Linus,
please pull the latest irq-urgent-for-linus git tree from:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git
irq-urgent-for-linus
Fix for a regression caused by the conversion of x86 to the generic hotplug
code. Instead of doing a plain single line revert, this adds a pile of
comments so the semantics of the force argument are clear.
Thanks,
tglx
------------------>
Thomas Gleixner (1):
genirq/cpuhotplug: Revert "Set force affinity flag on hotplug migration"
include/linux/irq.h | 7 ++++++-
kernel/irq/cpuhotplug.c | 9 +++++++--
2 files changed, 13 insertions(+), 3 deletions(-)
diff --git a/include/linux/irq.h b/include/linux/irq.h
index 00db35b61e9e..d2d543794093 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -388,7 +388,12 @@ static inline irq_hw_number_t irqd_to_hwirq(struct
irq_data *d)
* @irq_mask_ack: ack and mask an interrupt source
* @irq_unmask: unmask an interrupt source
* @irq_eoi: end of interrupt
- * @irq_set_affinity: set the CPU affinity on SMP machines
+ * @irq_set_affinity: Set the CPU affinity on SMP machines. If the force
+ * argument is true, it tells the driver to
+ * unconditionally apply the affinity setting. Sanity
+ * checks against the supplied affinity mask are not
+ * required. This is used for CPU hotplug where the
+ * target CPU is not yet set in the cpu_online_mask.
* @irq_retrigger: resend an IRQ to the CPU
* @irq_set_type: set the flow type (IRQ_TYPE_LEVEL/etc.) of an IRQ
* @irq_set_wake: enable/disable power-management wake-on of an IRQ
diff --git a/kernel/irq/cpuhotplug.c b/kernel/irq/cpuhotplug.c
index aee8f7ec40af..638eb9c83d9f 100644
--- a/kernel/irq/cpuhotplug.c
+++ b/kernel/irq/cpuhotplug.c
@@ -95,8 +95,13 @@ static bool migrate_one_irq(struct irq_desc *desc)
affinity = cpu_online_mask;
brokeaff = true;
}
-
- err = irq_do_set_affinity(d, affinity, true);
+ /*
+ * Do not set the force argument of irq_do_set_affinity() as this
+ * disables the masking of offline CPUs from the supplied affinity
+ * mask and therefore might keep/reassign the irq to the outgoing
+ * CPU.
+ */
+ err = irq_do_set_affinity(d, affinity, false);
if (err) {
pr_warn_ratelimited("IRQ%u: set affinity failed(%d).\n",
d->irq, err);
