Messages in this thread | | | Subject | Re: [PATCH] scsi: storvsc: Cap scsi_driver.can_queue to fix a hang issue during boot | From | John Garry <> | Date | Wed, 6 Oct 2021 17:24:00 +0100 |
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On 06/10/2021 17:08, Michael Kelley wrote: >>> The calculated value of can_queue is not realistic. The blk-mq layer >>> caps the number of tags at 10240, >> nit: 1024, I think > I was thinking about BLK_MQ_MAX_DEPTH (#define'd as 10240), which > is used to limit the tag set size in blk_mq_alloc_tag_set(). When running > on large VMs on Hyper-V, we can see the "blk-mq: reduced tag depth > to 10240" message.:-(
Ah, right. The other related capping is the sdev queue depth, which is now capped at max(1024, can_queue), see scsi_device_max_queue_depth().
Thanks, John
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