genirq/proc: Runtime size the chip name

The chip name column in the /proc/interrupt output is 8 characters and
right aligned, which causes visual clutter due to the fixed length and the
alignment. Many interrupt chips, e.g. PCI/MSI[X] have way longer names.

Update the length when a chip is assigned to an interrupt and utilize this
information for the output. Align it left so all chip names start at the
begin of the column.

Update the GDB script as well and disentangle the header maze so it
actually works with all .config combinations.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Dmitry Ilvokhin <d@ilvokhin.com>
Link: https://patch.msgid.link/20260517194932.085786035@kernel.org

1 files changed, 15 insertions, 8 deletions

diff --git a/scripts/gdb/linux/interrupts.py b/scripts/gdb/linux/interrupts.py
index e96734348f86..a68ae91b4531 100644
--- a/scripts/gdb/linux/interrupts.py
+++ b/scripts/gdb/linux/interrupts.py
@@ -20,7 +20,7 @@ def irq_desc_is_chained(desc):
 def irqd_is_level(desc):
     return desc['irq_data']['common']['state_use_accessors'] & constants.LX_IRQD_LEVEL
 
-def show_irq_desc(prec, irq):
+def show_irq_desc(prec, chip_width, irq):
     text = ""
 
     desc = mapletree.mtree_load(gdb.parse_and_eval("&sparse_irqs"), irq)
@@ -58,7 +58,7 @@ def show_irq_desc(prec, irq):
         else:
             name = "-"
 
-    text += "  %-8s" % (name)
+    text += "  %-*s" % (chip_width, name)
 
     if desc['irq_data']['domain']:
         text += "  %*lu" % (prec, desc['irq_data']['hwirq'])
@@ -171,11 +171,18 @@ class LxInterruptList(gdb.Command):
 
     def invoke(self, arg, from_tty):
         nr_irqs = gdb.parse_and_eval("total_nr_irqs")
-        prec = 4
-        j = 10000
-        while prec < 10 and j <= nr_irqs:
-            prec += 1
-            j *= 10
+        constr = utils.gdb_eval_or_none('irq_proc_constraints')
+
+        if constr:
+            prec = int(constr['num_prec'])
+            chip_width = int(constr['chip_width'])
+        else:
+            prec = 4
+            j = 10000
+            while prec < 10 and j <= nr_irqs:
+                prec += 1
+                j *= 10
+            chip_width = 8
 
         gdb.write("%*s" % (prec + 8, ""))
         for cpu in cpus.each_online_cpu():
@@ -186,7 +193,7 @@ class LxInterruptList(gdb.Command):
             raise gdb.GdbError("Unable to find the sparse IRQ tree, is CONFIG_SPARSE_IRQ enabled?")
 
         for irq in range(nr_irqs):
-            gdb.write(show_irq_desc(prec, irq))
+            gdb.write(show_irq_desc(prec, chip_width, irq))
         gdb.write(arch_show_interrupts(prec))