From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 619452F9DA1 for ; Thu, 26 Mar 2026 21:57:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774562263; cv=none; b=M/hA7C8WgIfiYexqsN530mFW9XJQXuvdIk4PXu1BvLBZCClXfbvLYIvVZsSS8VXh1YRe6rACMoY1zni9YPrieUFRHjtsuv50O8pyOg6ejhQ8qiWqpHnHKm7rOpp0pZo5k6ZL+YyKU2nKk21YNNu6Hf4zp5aEz5GvYLbKO43Fp2w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774562263; c=relaxed/simple; bh=Lp94NCM3MmhGqaDaWHhL1+Hg1pjinsTAZ3yhOCQJqgc=; h=Date:Message-ID:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=UQ6PYpGP3GsaxdbYK/KVO/3YoK5ZdS7FGKABsU5wMvurTsFsweZ6qSbU6HesXJ6LVItqj/K+ra1yig17VC/8gXdJr4vnzEfQfoKeopYj1egw9VEpBLpO5PMa+jUUEp33rKzN0qT+ZzAn6DNwaFhvsvGJTrtvqIrXpdkC65tj2fA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=bSZU9/g9; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="bSZU9/g9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E9D72C2BC87; Thu, 26 Mar 2026 21:57:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1774562263; bh=Lp94NCM3MmhGqaDaWHhL1+Hg1pjinsTAZ3yhOCQJqgc=; h=Date:From:To:Cc:Subject:References:From; b=bSZU9/g9+tzjxov3rFhINtSOYof7tRV8g5HSjr8hMtc8jx6jQArcco02j7+k7fpwE 3k668uqu8buhkWTwpEFc2Wi0DsCiS2C7he8LiX/JMEdyxGq063eFzIyB2ITEQKuOld ANLfT6TsIPS4AFpaJpCnbl/DPu5PCgK2Va5/vJpw1QOdzOucs0t0Lao7CjCwyfUIuB FWPgTb1wwDk4a7M4wJd430eXLBSQgKgbOpLc3uanTIctg/fIXKfDQ9ZyJvO4MIzfN6 2o3UVjOpF8YKpqdukiRRiWDhf2PGX3d4ChXeW0Emwvy1mwk26k9VUSca3GJLgcjBpK ikIarG2fQzLDA== Date: Thu, 26 Mar 2026 22:57:33 +0100 Message-ID: <20260326215036.918489196@kernel.org> User-Agent: quilt/0.68 From: Thomas Gleixner To: LKML Cc: x86@kernel.org, Michael Kelley , Dmitry Ilvokhin , Radu Rendec , Jan Kiszka , Kieran Bingham , Florian Fainelli Subject: [patch V3 10/14] genirq: Calculate precision only when required References: <20260326214345.019130211@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Calculating the precision of the interrupt number column on every initial show_interrupt() invocation is a pointless exercise as the underlying maximum number of interrupts rarely changes. Calculate it only when that number is modified and let show_interrupts() use the cached value. Signed-off-by: Thomas Gleixner Reviewed-by: Dmitry Ilvokhin Reviewed-by: Radu Rendec --- kernel/irq/internals.h | 6 ++++++ kernel/irq/irqdesc.c | 10 ++++++---- kernel/irq/proc.c | 33 +++++++++++++++++++++++---------- 3 files changed, 35 insertions(+), 14 deletions(-) --- a/kernel/irq/internals.h +++ b/kernel/irq/internals.h @@ -134,6 +134,12 @@ static inline void unregister_handler_pr static inline void irq_proc_update_valid(struct irq_desc *desc) { } #endif +#if defined(CONFIG_PROC_FS) && defined(CONFIG_GENERIC_IRQ_SHOW) +void irq_proc_calc_prec(void); +#else +static inline void irq_proc_calc_prec(void) { } +#endif + extern bool irq_can_set_affinity_usr(unsigned int irq); extern int irq_do_set_affinity(struct irq_data *data, --- a/kernel/irq/irqdesc.c +++ b/kernel/irq/irqdesc.c @@ -157,13 +157,12 @@ EXPORT_SYMBOL_GPL(irq_get_nr_irqs); * * Return: @nr. */ -unsigned int irq_set_nr_irqs(unsigned int nr) +unsigned int __init irq_set_nr_irqs(unsigned int nr) { total_nr_irqs = nr; - + irq_proc_calc_prec(); return nr; } -EXPORT_SYMBOL_GPL(irq_set_nr_irqs); static DEFINE_MUTEX(sparse_irq_lock); static struct maple_tree sparse_irqs = MTREE_INIT_EXT(sparse_irqs, @@ -544,6 +543,7 @@ static bool irq_expand_nr_irqs(unsigned if (nr > MAX_SPARSE_IRQS) return false; total_nr_irqs = nr; + irq_proc_calc_prec(); return true; } @@ -572,6 +572,7 @@ int __init early_irq_init(void) desc = alloc_desc(i, node, 0, NULL, NULL); irq_insert_desc(i, desc); } + irq_proc_calc_prec(); return arch_early_irq_init(); } @@ -592,7 +593,7 @@ int __init early_irq_init(void) init_irq_default_affinity(); - printk(KERN_INFO "NR_IRQS: %d\n", NR_IRQS); + pr_info("NR_IRQS: %d\n", NR_IRQS); count = ARRAY_SIZE(irq_desc); @@ -602,6 +603,7 @@ int __init early_irq_init(void) goto __free_desc_res; } + irq_proc_calc_prec(); return arch_early_irq_init(); __free_desc_res: --- a/kernel/irq/proc.c +++ b/kernel/irq/proc.c @@ -456,10 +456,25 @@ int __weak arch_show_interrupts(struct s return 0; } +static struct irq_proc_constraints { + unsigned int num_prec; +} irq_proc_constraints __read_mostly = { + .num_prec = 3, +}; + #ifndef ACTUAL_NR_IRQS # define ACTUAL_NR_IRQS total_nr_irqs #endif +void irq_proc_calc_prec(void) +{ + unsigned int prec, n; + + for (prec = 3, n = 1000; prec < 10 && n <= total_nr_irqs; ++prec) + n *= 10; + WRITE_ONCE(irq_proc_constraints.num_prec, prec); +} + #define ZSTR1 " 0" #define ZSTR1_LEN (sizeof(ZSTR1) - 1) #define ZSTR16 ZSTR1 ZSTR1 ZSTR1 ZSTR1 ZSTR1 ZSTR1 ZSTR1 ZSTR1 \ @@ -498,9 +513,7 @@ void irq_proc_emit_counts(struct seq_fil int show_interrupts(struct seq_file *p, void *v) { - const unsigned int nr_irqs = total_nr_irqs; - static int prec; - + unsigned int prec = READ_ONCE(irq_proc_constraints.num_prec); int i = *(loff_t *) v, j; struct irqaction *action; struct irq_desc *desc; @@ -513,9 +526,6 @@ int show_interrupts(struct seq_file *p, /* print header and calculate the width of the first column */ if (i == 0) { - for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec) - j *= 10; - seq_printf(p, "%*s", prec + 8, ""); for_each_online_cpu(j) seq_printf(p, "CPU%-8d", j); @@ -551,13 +561,16 @@ int show_interrupts(struct seq_file *p, } else { seq_printf(p, "%8s", "None"); } + + seq_putc(p, ' '); if (desc->irq_data.domain) - seq_printf(p, " %*lu", prec, desc->irq_data.hwirq); + seq_put_decimal_ull_width(p, "", desc->irq_data.hwirq, prec); else seq_printf(p, " %*s", prec, ""); -#ifdef CONFIG_GENERIC_IRQ_SHOW_LEVEL - seq_printf(p, " %-8s", irqd_is_level_type(&desc->irq_data) ? "Level" : "Edge"); -#endif + + if (IS_ENABLED(CONFIG_GENERIC_IRQ_SHOW_LEVEL)) + seq_printf(p, " %-8s", irqd_is_level_type(&desc->irq_data) ? "Level" : "Edge"); + if (desc->name) seq_printf(p, "-%-8s", desc->name);