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authorLinus Torvalds <torvalds@linux-foundation.org>2017-07-30 11:27:33 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-07-30 11:27:33 -0700
commit06efc7df376659963ba4de26217ebdcdc2a6c09b (patch)
tree3fc53f8863d3c04765f52f81209d072237e62f4a
parent0a07b238e5f488b459b6113a62e06b6aab017f71 (diff)
parent8397913303abc9333f376a518a8368fa22ca5e6e (diff)
Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fix from Thomas Gleixner: "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" * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: genirq/cpuhotplug: Revert "Set force affinity flag on hotplug migration"
-rw-r--r--include/linux/irq.h7
-rw-r--r--kernel/irq/cpuhotplug.c9
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);