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 07BF62FF669 for ; Fri, 20 Mar 2026 13:22:02 +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=1774012923; cv=none; b=oBM54wCpglSoRvehdwuSD6rvpxM3gNoYtwJD9MaSCboLV2D6xvx4b3Bft22pq87Di0twDh5aomwh/EHiBlY2KvKnkzLxM5q/vBjeP7PdzPKf8rS6EMNOd8kA4v1KuiEEUpi4IVWlL1mmFlbv3kF1PUakGZ+cNEYueC1dSn79JfE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774012923; c=relaxed/simple; bh=Pw0OxlaQJR8gAbEtrzFM7V2QRmxkbMl1QxymPeUXn10=; h=Date:Message-ID:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=Hc05Yyj6jTpscM4DEzc6//SzfehyJ3nHrTszdmcJgo0ByJvc0yy08rXZz2mzp+CxCZdLTg2pXXVrKBX8+Gy112fJpoYHqmYJZbb2LCNYJdruFhXTsV5+q8EwiCqzcGiIUMan6qd1aGxo6ojS02w6Wg9wMhzMaio80VQGIwmf9sM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=M1Bt8Oqq; 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="M1Bt8Oqq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1E870C4CEF7; Fri, 20 Mar 2026 13:22:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1774012922; bh=Pw0OxlaQJR8gAbEtrzFM7V2QRmxkbMl1QxymPeUXn10=; h=Date:From:To:Cc:Subject:References:From; b=M1Bt8Oqq4PPdyB3rqjPo+YFD0gH0raoY40gPFhjEv+d3jGl67WK8MSUETvF+Y6sit 2IfccRNLiZUU9p1MupukXvk+NTR5T+W6TiP+fGfJaBZoSlMgEtkxytMUh/7qz06wB2 aIaE7oAUNBvU1wCA16X1xkN5Rm8e9NXuNmq3raNEtYQDMs9ZcYJFMQKG5pimqp43JR 9wxvR7HYZYPlT9MRS50xnCEfvp85rq5YyPw188T41tEHK7CSVnuGL8NN0psDmZ84dX nA3GqEEafJdYaK4GTXIPOXlPIy49EKRpGLc1IpkvLzfn25HnopgvH/dAN9GjZQ6zco 3+XxmLyLyYr+Q== Date: Fri, 20 Mar 2026 14:21:59 +0100 Message-ID: <20260320132102.498431075@kernel.org> User-Agent: quilt/0.68 From: Thomas Gleixner To: LKML Cc: x86@kernel.org, Dmitry Ilvokhin , Neil Horman , Radu Rendec Subject: [patch v2 07/14] genirq: Calculate precision only when required References: <20260320131108.344376329@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 --- kernel/irq/internals.h | 6 ++++++ kernel/irq/irqdesc.c | 10 ++++++---- kernel/irq/proc.c | 28 +++++++++++++++++++--------- 3 files changed, 31 insertions(+), 13 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 @@ -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 (sizeof(ZSTR1) - 1) #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);