From: Thomas Gleixner <tglx@kernel.org>
Date: Sun, 17 May 2026 20:02:29 +0000 (+0200)
Subject: genirq/proc: Increase default interrupt number precision to four
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=34594da7650d3ea67f96c0f4034ff6b2453f67c3;p=thirdparty%2Flinux.git

genirq/proc: Increase default interrupt number precision to four

Quite some architectures have four character wide acronyms for architecture
specific interrupts like IPI, NMI, etc.

The default precision of printing the Linux device interrupt numbers is
three, which causes quite some code to play games with adding or omitting
space after the acronym and the colon in order to keep the per CPU numbers
properly aligned.

Increase the default number precision to four in the core code and get rid
of the space games all over the place. At the same time align all
architecture specific descriptor texts left so that they show up in the
same column as the interrupt chip names, which makes the output more
uniform accross architectures. Fix up the GDB script to this new scheme as
well.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20260517194931.839482411@kernel.org
---

diff --git a/arch/alpha/kernel/irq.c b/arch/alpha/kernel/irq.c
index c67047c5d8304..4a6a8b1d5a8b1 100644
--- a/arch/alpha/kernel/irq.c
+++ b/arch/alpha/kernel/irq.c
@@ -72,16 +72,16 @@ int arch_show_interrupts(struct seq_file *p, int prec)
 	int j;
 
 #ifdef CONFIG_SMP
-	seq_puts(p, "IPI: ");
+	seq_puts(p, " IPI: ");
 	for_each_online_cpu(j)
 		seq_printf(p, "%10lu ", cpu_data[j].ipi_count);
 	seq_putc(p, '\n');
 #endif
-	seq_puts(p, "PMI: ");
+	seq_puts(p, " PMI: ");
 	for_each_online_cpu(j)
 		seq_printf(p, "%10lu ", per_cpu(irq_pmi_count, j));
-	seq_puts(p, "          Performance Monitoring\n");
-	seq_printf(p, "ERR: %10lu\n", irq_err_count);
+	seq_puts(p, " Performance Monitoring\n");
+	seq_printf(p, " ERR: %10lu\n", irq_err_count);
 	return 0;
 }
 
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index 4e8e89a26ca32..b5fb4697bc3f8 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -551,8 +551,7 @@ void show_ipi_list(struct seq_file *p, int prec)
 		if (!ipi_desc[i])
 			continue;
 
-		seq_printf(p, "%*s%u:%s", prec - 1, "IPI", i,
-			   prec >= 4 ? " " : "");
+		seq_printf(p, "%*s%u:", prec - 1, "IPI", i);
 
 		for_each_online_cpu(cpu)
 			seq_printf(p, "%10u ", irq_desc_kstat_cpu(ipi_desc[i], cpu));
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index 1aa324104afb4..1d0e0e6a5b926 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -833,11 +833,10 @@ int arch_show_interrupts(struct seq_file *p, int prec)
 	unsigned int cpu, i;
 
 	for (i = 0; i < MAX_IPI; i++) {
-		seq_printf(p, "%*s%u:%s", prec - 1, "IPI", i,
-			   prec >= 4 ? " " : "");
+		seq_printf(p, "%*s%u: ", prec - 1, "IPI", i);
 		for_each_online_cpu(cpu)
 			seq_printf(p, "%10u ", irq_desc_kstat_cpu(get_ipi_desc(cpu, i), cpu));
-		seq_printf(p, "      %s\n", ipi_types[i]);
+		seq_printf(p, " %s\n", ipi_types[i]);
 	}
 
 	seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count);
diff --git a/arch/loongarch/kernel/smp.c b/arch/loongarch/kernel/smp.c
index 64a048f1b8803..50922610758ba 100644
--- a/arch/loongarch/kernel/smp.c
+++ b/arch/loongarch/kernel/smp.c
@@ -88,7 +88,7 @@ void show_ipi_list(struct seq_file *p, int prec)
 	unsigned int cpu, i;
 
 	for (i = 0; i < NR_IPI; i++) {
-		seq_printf(p, "%*s%u:%s", prec - 1, "IPI", i, prec >= 4 ? " " : "");
+		seq_printf(p, "%*s%u:", prec - 1, "IPI", i);
 		for_each_online_cpu(cpu)
 			seq_put_decimal_ull_width(p, " ", per_cpu(irq_stat, cpu).ipi_irqs[i], 10);
 		seq_printf(p, " LoongArch  %d  %s\n", i + 1, ipi_types[i]);
diff --git a/arch/riscv/kernel/smp.c b/arch/riscv/kernel/smp.c
index 5ed5095320e66..fa66f9c97d748 100644
--- a/arch/riscv/kernel/smp.c
+++ b/arch/riscv/kernel/smp.c
@@ -226,8 +226,7 @@ void show_ipi_stats(struct seq_file *p, int prec)
 	unsigned int cpu, i;
 
 	for (i = 0; i < IPI_MAX; i++) {
-		seq_printf(p, "%*s%u:%s", prec - 1, "IPI", i,
-			   prec >= 4 ? " " : "");
+		seq_printf(p, "%*s%u:", prec - 1, "IPI", i);
 		for_each_online_cpu(cpu)
 			seq_printf(p, "%10u ", irq_desc_kstat_cpu(ipi_desc[i], cpu));
 		seq_printf(p, " %s\n", ipi_names[i]);
diff --git a/arch/sh/kernel/irq.c b/arch/sh/kernel/irq.c
index 9022d8af9d686..03c39b5da50fb 100644
--- a/arch/sh/kernel/irq.c
+++ b/arch/sh/kernel/irq.c
@@ -46,7 +46,7 @@ int arch_show_interrupts(struct seq_file *p, int prec)
 	seq_printf(p, "%*s:", prec, "NMI");
 	for_each_online_cpu(j)
 		seq_put_decimal_ull_width(p, " ", per_cpu(irq_stat.__nmi_count, j), 10);
-	seq_printf(p, "  Non-maskable interrupts\n");
+	seq_printf(p, " Non-maskable interrupts\n");
 
 	seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count));
 
diff --git a/arch/sparc/kernel/irq_32.c b/arch/sparc/kernel/irq_32.c
index 5210991429d5e..22db727652ba2 100644
--- a/arch/sparc/kernel/irq_32.c
+++ b/arch/sparc/kernel/irq_32.c
@@ -199,19 +199,19 @@ int arch_show_interrupts(struct seq_file *p, int prec)
 	int j;
 
 #ifdef CONFIG_SMP
-	seq_printf(p, "RES:");
+	seq_printf(p, "%*s:", prec, "RES");
 	for_each_online_cpu(j)
 		seq_put_decimal_ull_width(p, " ", cpu_data(j).irq_resched_count, 10);
-	seq_printf(p, "     IPI rescheduling interrupts\n");
-	seq_printf(p, "CAL:");
+	seq_printf(p, " IPI rescheduling interrupts\n");
+	seq_printf(p, "%*s:", prec, "CAL");
 	for_each_online_cpu(j)
 		seq_put_decimal_ull_width(p, " ", cpu_data(j).irq_call_count, 10);
-	seq_printf(p, "     IPI function call interrupts\n");
+	seq_printf(p, " IPI function call interrupts\n");
 #endif
-	seq_printf(p, "NMI:");
+	seq_printf(p, "%*s:", prec, "NMI");
 	for_each_online_cpu(j)
 		seq_put_decimal_ull_width(p, " ", cpu_data(j).counter, 10);
-	seq_printf(p, "     Non-maskable interrupts\n");
+	seq_printf(p, " Non-maskable interrupts\n");
 	return 0;
 }
 
diff --git a/arch/sparc/kernel/irq_64.c b/arch/sparc/kernel/irq_64.c
index c5466a9fd5608..3f55c69d5f3bc 100644
--- a/arch/sparc/kernel/irq_64.c
+++ b/arch/sparc/kernel/irq_64.c
@@ -303,10 +303,10 @@ int arch_show_interrupts(struct seq_file *p, int prec)
 {
 	int j;
 
-	seq_printf(p, "NMI:");
+	seq_printf(p, "%*s:", prec, "NMI");
 	for_each_online_cpu(j)
 		seq_put_decimal_ull_width(p, " ", cpu_data(j).__nmi_count, 10);
-	seq_printf(p, "     Non-maskable interrupts\n");
+	seq_printf(p, " Non-maskable interrupts\n");
 	return 0;
 }
 
diff --git a/arch/um/kernel/irq.c b/arch/um/kernel/irq.c
index 5929d498b65fa..ddfd6e9bd8c77 100644
--- a/arch/um/kernel/irq.c
+++ b/arch/um/kernel/irq.c
@@ -716,12 +716,12 @@ int arch_show_interrupts(struct seq_file *p, int prec)
 	seq_printf(p, "%*s: ", prec, "RES");
 	for_each_online_cpu(cpu)
 		seq_printf(p, "%10u ", irq_stats(cpu)->irq_resched_count);
-	seq_puts(p, "  Rescheduling interrupts\n");
+	seq_puts(p, " Rescheduling interrupts\n");
 
 	seq_printf(p, "%*s: ", prec, "CAL");
 	for_each_online_cpu(cpu)
 		seq_printf(p, "%10u ", irq_stats(cpu)->irq_call_count);
-	seq_puts(p, "  Function call interrupts\n");
+	seq_puts(p, " Function call interrupts\n");
 #endif
 
 	return 0;
diff --git a/arch/xtensa/kernel/irq.c b/arch/xtensa/kernel/irq.c
index b1e410f6b5ab8..6f01f530868b0 100644
--- a/arch/xtensa/kernel/irq.c
+++ b/arch/xtensa/kernel/irq.c
@@ -59,7 +59,7 @@ int arch_show_interrupts(struct seq_file *p, int prec)
 	seq_printf(p, "%*s:", prec, "NMI");
 	for_each_online_cpu(cpu)
 		seq_printf(p, " %10lu", per_cpu(nmi_count, cpu));
-	seq_puts(p, "   Non-maskable interrupts\n");
+	seq_puts(p, " Non-maskable interrupts\n");
 #endif
 	return 0;
 }
diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c
index c635fb62c7837..1cb47a8eab498 100644
--- a/kernel/irq/proc.c
+++ b/kernel/irq/proc.c
@@ -460,7 +460,7 @@ int __weak arch_show_interrupts(struct seq_file *p, int prec)
 static struct irq_proc_constraints {
 	unsigned int	num_prec;
 } irq_proc_constraints __read_mostly = {
-	.num_prec	= 3,
+	.num_prec	= 4,
 };
 
 #ifndef ACTUAL_NR_IRQS
@@ -471,7 +471,7 @@ void irq_proc_calc_prec(void)
 {
 	unsigned int prec, n;
 
-	for (prec = 3, n = 1000; prec < 10 && n <= total_nr_irqs; ++prec)
+	for (prec = 4, n = 10000; prec < 10 && n <= total_nr_irqs; ++prec)
 		n *= 10;
 	WRITE_ONCE(irq_proc_constraints.num_prec, prec);
 }
diff --git a/scripts/gdb/linux/interrupts.py b/scripts/gdb/linux/interrupts.py
index a4e25d2bf123e..e96734348f860 100644
--- a/scripts/gdb/linux/interrupts.py
+++ b/scripts/gdb/linux/interrupts.py
@@ -131,23 +131,19 @@ def arm_common_show_interrupts(prec):
     if nr_ipi is None or ipi_desc is None or ipi_types is None:
         return text
 
-    if prec >= 4:
-        sep = " "
-    else:
-        sep = ""
-
     for ipi in range(nr_ipi):
-        text += "%*s%u:%s" % (prec - 1, "IPI", ipi, sep)
+        text += "%*s%u: " % (prec - 1, "IPI", ipi)
         desc = ipi_desc[ipi].cast(irq_desc_type.get_type().pointer())
         if desc == 0:
             continue
         for cpu in cpus.each_online_cpu():
-            text += "%10u" % (cpus.per_cpu(desc['kstat_irqs'], cpu)['cnt'])
-        text += "      %s" % (ipi_types[ipi].string())
+            text += "%10u " % (cpus.per_cpu(desc['kstat_irqs'], cpu)['cnt'])
+        text += "%s" % (ipi_types[ipi].string())
         text += "\n"
     return text
 
 def aarch64_show_interrupts(prec):
+    # Does not work for ARM64 as "ipi_desc" is not available there
     text = arm_common_show_interrupts(prec)
     text += "%*s: %10lu\n" % (prec, "ERR", gdb.parse_and_eval("irq_err_count"))
     return text
@@ -175,8 +171,8 @@ class LxInterruptList(gdb.Command):
 
     def invoke(self, arg, from_tty):
         nr_irqs = gdb.parse_and_eval("total_nr_irqs")
-        prec = 3
-        j = 1000
+        prec = 4
+        j = 10000
         while prec < 10 and j <= nr_irqs:
             prec += 1
             j *= 10