Merge tag 'irq-core-2026-06-13' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip

Pull interrupt core updates from Thomas Gleixner:

  - Rework of /proc/interrupt handling:

    /proc/interrupts was subject to micro optimizations for a long time,
    but most of the low hanging fruit was left on the table. This rework
    addresses the major time consuming issues:

      - Printing a long series of zeros one by one via a format string
        instead of counting subsequent zeros and emitting a string
        constant.

      - Simplify and cache the conditions whether interrupts should be
        printed

      - Use a proper iteration over the interrupt descriptor xarray
        instead of walking and testing one by one.

      - Provide helper functions for the architecture code to emit the
        architecture specific counters

      - Convert the counter structure in x86 to an array, which
        simplifies the output and add mechanisms to suppress unused
        architecture interrupts, which just occupy space for nothing.
        Adopt the new core mechanisms.

    This adjusts the gdb scripts related to interrupt counter statistics
    to work with the new mechanisms.

  - Prevent a string overflow in the /proc/irq/$N/ directory name
    creation code.

* tag 'irq-core-2026-06-13' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip:
  x86/irq: Add missing 's' back to thermal event printout
  genirq/proc: Speed up /proc/interrupts iteration
  genirq/proc: Runtime size the chip name
  genirq: Expose irq_find_desc_at_or_after() in core code
  genirq: Add rcuref count to struct irq_desc
  genirq/proc: Increase default interrupt number precision to four
  genirq: Calculate precision only when required
  genirq: Cache the condition for /proc/interrupts exposure
  genirq/manage: Make NMI cleanup RT safe
  genirq: Expose nr_irqs in core code
  scripts/gdb: Update x86 interrupts to the array based storage
  x86/irq: Move IOAPIC misrouted and PIC/APIC error counts into irq_stats
  x86/irq: Suppress unlikely interrupt stats by default
  x86/irq: Make irqstats array based
  genirq/proc: Utilize irq_desc::tot_count to avoid evaluation
  genirq/proc: Avoid formatting zero counts in /proc/interrupts
  x86/irq: Optimize interrupts decimals printing
  genirq/proc: Size interrupt directory names for 10-digit interrupt numbers

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)
@@ -48,7 +48,7 @@ def show_irq_desc(prec, irq):
             count = cpus.per_cpu(desc['kstat_irqs'], cpu)['cnt']
         else:
             count = 0
-        text += "%10u" % (count)
+        text += "%10u " % (count)
 
     name = "None"
     if desc['irq_data']['chip']:
@@ -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'])
@@ -97,64 +97,29 @@ def show_irq_err_count(prec):
         text += "%*s: %10u\n" % (prec, "ERR", cnt['counter'])
     return text
 
-def x86_show_irqstat(prec, pfx, field, desc):
-    irq_stat = gdb.parse_and_eval("&irq_stat")
+def x86_show_irqstat(prec, pfx, idx, desc):
+    irq_stat = gdb.parse_and_eval("&irq_stat.counts[%d]" %idx)
     text = "%*s: " % (prec, pfx)
     for cpu in cpus.each_online_cpu():
         stat = cpus.per_cpu(irq_stat, cpu)
-        text += "%10u " % (stat[field])
-    text += "  %s\n" % (desc)
-    return text
-
-def x86_show_mce(prec, var, pfx, desc):
-    pvar = gdb.parse_and_eval(var)
-    text = "%*s: " % (prec, pfx)
-    for cpu in cpus.each_online_cpu():
-        text += "%10u " % (cpus.per_cpu(pvar, cpu).dereference())
-    text += "  %s\n" % (desc)
+        text += "%10u " % (stat.dereference())
+    text += desc
     return text
 
 def x86_show_interupts(prec):
-    text = x86_show_irqstat(prec, "NMI", '__nmi_count', 'Non-maskable interrupts')
+    info_type = gdb.lookup_type('struct irq_stat_info')
+    info = gdb.parse_and_eval('irq_stat_info')
+    bitmap = gdb.parse_and_eval('irq_stat_count_show')
+    bitsperlong = 8 * int(bitmap.type.target().sizeof)
 
-    if constants.LX_CONFIG_X86_LOCAL_APIC:
-        text += x86_show_irqstat(prec, "LOC", 'apic_timer_irqs', "Local timer interrupts")
-        text += x86_show_irqstat(prec, "SPU", 'irq_spurious_count', "Spurious interrupts")
-        text += x86_show_irqstat(prec, "PMI", 'apic_perf_irqs', "Performance monitoring interrupts")
-        text += x86_show_irqstat(prec, "IWI", 'apic_irq_work_irqs', "IRQ work interrupts")
-        text += x86_show_irqstat(prec, "RTR", 'icr_read_retry_count', "APIC ICR read retries")
-        if utils.gdb_eval_or_none("x86_platform_ipi_callback") is not None:
-            text += x86_show_irqstat(prec, "PLT", 'x86_platform_ipis', "Platform interrupts")
-
-    if constants.LX_CONFIG_SMP:
-        text += x86_show_irqstat(prec, "RES", 'irq_resched_count', "Rescheduling interrupts")
-        text += x86_show_irqstat(prec, "CAL", 'irq_call_count', "Function call interrupts")
-        text += x86_show_irqstat(prec, "TLB", 'irq_tlb_count', "TLB shootdowns")
-
-    if constants.LX_CONFIG_X86_THERMAL_VECTOR:
-        text += x86_show_irqstat(prec, "TRM", 'irq_thermal_count', "Thermal events interrupts")
-
-    if constants.LX_CONFIG_X86_MCE_THRESHOLD:
-        text += x86_show_irqstat(prec, "THR", 'irq_threshold_count', "Threshold APIC interrupts")
-
-    if constants.LX_CONFIG_X86_MCE_AMD:
-        text += x86_show_irqstat(prec, "DFR", 'irq_deferred_error_count', "Deferred Error APIC interrupts")
-
-    if constants.LX_CONFIG_X86_MCE:
-        text += x86_show_mce(prec, "&mce_exception_count", "MCE", "Machine check exceptions")
-        text += x86_show_mce(prec, "&mce_poll_count", "MCP", "Machine check polls")
-
-    text += show_irq_err_count(prec)
-
-    if constants.LX_CONFIG_X86_IO_APIC:
-        cnt = utils.gdb_eval_or_none("irq_mis_count")
-        if cnt is not None:
-            text += "%*s: %10u\n" % (prec, "MIS", cnt['counter'])
-
-    if constants.LX_CONFIG_KVM:
-        text += x86_show_irqstat(prec, "PIN", 'kvm_posted_intr_ipis', 'Posted-interrupt notification event')
-        text += x86_show_irqstat(prec, "NPI", 'kvm_posted_intr_nested_ipis', 'Nested posted-interrupt event')
-        text += x86_show_irqstat(prec, "PIW", 'kvm_posted_intr_wakeup_ipis', 'Posted-interrupt wakeup event')
+    text = ""
+    for idx in range(int(info.type.sizeof / info_type.sizeof)):
+        show = bitmap[int(idx / bitsperlong)]
+        if not show & 1 << int(idx % bitsperlong):
+            continue
+        pfx = info[idx]['symbol'].string()
+        desc = info[idx]['text'].string()
+        text += x86_show_irqstat(prec, pfx, idx, desc)
 
     return text
 
@@ -166,23 +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
@@ -209,12 +170,19 @@ class LxInterruptList(gdb.Command):
         super(LxInterruptList, self).__init__("lx-interruptlist", gdb.COMMAND_DATA)
 
     def invoke(self, arg, from_tty):
-        nr_irqs = gdb.parse_and_eval("nr_irqs")
-        prec = 3
-        j = 1000
-        while prec < 10 and j <= nr_irqs:
-            prec += 1
-            j *= 10
+        nr_irqs = gdb.parse_and_eval("total_nr_irqs")
+        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():
@@ -225,7 +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))