux/irqdesc.h +++ b/include/linux/irqdesc.h @@ -17,6 +17,11 @@ struct irq_desc; struct irq_domain; struct pt_regs; +struct irqstat { + unsigned int cnt; + unsigned int ref; +}; + /** * struct irq_desc - interrupt descriptor * @irq_common_data: per irq and chip data passed down to chip functions @@ -55,7 +60,7 @@ struct pt_regs; struct irq_desc { struct irq_common_data irq_common_data; struct irq_data irq_data; - unsigned int __percpu *kstat_irqs; + struct irqstat __percpu *kstat_irqs; irq_flow_handler_t handle_irq; struct irqaction *action; /* IRQ action list */ unsigned int status_use_accessors; @@ -119,7 +124,7 @@ extern struct irq_desc irq_desc[NR_IRQS]; static inline unsigned int irq_desc_kstat_cpu(struct irq_desc *desc, unsigned int cpu) { - return desc->kstat_irqs ? *per_cpu_ptr(desc->kstat_irqs, cpu) : 0; + return desc->kstat_irqs ? per_cpu(desc->kstat_irqs->cnt, cpu) : 0; } static inline struct irq_desc *irq_data_to_desc(struct irq_data *data) diff --git a/include/linux/kernel_stat.h b/include/linux/kernel_stat.h index 9935f7ecbfb9..98b3043ea5e6 100644 --- a/include/linux/kernel_stat.h +++ b/include/linux/kernel_stat.h @@ -79,6 +79,9 @@ static inline unsigned int kstat_cpu_softirqs_sum(int cpu) return sum; } +extern void kstat_snapshot_irqs(void); +extern unsigned int kstat_get_irq_since_snapshot(unsigned int irq); + /* * Number of interrupts per specific IRQ source, since bootup */ diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h index bcc7f21db9ee..1d92532c2aae 100644 --- a/kernel/irq/internals.h +++ b/kernel/irq/internals.h @@ -258,7 +258,7 @@ static inline void irq_state_set_masked(struct irq_desc *desc) static inline void __kstat_incr_irqs_this_cpu(struct irq_desc *desc) { - __this_cpu_inc(*desc->kstat_irqs); + __this_cpu_inc(desc->kstat_irqs->cnt); __this_cpu_inc(kstat.irqs_sum); } diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c index 27ca1c866f29..9cd17080b2d8 100644 --- a/kernel/irq/irqdesc.c +++ b/kernel/irq/irqdesc.c @@ -122,7 +122,7 @@ static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node, desc->name = NULL; desc->owner = owner; for_each_possible_cpu(cpu) - *per_cpu_ptr(desc->kstat_irqs, cpu) = 0; + *per_cpu_ptr(desc->kstat_irqs, cpu) = (struct irqstat) { }; desc_smp_init(desc, node, affinity); } @@ -418,8 +418,8 @@ static struct irq_desc *alloc_desc(int irq, int node, unsigned int flags, desc = kzalloc_node(sizeof(*desc), GFP_KERNEL, node); if (!desc) return NULL; - /* allocate based on nr_cpu_ids */ - desc->kstat_irqs = alloc_percpu(unsigned int); + + desc->kstat_irqs = alloc_percpu(struct irqstat); if (!desc->kstat_irqs) goto err_desc; @@ -593,7 +593,7 @@ int __init early_irq_init(void) count = ARRAY_SIZE(irq_desc); for (i = 0; i < count; i++) { - desc[i].kstat_irqs = alloc_percpu(unsigned int); + desc[i].kstat_irqs = alloc_percpu(struct irqstat); alloc_masks(&desc[i], node); raw_spin_lock_init(&desc[i].lock); lockdep_set_class(&desc[i].lock, &irq_desc_lock_class); @@ -952,8 +952,7 @@ unsigned int kstat_irqs_cpu(unsigned int irq, int cpu) { struct irq_desc *desc = irq_to_desc(irq); - return desc && desc->kstat_irqs ? - *per_cpu_ptr(desc->kstat_irqs, cpu) : 0; + return desc && desc->kstat_irqs ? per_cpu(desc->kstat_irqs->cnt, cpu) : 0; } static bool irq_is_nmi(struct irq_desc *desc) @@ -975,10 +974,31 @@ static unsigned int kstat_irqs(unsigned int irq) return data_race(desc->tot_count); for_each_possible_cpu(cpu) - sum += data_race(*per_cpu_ptr(desc->kstat_irqs, cpu)); + sum += data_race(per_cpu(desc->kstat_irqs->cnt, cpu)); return sum; } +void kstat_snapshot_irqs(void) +{ + struct irq_desc *desc; + unsigned int irq; + + for_each_irq_desc(irq, desc) { + if (!desc->kstat_irqs) + continue; + this_cpu_write(desc->kstat_irqs->ref, this_cpu_read(desc->kstat_irqs->cnt)); + } +} + +unsigned int kstat_get_irq_since_snapshot(unsigned int irq) +{ + struct irq_desc *desc = irq_to_desc(irq); + + if (!desc || !desc->kstat_irqs) + return 0; + return this_cpu_read(desc->kstat_irqs->cnt) - this_cpu_read(desc->kstat_irqs->ref); +} + /** * kstat_irqs_usr - Get the statistics for an interrupt from thread context * @irq: The interrupt number diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c index 623b8136e9af..3ad40cf30c66 100644 --- a/kernel/irq/proc.c +++ b/kernel/irq/proc.c @@ -488,18 +488,15 @@ int show_interrupts(struct seq_file *p, void *v) if (!desc || irq_settings_is_hidden(desc)) goto outsparse; - if (desc->kstat_irqs) { - for_each_online_cpu(j) - any_count |= data_race(*per_cpu_ptr(desc->kstat_irqs, j)); - } + if (desc->kstat_irqs) + any_count = data_race(desc->tot_count); if ((!desc->action || irq_desc_is_chained(desc)) && !any_count) goto outsparse; seq_printf(p, "%*d: ", prec, i); for_each_online_cpu(j) - seq_printf(p, "%10u ", desc->kstat_irqs ? - *per_cpu_ptr(desc->kstat_irqs, j) : 0); + seq_printf(p, "%10u ", desc->kstat_irqs ? per_cpu(desc->kstat_irqs->cnt, j) : 0); raw_spin_lock_irqsave(&desc->lock, flags); if (desc->irq_data.chip) { diff --git a/scripts/gdb/linux/interrupts.py b/scripts/gdb/linux/interrupts.py index ef478e273791..7e50f3b9dfad 100644 --- a/scripts/gdb/linux/interrupts.py +++ b/scripts/gdb/linux/interrupts.py @@ -37,7 +37,7 @@ def show_irq_desc(prec, irq): any_count = 0 if desc['kstat_irqs']: for cpu in cpus.each_online_cpu(): - any_count += cpus.per_cpu(desc['kstat_irqs'], cpu) + any_count += cpus.per_cpu(desc['kstat_irqs'], cpu)['cnt'] if (desc['action'] == 0 or irq_desc_is_chained(desc)) and any_count == 0: return text; @@ -45,7 +45,7 @@ def show_irq_desc(prec, irq): text += "%*d: " % (prec, irq) for cpu in cpus.each_online_cpu(): if desc['kstat_irqs']: - count = cpus.per_cpu(desc['kstat_irqs'], cpu) + count = cpus.per_cpu(desc['kstat_irqs'], cpu)['cnt'] else: count = 0 text += "%10u" % (count) @@ -177,7 +177,7 @@ def arm_common_show_interrupts(prec): if desc == 0: continue for cpu in cpus.each_online_cpu(): - text += "%10u" % (cpus.per_cpu(desc['kstat_irqs'], cpu)) + text += "%10u" % (cpus.per_cpu(desc['kstat_irqs'], cpu)['cnt']) text += " %s" % (ipi_types[ipi].string()) text += "\n" return text