Messages in this thread | | | Date | Sat, 15 Mar 2014 11:13:22 -0400 | From | Theodore Ts'o <> | Subject | Re: [PATCH] virtio-blk: make the queue depth the max supportable by the hypervisor |
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On Sat, Mar 15, 2014 at 06:57:23AM -0700, Christoph Hellwig wrote: > I don't think this should be a module parameter. The default sizing > should be based of the parameters of the actual virtqueue, and if we > want to allow tuning it it should be by a sysfs attribute, preferable > using the same semantics as SCSI.
I wanted that too, but looking at the multiqueue code, it wasn't all obvious how to safely adjust the queue depth once the virtio-blk device driver is initialized and becomes active. There are all sorts data structures including bitmaps, etc. that would have to be resized, and I decided it would be too difficult / risky for me to make it be dynamically resizeable.
So I settled on a module parameter thinking it would mostly only used by testers / benchmarkers.
Can someone suggest a way to do a dynamic resizing of the virtio-blk queue depth easily / safely?
- Ted
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