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authorMichael Kelley (EOSG) <Michael.H.Kelley@microsoft.com>2018-01-24 23:14:08 +0100
committerMartin K. Petersen <martin.petersen@oracle.com>2018-02-22 04:30:40 +0100
commit9cfad4a5f4f795715c8657fb7dc22574a6046327 (patch)
tree08f6d2f014c10bd27510c79dccf346f89ca3cc57
parentscsi: megaraid_sas: Do not use 32-bit atomic request descriptor for Ventura c... (diff)
downloadlinux-9cfad4a5f4f795715c8657fb7dc22574a6046327.tar.xz
linux-9cfad4a5f4f795715c8657fb7dc22574a6046327.zip
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 <mikelley@microsoft.com> Reviewed-by: Long Li <longli@microsoft.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
-rw-r--r--drivers/scsi/storvsc_drv.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index 8eadb30115aa..620510787763 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];