Re: This is the fourth time I’ve tried to find what led to the regression of outgoing network speed and each time I find the merge commit 8c94ccc7cd691472461448f98e2372c75849406c

[Mathias Nyman]

On 5.2.2024 23.08, Mikhail Gavrilov wrote:
> On Mon, Feb 5, 2024 at 1:47 AM Christian A. Ehrhardt <lk@xxxxxxx> wrote:
>
> Thanks for real help.
> Now I spotted a really bad commit.
>
> 57e153dfd0e7a080373fe5853c5609443d97fa5a is the first bad commit
> commit 57e153dfd0e7a080373fe5853c5609443d97fa5a
> Author: Niklas Neronin <niklas.neronin@xxxxxxxxxxxxxxx>
> Date:   Fri Dec 1 17:06:40 2023 +0200
>
>      xhci: add handler for only one interrupt line
>
>      Current xHCI driver only supports one "interrupter", meaning we will
>      only use one MSI/MSI-X interrupt line. Thus, add handler only to the
>      first interrupt line.
>
>      Signed-off-by: Niklas Neronin <niklas.neronin@xxxxxxxxxxxxxxx>
>      Co-developed-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
>      Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
>      Link: https://lore.kernel.org/r/20231201150647.1307406-13-mathias.nyman@xxxxxxxxxxxxxxx
>      Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
>
>   drivers/usb/host/xhci-pci.c | 35 ++++++++++-------------------------
>   1 file changed, 10 insertions(+), 25 deletions(-)
>
> Niklas, Mathias I spotted decreased network speed on sending when
> transferring files via sftp between my workstations in the local
> network.
> And bisection of issue leads me to this commit.
> My motherboard is MPG-B650I-EDGE-WIFI looks like it is related to the
> mentioned commit.
> https://www.msi.com/Motherboard/MPG-B650I-EDGE-WIFI

This seems odd, not sure how this usb host change would impact your network speed.

Could you try reverting that patch from 6.8-rc1 and see if it helps?

There are some other patches on top of it that needs to be reverted first.
These should be enough:

36b24ebf9a04 xhci: minor coding style cleanup in 'xhci_try_enable_msi()
9831960df237 xhci: rework 'xhci_try_enable_msi()' MSI and MSI-X setup code
dfbf4441f2d3 xhci: change 'msix_count' to encompass MSI or MSI-X vectors
a795f708b284 xhci: refactor static MSI function
74554e9c2276 xhci: refactor static MSI-X function
f977f4c9301c xhci: add handler for only one interrupt line

That patch changes how we request MSI/MSI-X interrupt(s) for xhci.

Is there any change is /proc/interrupts between a good and bad case?
Such as xhci_hcd using MSI-X instead of MSI, or eth0 and xhci_hcd
interrupting on the same CPU?

Thanks
Mathias