Re: [PATCH v2 4.19 0/4] ext4: improve delalloc buffer write performance

[Greg KH <gregkh@linuxfoundation.org>]

On Wed, Jul 24, 2024 at 12:55:52PM +0800, WangYuli wrote:
> Hi greg k-h,
> 
> As a commercial Linux distribution maintainer, we understand that
> even though upstream support for linux-4.19.y is ending, our users'
> reliance on this kernel version will not cease immediately.

Good luck to them, given that almost immediately after it goes out of
support it will become insecure :(

> They often lack the time or resources to promptly migrate all their
> devices to a newer kernel, due to considerations such as stability,
> operational costs, and other factors.

They have had 6 years to plan for this, how much time do they need?

> Therefore, to provide a more graceful conclusion to the linux-4.19.y
> lifecycle, we propose backporting these performance optimizations
> to extend its useful life  and ensure a smooth transition for commercial
> users by the way.

Performance optimizations for old kernels like this are not a good idea,
please just have them move to a more modern, and actually supported,
kernel instead if they wish to have performance improvements.  Otherwise
you are ensuring they will never move.

good luck!

greg k-h