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From: Thomas Huth <thuth@redhat.com>
To: David Gibson <david@gibson.dropbear.id.au>,
	Bharata B Rao <bharata@linux.vnet.ibm.com>
Cc: agraf@suse.de, aik@ozlabs.ru, qemu-devel@nongnu.org,
	mdroth@linux.vnet.ibm.com, qemu-ppc@nongnu.org,
	tyreld@linux.vnet.ibm.com, imammedo@redhat.com,
	nfont@linux.vnet.ibm.com, afaerber@suse.de
Subject: Re: [Qemu-devel] [RFC PATCH v4 09/11] spapr: Support topologies with unfilled cores
Date: Fri, 4 Sep 2015 10:44:57 +0200	[thread overview]
Message-ID: <55E95A09.8030700@redhat.com> (raw)
In-Reply-To: <20150904070105.GB6537@voom.redhat.com>

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On 04/09/15 09:01, David Gibson wrote:
> On Thu, Aug 06, 2015 at 10:57:15AM +0530, Bharata B Rao wrote:
>> QEMU currently supports CPU topologies where there can be cores
>> which are not completely filled with all the threads as per the
>> specifed SMT mode.
>>
>> Restore support for such topologies (Eg -smp 15,cores=4,threads=4)
>> The last core will always have the deficit even when -device options are
>> used to cold-plug the cores.
>>
>> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
> 
> Is there a reason to support these silly toplogies, or should we just
> error out if this is specified?

FYI, I've recently submitted a patch that tries to catch such illegal
SMP configurations and simply errors out in that case:

http://lists.nongnu.org/archive/html/qemu-devel/2015-07/msg04549.html

It's not upstream yet, but already in Eduardo's x86 branch. I think this
will reject the bad topology from your example, too.

 Thomas



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  reply	other threads:[~2015-09-04  8:45 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-08-06  5:27 [Qemu-devel] [RFC PATCH v4 00/11] sPAPR CPU hotplug Bharata B Rao
2015-08-06  5:27 ` [Qemu-devel] [RFC PATCH v4 01/11] exec: Remove cpu from cpus list during cpu_exec_exit() Bharata B Rao
2015-09-04  5:31   ` David Gibson
2015-09-09  5:52     ` Bharata B Rao
2015-09-09  7:41       ` Zhu Guihua
2015-09-09  7:56         ` Bharata B Rao
2015-11-12  9:11           ` Zhu Guihua
2015-11-12  9:30             ` Bharata B Rao
2015-11-12  9:41               ` Zhu Guihua
2015-11-12  9:56               ` Andreas Färber
2015-11-12 11:40                 ` Bharata B Rao
2015-08-06  5:27 ` [Qemu-devel] [RFC PATCH v4 02/11] exec: Do vmstate unregistration from cpu_exec_exit() Bharata B Rao
2015-09-04  6:03   ` David Gibson
2015-09-09  5:56     ` Bharata B Rao
2015-08-06  5:27 ` [Qemu-devel] [RFC PATCH v4 03/11] cpus: Reclaim vCPU objects Bharata B Rao
2015-09-04  6:09   ` David Gibson
2015-08-06  5:27 ` [Qemu-devel] [RFC PATCH v4 04/11] cpus: Add a sync version of cpu_remove() Bharata B Rao
2015-09-04  6:11   ` David Gibson
2015-09-09  5:57     ` Bharata B Rao
2015-08-06  5:27 ` [Qemu-devel] [RFC PATCH v4 05/11] xics_kvm: Add cpu_destroy method to XICS Bharata B Rao
2015-08-07 11:33   ` Bharata B Rao
2015-08-06  5:27 ` [Qemu-devel] [RFC PATCH v4 06/11] spapr: Create pseries-2.5 machine Bharata B Rao
2015-08-06  5:27 ` [Qemu-devel] [RFC PATCH v4 07/11] spapr: Enable CPU hotplug for pseries-2.5 and add CPU DRC DT entries Bharata B Rao
2015-09-04  6:28   ` David Gibson
2015-08-06  5:27 ` [Qemu-devel] [RFC PATCH v4 08/11] spapr: CPU hotplug support Bharata B Rao
2015-09-04  6:58   ` David Gibson
2015-09-09  6:52     ` Bharata B Rao
2015-08-06  5:27 ` [Qemu-devel] [RFC PATCH v4 09/11] spapr: Support topologies with unfilled cores Bharata B Rao
2015-09-04  7:01   ` David Gibson
2015-09-04  8:44     ` Thomas Huth [this message]
2015-09-09  6:58       ` Bharata B Rao
2015-08-06  5:27 ` [Qemu-devel] [RFC PATCH v4 10/11] spapr: CPU hot unplug support Bharata B Rao
2015-08-06  5:27 ` [Qemu-devel] [RFC PATCH v4 11/11] target-ppc: Enable CPU hotplug for POWER8 CPU family Bharata B Rao
2015-08-06  8:42 ` [Qemu-devel] [RFC PATCH v4 00/11] sPAPR CPU hotplug Zhu Guihua
2015-08-10  3:31   ` Bharata B Rao
2015-08-12  2:56 ` David Gibson

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