From: Ingo Molnar <mingo@elte.hu>
To: Christoph Lameter <cl@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
tj@kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org,
linux-arch@vger.kernel.org, andi@firstfloor.org, hpa@zytor.com,
tglx@linutronix.de
Subject: Re: [PATCHSET] percpu: generalize first chunk allocators and improve lpage NUMA support
Date: Wed, 1 Jul 2009 00:31:38 +0200 [thread overview]
Message-ID: <20090630223138.GH1241@elte.hu> (raw)
In-Reply-To: <alpine.DEB.1.10.0906301809330.11362@gentwo.org>
* Christoph Lameter <cl@linux-foundation.org> wrote:
> On Tue, 30 Jun 2009, Ingo Molnar wrote:
>
> > But what if not? What if the kernel can run on up to 4096 CPUs
> > and runs on a big box. Why should a virtual machine have the
> > illogical choice between either wasting a lot of RAM
> > preallocating stuff, or limiting its own extendability.
>
> The kernel may be able to run on 4096 but the machines config
> information that is available via ACPI knows how many processors
> the machine we are booting on is able to add.
I think we might be talking past each other.
The usecase i'm talking about is to boot a generic,
many-CPUs-capable kernel in a guest image.
How would you allow that guest to stay on 2 virtual CPUs but still
be able to hot-plug many other CPUs if the guest context rises above
its original CPU utilization?
Ingo
next prev parent reply other threads:[~2009-06-30 22:31 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-06-24 13:30 [PATCHSET] percpu: generalize first chunk allocators and improve lpage NUMA support Tejun Heo
2009-06-24 13:30 ` Tejun Heo
2009-06-24 13:30 ` [PATCH 01/10] x86: make pcpu_chunk_addr_search() matching stricter Tejun Heo
2009-06-24 13:30 ` Tejun Heo
2009-06-24 13:30 ` [PATCH 02/10] percpu: drop @unit_size from embed first chunk allocator Tejun Heo
2009-06-24 13:30 ` Tejun Heo
2009-06-24 13:30 ` [PATCH 03/10] x86,percpu: generalize 4k " Tejun Heo
2009-06-24 13:30 ` Tejun Heo
2009-06-24 13:30 ` [PATCH 04/10] percpu: make 4k first chunk allocator map memory Tejun Heo
2009-06-24 13:30 ` Tejun Heo
2009-07-13 10:12 ` David Howells
2009-07-15 3:17 ` Tejun Heo
2009-06-24 13:30 ` [PATCH 05/10] x86,percpu: generalize lpage first chunk allocator Tejun Heo
2009-06-24 13:30 ` Tejun Heo
2009-06-24 13:30 ` [PATCH 06/10] percpu: simplify pcpu_setup_first_chunk() Tejun Heo
2009-06-24 13:30 ` Tejun Heo
2009-06-24 13:30 ` [PATCH 07/10] percpu: reorder a few functions in mm/percpu.c Tejun Heo
2009-06-24 13:30 ` Tejun Heo
2009-06-24 13:30 ` [PATCH 08/10] percpu: drop pcpu_chunk->page[] Tejun Heo
2009-06-24 13:30 ` Tejun Heo
2009-06-24 13:30 ` [PATCH 09/10] percpu: allow non-linear / sparse cpu -> unit mapping Tejun Heo
2009-06-24 13:30 ` Tejun Heo
2009-06-24 13:30 ` [PATCH 10/10] percpu: teach large page allocator about NUMA Tejun Heo
2009-06-24 13:30 ` Tejun Heo
2009-06-24 23:55 ` [PATCHSET] percpu: generalize first chunk allocators and improve lpage NUMA support Andrew Morton
2009-06-25 0:02 ` Andi Kleen
2009-06-25 0:13 ` H. Peter Anvin
2009-06-25 9:19 ` Andi Kleen
2009-06-25 14:18 ` H. Peter Anvin
2009-06-25 19:54 ` Andi Kleen
2009-06-25 20:15 ` H. Peter Anvin
2009-06-25 20:26 ` Andi Kleen
2009-06-26 0:40 ` Tejun Heo
2009-06-26 2:02 ` H. Peter Anvin
2009-06-26 6:54 ` Andi Kleen
2009-06-25 2:35 ` Tejun Heo
2009-06-25 9:20 ` Ingo Molnar
2009-06-29 23:20 ` Christoph Lameter
2009-06-29 23:39 ` Andrew Morton
2009-06-30 14:24 ` Christoph Lameter
2009-06-30 19:15 ` Ingo Molnar
2009-06-30 19:39 ` Christoph Lameter
2009-06-30 20:21 ` Scott Lurndal
2009-06-30 21:31 ` Ingo Molnar
2009-06-30 22:16 ` Christoph Lameter
2009-06-30 22:31 ` Ingo Molnar [this message]
2009-06-30 22:40 ` Andi Kleen
2009-07-01 0:48 ` Tejun Heo
2009-06-30 22:55 ` Christoph Lameter
2009-06-30 23:07 ` Ingo Molnar
2009-06-30 23:18 ` Christoph Lameter
2009-06-30 23:30 ` Ingo Molnar
2009-07-01 6:34 ` Andi Kleen
2009-06-30 23:20 ` Tejun Heo
2009-06-30 23:31 ` Ingo Molnar
2009-06-30 23:34 ` H. Peter Anvin
2009-07-01 6:42 ` Andi Kleen
2009-07-01 10:21 ` Tejun Heo
2009-07-01 12:23 ` Andi Kleen
2009-07-01 12:53 ` Tejun Heo
2009-07-01 13:11 ` Andi Kleen
2009-07-01 17:33 ` Christoph Lameter
2009-07-01 22:42 ` Tejun Heo
2009-07-03 23:14 ` Tejun Heo
2009-07-03 23:14 ` Tejun Heo
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