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Re: [Xen-devel] [Patch] Call sched_destroy_domain before cpupool_rm_domain.

  • To: Jan Beulich <JBeulich@xxxxxxxx>
  • From: Juergen Gross <juergen.gross@xxxxxxxxxxxxxx>
  • Date: Thu, 07 Nov 2013 10:43:42 +0100
  • Cc: George Dunlap <george.dunlap@xxxxxxxxxxxxx>, Dario Faggioli <dario.faggioli@xxxxxxxxxx>, Keir Fraser <keir@xxxxxxx>, Nate Studer <nate.studer@xxxxxxxxxxxxxxx>, xen-devel@xxxxxxxxxxxxx
  • Delivery-date: Thu, 07 Nov 2013 10:40:45 +0000
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On 07.11.2013 10:37, Jan Beulich wrote:
On 07.11.13 at 10:09, Juergen Gross <juergen.gross@xxxxxxxxxxxxxx> wrote:
On 07.11.2013 08:39, Jan Beulich wrote:
On 05.11.13 at 06:59, Juergen Gross <juergen.gross@xxxxxxxxxxxxxx> wrote:
On 04.11.2013 16:22, Nate Studer wrote:
On 11/4/2013 4:58 AM, Juergen Gross wrote:
All other schedulers will just call xfree() for the domain specific data
may be update some statistic data, which is not critical).

The credit and credit2 schedulers do a bit more than that in their

Sorry, got not enough sleep on the weekend ;-)

I checked only 4.1 and 4.2 trees. There only xfree of the domain data is

The credit scheduler frees the node_affinity_cpumask contained in the domain
data and the credit2 scheduler deletes a list element contained in the
data.  Since with this bug they are accessing structures that do not belong
them, bad things happen.

So the patch would be subject to a 4.3 backport, I think.

Hmm, I'm slightly confused: credit2's free_domdata has always been
doing more than just xfree() afaict, and hence backporting is either
necessary uniformly or (taking into account that it was made clear
that arinc doesn't work with CPU pools anyway so far) not at all.

Please clarify.

Okay, I assumed only "production ready" features are to be taken into
for a backport. And credit2 is clearly not in this state, or am I wrong?

You aren't, but is arinc production ready? I wouldn't think so
simply based on it not working with CPU pools. And then the
backporting question would become mute.

No, it doesn't. The following statement should have made that clear:

A 4.3 backport should be considered in any case, as sedf and credit
behave differently in free_domdata, and both are "production ready".

If you have credit as default scheduler and use sedf in a cpupool, destroying
a domain in the cpupool with sedf will use the credit free_domdata routine,
leading to an error in 4.3 when calling free_cpumask_var().


Juergen Gross                 Principal Developer Operating Systems
PBG PDG ES&S SWE OS6                   Telephone: +49 (0) 89 62060 2932
Fujitsu                                   e-mail: juergen.gross@xxxxxxxxxxxxxx
Mies-van-der-Rohe-Str. 8                Internet: ts.fujitsu.com
D-80807 Muenchen                 Company details: ts.fujitsu.com/imprint.html

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