From: Peter Zijlstra <peterz@infradead.org>
To: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Martin Schwidefsky <schwidefsky@de.ibm.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] s390/topology: add drawer scheduling domain level
Date: Mon, 13 Jun 2016 13:06:21 +0200 [thread overview]
Message-ID: <20160613110621.GV30909@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <1465376956-100711-3-git-send-email-heiko.carstens@de.ibm.com>
On Wed, Jun 08, 2016 at 11:09:16AM +0200, Heiko Carstens wrote:
> The z13 machine added a fourth level to the cpu topology
> information. The new top level is called drawer.
>
> A drawer contains two books, which used to be the top level.
>
> Adding this additional scheduling domain did show performance
> improvements for some workloads of up to 8%, while there don't
> seem to be any workloads impacted in a negative way.
Right; so no objection.
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
You still don't want to make NUMA explicit on this thing? So while I
suppose the SC 480M L4 cache does hide some of it, there can be up to 8
nodes on this thing. Which seems to me there's win to be had by exposing
it.
Of course, the moment you go all virt/LPAR on it, that all gets really
interesting, but for those cases where you run 1:1 it might make sense.
Also, are you sure you don't want some of the behaviour changed for the
drawer domains? I could for example imagine you wouldn't want
SD_WAKE_AFFINE set (we disable that for NUMA domains as well).
next prev parent reply other threads:[~2016-06-13 11:06 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-08 9:09 [PATCH 0/2] s390: introduce drawer scheduling domain Heiko Carstens
2016-06-08 9:09 ` [PATCH 1/2] topology/sysfs: provide drawer id and siblings attributes Heiko Carstens
2016-06-08 9:09 ` [PATCH 2/2] s390/topology: add drawer scheduling domain level Heiko Carstens
2016-06-13 11:06 ` Peter Zijlstra [this message]
2016-06-13 11:22 ` Heiko Carstens
2016-06-13 13:06 ` Peter Zijlstra
2016-06-13 13:19 ` Martin Schwidefsky
2016-06-13 13:53 ` Peter Zijlstra
2016-06-13 14:37 ` Martin Schwidefsky
2016-06-13 11:25 ` Heiko Carstens
2016-06-13 11:33 ` Peter Zijlstra
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