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

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.

Alan Stern