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

From: Mikhail Gavrilov
Date: Fri Feb 02 2024 - 20:02:38 EST


Hi,
I'm trying to find the first bad commit that led to a decreased
network outgoing speed.
And every time I come to a huge merge [Merge tag 'usb-6.8-rc1' of
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb]
I have already triple-checked all my answers and speed measurements.
I don't understand where I'm making a mistake.

Let's try to figure it out together.

Input data:
Two computers connected 1Gbps link.
Both have the same hardware.
Network: RTL8125 2.5GbE Controller (rev 05)

When I copy files from one computer to another and kernel snapshot
builded from commit 296455ade1fd I have 97-110MB/sec which is almost
max speed of 1Gbps link.
When I move to commit 9d1694dc91ce I have only 66-70MB/sec which is
significantly slower.

I bisected the issue by measuring network speed on each step.
I save all results to file [1]

[1] file is attached as a zip archive.

# first bad commit: [8c94ccc7cd691472461448f98e2372c75849406c] Merge
tag 'usb-6.8-rc1' of
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb

--
Best Regards,
Mike Gavrilov.

Attachment: speed-measure.zip
Description: Zip archive