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From: Brice Goglin <Brice.Goglin@inria.fr>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Boqun Feng <boqun.feng@linux.vnet.ibm.com>,
	Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
	Nishanth Aravamudan <nacc@linux.vnet.ibm.com>,
	linux-kernel@vger.kernel.org, Ingo Molnar <mingo@redhat.com>,
	Anton Blanchard <anton@samba.org>,
	linuxppc-dev@lists.ozlabs.org,
	Anshuman Khandual <khandual@linux.vnet.ibm.com>
Subject: Re: Topology updates and NUMA-level sched domains
Date: Wed, 08 Apr 2015 12:32:01 +0200	[thread overview]
Message-ID: <552503A1.3050502@inria.fr> (raw)
In-Reply-To: <20150407194129.GT23123@twins.programming.kicks-ass.net>

Le 07/04/2015 21:41, Peter Zijlstra a écrit :
> No, that's very much not the same. Even if it were dealing with hotplug
> it would still assume the cpu to return to the same node.
>
> But mostly people do not even bother to handle hotplug.
>

You said userspace assumes the cpu<->node relation is a boot-time fixed
one, and hotplug breaks this. How do you expect userspace to handle
hotplug? Is there a convenient way to be notified when a CPU (or memory)
is unplugged?

thanks
Brice

WARNING: multiple messages have this Message-ID (diff)
From: Brice Goglin <Brice.Goglin@inria.fr>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Nishanth Aravamudan <nacc@linux.vnet.ibm.com>,
	Ingo Molnar <mingo@redhat.com>,
	linux-kernel@vger.kernel.org,
	Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
	Boqun Feng <boqun.feng@linux.vnet.ibm.com>,
	Anshuman Khandual <khandual@linux.vnet.ibm.com>,
	linuxppc-dev@lists.ozlabs.org,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Anton Blanchard <anton@samba.org>
Subject: Re: Topology updates and NUMA-level sched domains
Date: Wed, 08 Apr 2015 12:32:01 +0200	[thread overview]
Message-ID: <552503A1.3050502@inria.fr> (raw)
In-Reply-To: <20150407194129.GT23123@twins.programming.kicks-ass.net>

Le 07/04/2015 21:41, Peter Zijlstra a écrit :
> No, that's very much not the same. Even if it were dealing with hotplug
> it would still assume the cpu to return to the same node.
>
> But mostly people do not even bother to handle hotplug.
>

You said userspace assumes the cpu<->node relation is a boot-time fixed
one, and hotplug breaks this. How do you expect userspace to handle
hotplug? Is there a convenient way to be notified when a CPU (or memory)
is unplugged?

thanks
Brice

  reply	other threads:[~2015-04-08 10:42 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-04-06 21:45 Topology updates and NUMA-level sched domains Nishanth Aravamudan
2015-04-06 21:45 ` Nishanth Aravamudan
2015-04-07 10:21 ` Peter Zijlstra
2015-04-07 10:21   ` Peter Zijlstra
2015-04-07 17:14   ` Nishanth Aravamudan
2015-04-07 17:14     ` Nishanth Aravamudan
2015-04-07 19:41     ` Peter Zijlstra
2015-04-07 19:41       ` Peter Zijlstra
2015-04-08 10:32       ` Brice Goglin [this message]
2015-04-08 10:32         ` Brice Goglin
2015-04-08 10:52         ` Peter Zijlstra
2015-04-08 10:52           ` Peter Zijlstra
2015-04-09 22:40           ` Nishanth Aravamudan
2015-04-09 22:40             ` Nishanth Aravamudan
2015-04-09 22:37         ` Nishanth Aravamudan
2015-04-09 22:37           ` Nishanth Aravamudan
2015-04-09 22:29       ` Nishanth Aravamudan
2015-04-09 22:29         ` Nishanth Aravamudan
2015-04-10  8:31         ` Peter Zijlstra
2015-04-10  8:31           ` Peter Zijlstra
2015-04-10  9:08           ` Peter Zijlstra
2015-04-10  9:08             ` Peter Zijlstra
2015-04-10 19:50             ` Nishanth Aravamudan
2015-04-10 19:50               ` Nishanth Aravamudan
2015-04-10 20:30           ` Nishanth Aravamudan
2015-04-10 20:30             ` Nishanth Aravamudan

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