[PATCH 4.14 197/496] nvme: pci: pass max vectors as num_possible_cpus() to pci_alloc_irq_vectors

From: Greg Kroah-Hartman
Date: Mon May 28 2018 - 09:18:07 EST


4.14-stable review patch. If anyone has any objections, please let me know.

------------------

From: Ming Lei <ming.lei@xxxxxxxxxx>

[ Upstream commit 16ccfff2897613007b5eda9e29d65303c6280026 ]

84676c1f21 ("genirq/affinity: assign vectors to all possible CPUs")
has switched to do irq vectors spread among all possible CPUs, so
pass num_possible_cpus() as max vecotrs to be assigned.

For example, in a 8 cores system, 0~3 online, 4~8 offline/not present,
see 'lscpu':

[ming@box]$lscpu
Architecture: x86_64
CPU op-mode(s): 32-bit, 64-bit
Byte Order: Little Endian
CPU(s): 4
On-line CPU(s) list: 0-3
Thread(s) per core: 1
Core(s) per socket: 2
Socket(s): 2
NUMA node(s): 2
...
NUMA node0 CPU(s): 0-3
NUMA node1 CPU(s):
...

1) before this patch, follows the allocated vectors and their affinity:
irq 47, cpu list 0,4
irq 48, cpu list 1,6
irq 49, cpu list 2,5
irq 50, cpu list 3,7

2) after this patch, follows the allocated vectors and their affinity:
irq 43, cpu list 0
irq 44, cpu list 1
irq 45, cpu list 2
irq 46, cpu list 3
irq 47, cpu list 4
irq 48, cpu list 6
irq 49, cpu list 5
irq 50, cpu list 7

Cc: Keith Busch <keith.busch@xxxxxxxxx>
Cc: Sagi Grimberg <sagi@xxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Keith Busch <keith.busch@xxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/nvme/host/pci.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -1770,7 +1770,7 @@ static int nvme_setup_io_queues(struct n
int result, nr_io_queues;
unsigned long size;

- nr_io_queues = num_present_cpus();
+ nr_io_queues = num_possible_cpus();
result = nvme_set_queue_count(&dev->ctrl, &nr_io_queues);
if (result < 0)
return result;