Re: [PATCH 4.19 114/149] UAS: Revert commit 3ae62a42090f ("UAS: fix alignment of scatter/gather segments")

[Oliver Neukum]

Am Dienstag, den 05.11.2019, 10:09 -0500 schrieb Alan Stern:
> On Tue, 5 Nov 2019, Oliver Neukum wrote:
> 
> > Am Montag, den 04.11.2019, 22:45 +0100 schrieb Greg Kroah-Hartman:
> > >         Since commit ea44d190764b ("usbip: Implement SG support to
> > >         vhci-hcd and stub driver") was merged, the USB/IP driver can
> > >         also handle SG.
> > 
> > Hi,
> > 
> > same story as 4.4.x
> 
> I'm not sure about uas, but it was reported just yesterday that the 
> corresponding commit for usb-storage caused a 30% speed degradation:
> 
> 	https://marc.info/?l=linux-usb&m=157293660212040&w=2
> 
> Given this information, perhaps you will decide that the revert is 
> worthwhile.

Damned if I do, damned if I do not.
Check for usbip and special case it?

	Regards
		Oliver