Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.debian.kernel > #89842 > unrolled thread

Request to consider backporting EPYC VM performance patch to Debian 11 (kernel 5.10)

Back to article view | Back to linux.debian.kernel

Contents

  Request to consider backporting EPYC VM performance patch to Debian  11 (kernel 5.10) Cody Zuschlag <cody.zuschlag@xenproject.org> - 2025-10-31 12:20 +0100
    Re: Request to consider backporting EPYC VM performance patch to  Debian 11 (kernel 5.10) Cody Zuschlag <cody.zuschlag@xenproject.org> - 2025-11-13 17:10 +0100
      Re: Request to consider backporting EPYC VM performance patch to  Debian 11 (kernel 5.10) Salvatore Bonaccorso <carnil@debian.org> - 2025-11-14 22:50 +0100
    Re: Request to consider backporting EPYC VM performance patch to  Debian 11 (kernel 5.10) Bastian Blank <waldi@debian.org> - 2025-11-13 17:50 +0100

#89842 — Request to consider backporting EPYC VM performance patch to Debian 11 (kernel 5.10)

[Multipart message — attachments visible in raw view] — view raw

Hello Debian Kernel Team,

I'm the Community Manager for the Xen Project. I'm writing on behalf of the
Xen Project community regarding a Linux kernel patch that improves
virtual-machine performance on AMD EPYC systems running Xen or KVM (with
Xen emulation).

The patch addresses a communication-performance issue between VMs on the
same host. A workaround already exists downstream, but inclusion in Debian
11’s 5.10 kernel would ensure stable performance without manual
adjustments. Greg KH declined to backport the series to 5.10 stable as it’s
a performance improvement rather than a bug fix, but it has proven reliable
in testing.

Patch reference:
- Mainline patch by Juergen Gross (SUSE)
<https://lore.kernel.org/all/20220530082634.6339-1-jgross@suse.com/>
or its backport:
- Backport by Teddy Astie (Vates)
<https://lore.kernel.org/all/4cc9c1f583fb4bfca02ff7050b9b01cb9abb7e7f.1756803599.git.teddy.astie@vates.tech/>

Would you consider integrating this patch into Debian 11’s kernel?
Please let us know if you prefer that we open a bug for tracking.

Very best regards,

Cody Zuschlag
Xen Project - Community Manager

[toc] | [next] | [standalone]

#90014 — Re: Request to consider backporting EPYC VM performance patch to Debian 11 (kernel 5.10)

[Multipart message — attachments visible in raw view] — view raw

Hello again,

Just a gentle follow-up on the request below about the EPYC VM performance
patch for Debian 11’s 5.10 kernel.

If this is something you’d consider, I’m happy to open a bug against the
linux source package and track it there, or provide more details about the
Xen/XCP-ng side and performance impact on AMD EPYC systems running Xen or
KVM (with Xen emulation).

Please let me know what the preferred next step would be.

Best regards,


Cody Zuschlag
Xen Project - Community Manager


On Fri, Oct 31, 2025 at 11:33 AM Cody Zuschlag <cody.zuschlag@xenproject.org>
wrote:

> Hello Debian Kernel Team,
>
> I'm the Community Manager for the Xen Project. I'm writing on behalf of
> the Xen Project community regarding a Linux kernel patch that improves
> virtual-machine performance on AMD EPYC systems running Xen or KVM (with
> Xen emulation).
>
> The patch addresses a communication-performance issue between VMs on the
> same host. A workaround already exists downstream, but inclusion in Debian
> 11’s 5.10 kernel would ensure stable performance without manual
> adjustments. Greg KH declined to backport the series to 5.10 stable as it’s
> a performance improvement rather than a bug fix, but it has proven reliable
> in testing.
>
> Patch reference:
> - Mainline patch by Juergen Gross (SUSE)
> <https://lore.kernel.org/all/20220530082634.6339-1-jgross@suse.com/>
> or its backport:
> - Backport by Teddy Astie (Vates)
> <https://lore.kernel.org/all/4cc9c1f583fb4bfca02ff7050b9b01cb9abb7e7f.1756803599.git.teddy.astie@vates.tech/>
>
> Would you consider integrating this patch into Debian 11’s kernel?
> Please let us know if you prefer that we open a bug for tracking.
>
> Very best regards,
>
> Cody Zuschlag
> Xen Project - Community Manager
>

[toc] | [prev] | [next] | [standalone]

#90040 — Re: Request to consider backporting EPYC VM performance patch to Debian 11 (kernel 5.10)

Hi,

On Thu, Nov 13, 2025 at 04:48:31PM +0100, Cody Zuschlag wrote:
> Hello again,
> 
> Just a gentle follow-up on the request below about the EPYC VM performance
> patch for Debian 11’s 5.10 kernel.
> 
> If this is something you’d consider, I’m happy to open a bug against the
> linux source package and track it there, or provide more details about the
> Xen/XCP-ng side and performance impact on AMD EPYC systems running Xen or
> KVM (with Xen emulation).
> 
> Please let me know what the preferred next step would be.

The final word is on Ben, but you really want to make this be accepted
by upstream stable maintainers, as Debian follows the stable series
for 5.10.y so picks up any fixes there.

In particular if this is an area which will be frequently touched is
not an option to need to rebase on each new upstream import a
patchset.

That said, I cannot say if for the 5.10.y kernel and bullseye (which
is LTS now) an exception could be considered here. 

Ben, comments?

Regards,
Salvatore

[toc] | [prev] | [next] | [standalone]

#90015 — Re: Request to consider backporting EPYC VM performance patch to Debian 11 (kernel 5.10)

On Fri, Oct 31, 2025 at 11:33:11AM +0100, Cody Zuschlag wrote:
> Would you consider integrating this patch into Debian 11’s kernel?
> Please let us know if you prefer that we open a bug for tracking.

We, Debian, only take patches outside of the stable process in pretty
specific cases.  Less so if this applies to older releases.

In this case, please upgrade to the latest Debian release, 13.

Bastian

-- 
Love sometimes expresses itself in sacrifice.
		-- Kirk, "Metamorphosis", stardate 3220.3

[toc] | [prev] | [standalone]

Back to top | Article view | linux.debian.kernel

csiph-web