From: Nishanth Aravamudan <nacc@linux.vnet.ibm.com>
To: Brice Goglin <Brice.Goglin@inria.fr>
Cc: Boqun Feng <boqun.feng@linux.vnet.ibm.com>,
Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
Peter Zijlstra <peterz@infradead.org>,
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: Thu, 9 Apr 2015 15:37:09 -0700 [thread overview]
Message-ID: <20150409223709.GF53918@linux.vnet.ibm.com> (raw)
In-Reply-To: <552503A1.3050502@inria.fr>
On 08.04.2015 [12:32:01 +0200], Brice Goglin wrote:
> 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?
There is some mention of "User Space Notification" in cpu-hotplug.txt,
but no idea if it's current.
-Nish
WARNING: multiple messages have this Message-ID (diff)
From: Nishanth Aravamudan <nacc@linux.vnet.ibm.com>
To: Brice Goglin <Brice.Goglin@inria.fr>
Cc: Peter Zijlstra <peterz@infradead.org>,
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: Thu, 9 Apr 2015 15:37:09 -0700 [thread overview]
Message-ID: <20150409223709.GF53918@linux.vnet.ibm.com> (raw)
In-Reply-To: <552503A1.3050502@inria.fr>
On 08.04.2015 [12:32:01 +0200], Brice Goglin wrote:
> 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?
There is some mention of "User Space Notification" in cpu-hotplug.txt,
but no idea if it's current.
-Nish
next prev parent reply other threads:[~2015-04-09 22:37 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
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 [this message]
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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