From: Michael Kelley (EOSG) Date: Wed, 24 Jan 2018 22:14:08 +0000 (+0000) Subject: scsi: storvsc: Spread interrupts when picking a channel for I/O requests X-Git-Tag: v4.19~1382^2~24 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=9cfad4a5f4f795715c8657fb7dc22574a6046327;p=platform%2Fkernel%2Flinux-rpi.git scsi: storvsc: Spread interrupts when picking a channel for I/O requests Update the algorithm in storvsc_do_io to look for a channel starting with the current CPU + 1 and wrap around (within the current NUMA node). This spreads VMbus interrupts more evenly across CPUs. Previous code always started with first CPU in the current NUMA node, skewing the interrupt load to that CPU. Signed-off-by: Michael Kelley Reviewed-by: Long Li Signed-off-by: Martin K. Petersen --- diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c index 8eadb30..6205107 100644 --- a/drivers/scsi/storvsc_drv.c +++ b/drivers/scsi/storvsc_drv.c @@ -1310,7 +1310,8 @@ static int storvsc_do_io(struct hv_device *device, */ cpumask_and(&alloced_mask, &stor_device->alloced_cpus, cpumask_of_node(cpu_to_node(q_num))); - for_each_cpu(tgt_cpu, &alloced_mask) { + for_each_cpu_wrap(tgt_cpu, &alloced_mask, + outgoing_channel->target_cpu + 1) { if (tgt_cpu != outgoing_channel->target_cpu) { outgoing_channel = stor_device->stor_chns[tgt_cpu];