Re: [PATCH v3] storvsc: use small sg_tablesize on x86

James Bottomley
2016-06-09T17:26:12Z

On Thu, 2016-06-09 at 18:25 +0200, Olaf Hering wrote:
> Reducing the sg_tablesize allows booting of 32bit kernels in VMs,
> after
> commit be0cf6ca301c61458dc4aa1a37acf4f58d2ed3d6 ("scsi: storvsc: Set
> the
> tablesize based on the information given by the host")
>
> [ 5.567138] hv_storvsc vmbus_1: adjusting sg_tablesize 0x800 ->
> 0x20

Are you really sure 32 is the correct size? That caps transfers at 128
k. Even in the dim, dark, pre-64bit (at least on x86) days, our static
limit for sg tablesize was 128 (0.5M).

I know 32 it what it had before, but the reason for the commit you
quote was to improve performance ...

James