From 33b1e95c90447ea73e37e837ea0268a894919f19 Mon Sep 17 00:00:00 2001
From: Keith Busch <keith.busch@intel.com>
Date: Mon, 24 Mar 2014 10:46:26 -0600
Subject: [PATCH] NVMe: CPU hot plug notification
Registers with hot cpu notification to rebalance, and potentially allocate
additional, io queues.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
---
drivers/block/nvme-core.c | 19 +++++++++++++++++++
include/linux/nvme.h | 1 +
2 files changed, 20 insertions(+)
diff --git a/drivers/block/nvme-core.c b/drivers/block/nvme-core.c
index 48d7bd55207a..ce5a4f1a3950 100644
--- a/drivers/block/nvme-core.c
+++ b/drivers/block/nvme-core.c
@@ -2002,6 +2002,19 @@ static size_t db_bar_size(struct nvme_dev *dev, unsigned nr_io_queues)
return 4096 + ((nr_io_queues + 1) * 8 * dev->db_stride);
}
+static int nvme_cpu_notify(struct notifier_block *self,
+ unsigned long action, void *hcpu)
+{
+ struct nvme_dev *dev = container_of(self, struct nvme_dev, nb);
+ switch (action) {
+ case CPU_ONLINE:
+ case CPU_DEAD:
+ nvme_assign_io_queues(dev);
+ break;
+ }
+ return NOTIFY_OK;
+}
+
static int nvme_setup_io_queues(struct nvme_dev *dev)
{
struct nvme_queue *adminq = raw_nvmeq(dev, 0);
@@ -2080,6 +2093,11 @@ static int nvme_setup_io_queues(struct nvme_dev *dev)
nvme_free_queues(dev, nr_io_queues + 1);
nvme_assign_io_queues(dev);
+ dev->nb.notifier_call = &nvme_cpu_notify;
+ result = register_hotcpu_notifier(&dev->nb);
+ if (result)
+ goto free_queues;
+
return 0;
free_queues:
@@ -2357,6 +2375,7 @@ static void nvme_dev_shutdown(struct nvme_dev *dev)
int i;
dev->initialized = 0;
+ unregister_hotcpu_notifier(&dev->nb);
spin_lock(&dev_list_lock);
list_del_init(&dev->node);
diff --git a/include/linux/nvme.h b/include/linux/nvme.h
index f0f95c719685..15d071eba8b8 100644
--- a/include/linux/nvme.h
+++ b/include/linux/nvme.h
@@ -92,6 +92,7 @@ struct nvme_dev {
struct kref kref;
struct miscdevice miscdev;
struct work_struct reset_work;
+ struct notifier_block nb;
char name[12];
char serial[20];
char model[40];
--
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