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From: Christian Borntraeger <borntraeger@de.ibm.com>
To: Thomas Huth <thuth@redhat.com>,
	kvm-ppc@vger.kernel.org, qemu-ppc@nongnu.org,
	kvm@vger.kernel.org
Cc: Alex Williamson <alex.williamson@redhat.com>,
	David Gibson <dgibson@redhat.com>,
	Bharata B Rao <bharata@linux.vnet.ibm.com>
Subject: Re: KVM memory slots limit on powerpc
Date: Fri, 04 Sep 2015 11:59:35 +0200	[thread overview]
Message-ID: <55E96B87.8020900@de.ibm.com> (raw)
In-Reply-To: <55E965FC.8080909@redhat.com>

Am 04.09.2015 um 11:35 schrieb Thomas Huth:
> 
>  Hi all,
> 
> now that we get memory hotplugging for the spapr machine on qemu-ppc,
> too, it seems like we easily can hit the amount of KVM-internal memory
> slots now ("#define KVM_USER_MEM_SLOTS 32" in
> arch/powerpc/include/asm/kvm_host.h). For example, start
> qemu-system-ppc64 with a couple of "-device secondary-vga" and "-m
> 4G,slots=32,maxmem=40G" and then try to hot-plug all 32 DIMMs ... and
> you'll see that it aborts way earlier already.
> 
> The x86 code already increased the amount of KVM_USER_MEM_SLOTS to 509
> already (+3 internal slots = 512) ... maybe we should now increase the
> amount of slots on powerpc, too? Since we don't use internal slots on
> POWER, would 512 be a good value? Or would less be sufficient, too?

When you are at it, the s390 value should also be increased I guess.

Christian


  reply	other threads:[~2015-09-04  9:59 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-09-04  9:35 KVM memory slots limit on powerpc Thomas Huth
2015-09-04  9:59 ` Christian Borntraeger [this message]
2015-09-04 10:04   ` [Qemu-ppc] " Alexander Graf
2015-09-04 10:07     ` Christian Borntraeger
2015-09-04 10:28       ` Thomas Huth
2015-09-04 10:40         ` Benjamin Herrenschmidt
2015-09-04 14:22         ` Alex Williamson
2015-09-04 14:45     ` Thomas Huth
2015-09-07 14:31     ` Igor Mammedov
2015-09-08  6:05       ` Thomas Huth
2015-09-08  7:11         ` Christian Borntraeger
2015-09-08  9:22           ` Thomas Huth

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