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 DE4C73DA5A6 for ; Wed, 4 Mar 2026 18:56:01 +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=1772650562; cv=none; b=MJgABAs/yELuOwfiuCfktHgMg2fPFpxvWFXxJGJWiOg5LiTkd+ITDX20Ai0XrzEzno3b2kgNVZihEXQZhNzlt8yOK36n8qz631cQsxM4BwOb0g/eGUjmIyi13eTx+2WvgPg8XjFH8l5oW9dKZZfj9OTZupb6RBt+0gGr/ju+b+Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772650562; c=relaxed/simple; bh=O6MV+XeAU0ooSXDYEg1TFDDp7I4Fk1tqjohxewwRhpc=; h=Date:Message-ID:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=nr5dNuL6ivXwgXsqXdQ9uQX6vm1dE5NwQ+/tRKLFJa60vHzjbNlw1l5ATaqT3JHIAf4R/ZaYrzuyEzu8M6PvCH2Io7rlQ9oC0FpZQ4DgLFFYTlXvtGZhslBlniEZVL4uDnEeUKm/JzH95Tqlu7CeYjRG4V7wcV3d5mIOS8TYjYA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=XzmifzCy; 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="XzmifzCy" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E5395C2BC86; Wed, 4 Mar 2026 18:56:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772650561; bh=O6MV+XeAU0ooSXDYEg1TFDDp7I4Fk1tqjohxewwRhpc=; h=Date:From:To:Cc:Subject:References:From; b=XzmifzCyqaUFONL690OycRs6smkEiXeTNJwxZNsgfMfWuA3fE23o/Cs+dMH9LEGlU 5xLWqFLXLT80ZoTJm9z0tkteB4X8g/Pyp0MntCqghGrAlyZOHUWoa52JzZ1WJ2oW8m qCrVRfk6MQdDpNVEjLZnF2NrrUx1gzBrxAdMm8KQH9+cvQjTQmKVZpnCnmxKnZslvD jfBhBufOaiqSKlV4e7gETenEkXnyi7Q5HNP1GHTf2lmuQL659deMeCmEKQyLyHWInC x+Sg9dcrOF3yf38c8aCF6ofveMEYGoOgGFgsRT6X/8KgGq01OZZzOHYdFb1adCkxQF EaEH+EFcs6swA== Date: Wed, 04 Mar 2026 19:55:58 +0100 Message-ID: <20260303154548.435226377@kernel.org> User-Agent: quilt/0.68 From: Thomas Gleixner To: LKML Cc: x86@kernel.org, Dmitry Ilvokhin , Neil Horman Subject: [patch 07/14] genirq: Calculate precision only when required References: <20260303150539.513068586@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 --- kernel/irq/internals.h | 2 ++ kernel/irq/irqdesc.c | 10 ++++++---- kernel/irq/proc.c | 28 +++++++++++++++++++--------- 3 files changed, 27 insertions(+), 13 deletions(-) --- a/kernel/irq/internals.h +++ b/kernel/irq/internals.h @@ -124,6 +124,7 @@ extern void unregister_irq_proc(unsigned extern void register_handler_proc(unsigned int irq, struct irqaction *action); extern void unregister_handler_proc(unsigned int irq, struct irqaction *action); void irq_proc_update_valid(struct irq_desc *desc); +void irq_proc_calc_prec(void); #else static inline void register_irq_proc(unsigned int irq, struct irq_desc *desc) { } static inline void unregister_irq_proc(unsigned int irq, struct irq_desc *desc) { } @@ -132,6 +133,7 @@ static inline void register_handler_proc static inline void unregister_handler_proc(unsigned int irq, struct irqaction *action) { } static inline void irq_proc_update_valid(struct irq_desc *desc) { } +static inline void irq_proc_calc_prec(void) { } #endif extern bool irq_can_set_affinity_usr(unsigned int irq); --- 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 @@ -457,10 +457,21 @@ int __weak arch_show_interrupts(struct s return 0; } +static int irq_num_prec __read_mostly = 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_num_prec, prec); +} + #define ZSTR1 " 0" #define ZSTR1_LEN 11 #define ZSTR16 ZSTR1 ZSTR1 ZSTR1 ZSTR1 ZSTR1 ZSTR1 ZSTR1 ZSTR1 \ @@ -499,8 +510,7 @@ void irq_proc_emit_counts(struct seq_fil int show_interrupts(struct seq_file *p, void *v) { - const unsigned int nr_irqs = irq_get_nr_irqs(); - static int prec; + int prec = READ_ONCE(irq_num_prec); int i = *(loff_t *) v, j; struct irqaction *action; @@ -514,9 +524,6 @@ 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); @@ -552,13 +559,16 @@ 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);