Re: [PATCH] scsi: Don't wait for completion of in-flight requests

From: Bart Van Assche
Date: Tue Nov 26 2024 - 08:50:31 EST


On 11/26/24 4:21 AM, John Garry wrote:
On 26/11/2024 11:50, Qiang Ma wrote:
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index adee6f60c966..0a2d5d9327fc 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -2065,7 +2065,7 @@ int scsi_mq_setup_tags(struct Scsi_Host *shost)
      tag_set->queue_depth = shost->can_queue;
      tag_set->cmd_size = cmd_size;
      tag_set->numa_node = dev_to_node(shost->dma_dev);
-    tag_set->flags = BLK_MQ_F_SHOULD_MERGE;
+    tag_set->flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_STACKING;

This should not be set for all SCSI hosts. Some SCSI hosts rely on bf0beec0607d.

Are there any SCSI hosts for which it is safe to set this flag? To me
the above change looks like a hack that should not be merged at all. Did
I perhaps overlook something?

Thanks,

Bart.