On 8/24/2026 5:45 AM, Wei Liu wrote:
On Tue, Jul 28, 2026 at 01:51:16PM +0000, Naman Jain wrote:
fixup_irqs() re-injects a pending interrupt on its new target CPU by
looking at the outermost domain chip and invoking its irq_retrigger()
callback directly. That only works when the outermost chip happens to
install an irq_retrigger() callback, which is not guaranteed for every
irqchip and could lead to lost interrupts on CPU hot-unplug.
Use irq_chip_retrigger_hierarchy() instead, which walks up the interrupt
hierarchy until it finds a chip that implements irq_retrigger().
While at it, move the loop-local variables into the loop scope and use a
scoped guard for desc->lock.
No functional change intended for chips which already provide an
irq_retrigger() callback on the outermost domain.
Suggested-by: Thomas Gleixner <[email protected]>
Signed-off-by: Naman Jain <[email protected]>
I can pick this up as part of this series but this requires an ack from
Thomas.
Wei
Hi Wei,
Patch 1 that you picked is same in v1, v2, so that is fine.
But there's v2 for this series, where the rest of the patches are being
discussed.
https://lore.kernel.org/all/[email protected]/
Regards,
Naman
---
arch/x86/kernel/irq.c | 23 +++++++----------------
1 file changed, 7 insertions(+), 16 deletions(-)
diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index 30122f0b3af96..ef1bdd3c4659a 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -466,11 +466,6 @@ DEFINE_IDTENTRY_SYSVEC(sysvec_posted_msi_notification)
/* A cpu has been removed from cpu_online_mask. Reset irq affinities. */
void fixup_irqs(void)
{
- unsigned int vector;
- struct irq_desc *desc;
- struct irq_data *data;
- struct irq_chip *chip;
-
irq_migrate_all_off_this_cpu();
/*
@@ -489,22 +484,18 @@ void fixup_irqs(void)
* vector_lock because the cpu is already marked !online, so
* nothing else will touch it.
*/
- for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; vector++) {
- if (IS_ERR_OR_NULL(__this_cpu_read(vector_irq[vector])))
+ for (unsigned int vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS;
vector++) {
+ struct irq_desc *desc = __this_cpu_read(vector_irq[vector]);
+
+ if (IS_ERR_OR_NULL(desc))
continue;
if (is_vector_pending(vector)) {
- desc = __this_cpu_read(vector_irq[vector]);
-
- raw_spin_lock(&desc->lock);
- data = irq_desc_get_irq_data(desc);
- chip = irq_data_get_irq_chip(data);
- if (chip->irq_retrigger) {
- chip->irq_retrigger(data);
+ guard(raw_spinlock)(&desc->lock);
+ if (irq_chip_retrigger_hierarchy(&desc->irq_data))
__this_cpu_write(vector_irq[vector],
VECTOR_RETRIGGERED);
- }
- raw_spin_unlock(&desc->lock);
}
+
if (__this_cpu_read(vector_irq[vector]) != VECTOR_RETRIGGERED)
__this_cpu_write(vector_irq[vector], VECTOR_UNUSED);
}
--
2.43.0
