From: Tejun Heo <tj@kernel.org>
To: Christoph Lameter <cl@linux-foundation.org>
Cc: Andi Kleen <andi@firstfloor.org>, Ingo Molnar <mingo@elte.hu>,
Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org, x86@kernel.org,
linux-arch@vger.kernel.org, hpa@zytor.com, tglx@linutronix.de
Subject: Re: [PATCHSET] percpu: generalize first chunk allocators and improve lpage NUMA support
Date: Thu, 02 Jul 2009 07:42:18 +0900 [thread overview]
Message-ID: <4A4BE64A.3050805@kernel.org> (raw)
In-Reply-To: <alpine.DEB.1.10.0907011330450.9522@gentwo.org>
Christoph Lameter wrote:
> On Wed, 1 Jul 2009, Andi Kleen wrote:
>
>> And it's imho unclear if that is all worth it just to avoid
>> wasting some memory in the "256 possible CPUs" case (which
>> I doubt is particularly realistic anyways, at least I don't
>> know of any Hypervisor today that scales to 256 CPUs)
>
> I basically agree. Its not worth it given the rare cases where this
> matters. It will be a lot of code with callbacks in each subsystem.
>
> One of the motivations of working on revising the percpu handling for
> me was that we could get rid of these screwy callbacks that are rarely
> tested and cause all sorts of other issues with locking and serialization.
Hmmm.... yeah. I have to agree that callbacks are nasty and requiring
all users to use callbacks wouldn't be very nice. Once the current
dust settles down, I'll look around and see whether this can be solved
in some reasonable way.
Thanks.
--
tejun
next prev parent reply other threads:[~2009-07-01 22:43 UTC|newest]
Thread overview: 66+ 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
2009-06-24 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
2009-06-30 22:40 ` Andi Kleen
2009-07-01 0:48 ` Tejun Heo
2009-06-30 22:55 ` Christoph Lameter
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 [this message]
2009-07-03 23:14 ` Tejun Heo
2009-07-03 23:14 ` Tejun Heo
2009-07-13 10:12 ` [PATCH 04/10] percpu: make 4k first chunk allocator map memory David Howells
2009-07-15 3:17 ` Tejun Heo
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