Bug#836734: Considerable I/O performance regression on Lenovo Carbon X1 with 4.7.0

[Salvatore Bonaccorso <carnil@debian.org>]

Control: tags -1 + moreinfo

Hi Yuri,

On Mon, Sep 05, 2016 at 12:27:04PM +0200, Yuri D'Elia wrote:
> Package: src:linux
> Version: 4.7.2-1
> Severity: normal
> 
> I'm using a Carbon X1 (3rd gen). Compared to the latest 4.6 kernel, this image
> has a significant performance regression in all I/O related operations.
> 
> Just as a ballpark, 4.6.0-1 can boot in generally less than 3 seconds after the
> grub screen. With 4.7.0-1, it takes over 10.
> 
> I'm unsure at what exactly look for, as it could also be related to many
> subsystems (I'm using an ext4 fs in an encrypted volume).

I was seeing similar issues with a X1 laptop after the update of 4.6.x
to 4.7.x, and seem dissapeared with the update to 4.8.5-1. I was
unable to deduce though the introducing change for this regression.

Regards,
Salvatore