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Re: [Xen-users] cpupool-numa-split broken with pinned cpus?

On 13/06/16 22:43, Juergen Gross wrote:
On 13/06/16 10:43, Wei Liu wrote:
CC Dario and Juergen

On Thu, Jun 02, 2016 at 04:01:23PM +1200, Glenn Enright wrote:
Seeing this output, previously (around xen 4.4) it used to work despite the
pinned cpus.

# xl cpupool-numa-split
libxl: error: libxl.c:5516:libxl_set_vcpuonline: Requested 12 VCPUs, however
maxcpus is 2!: Success
error on removing vcpus for Domain-0

And then nothing has changed.

# xl cpupool-list
Name               CPUs   Sched     Active   Domain count
Pool-node0          24    credit       y          7

# xl cpupool-list
Name               CPUs   Sched     Active   Domain count
Pool-node0          24    credit       y          7

# xl vcpu-list 0
Name                                ID  VCPU   CPU State   Time(s) Affinity
(Hard / Soft)
Domain-0                             0     0    0   r--      65.2  0 / all
Domain-0                             0     1    1   -b-      67.8  1 / all

Two issues. One is that the message says success, when no such thing

Uuh, this seems to be a can of worms. The specific issue here is simple
to fix by using LOG() instead of LOGE() in libxl_set_vcpuonline().

There are many more users of LOGE() which I suspect to be wrong,
especially those checking for an error in aodev->rc.

I'd like to address all those cases in a separate series.

I'm also thinking this may be wrong behaviour, since the number of pinned
cores is lower the the number of cores on the first node. It may be that the
test in xl.c around line 5515 should allow this case?

In case there are less online vcpus than the first node has cpus
libxl_set_vcpuonline() shouldn't be called at all. Patch is coming

Are you okay with me adding you as the reporter of this problem in the


Thanks Juergen,

Fine with documenting as reporter, thanks. Good to know there is a clear issue and you have a handle on it.

Regards, Glenn
http://ri.mu - Startups start here. Hosting, Email, DNS, Offsite Backups, Monitoring.

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