From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Gautham R Shenoy <ego@in.ibm.com>,
linux-kernel@vger.kernel.org,
Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>,
Arun R Bharadwaj <arun@linux.vnet.ibm.com>,
linuxppc-dev@lists.ozlabs.org,
"Darrick J. Wong" <djwong@us.ibm.com>
Subject: Re: [PATCH v3 0/3] cpu: pseries: Cpu offline states framework
Date: Thu, 24 Sep 2009 10:51:41 +1000 [thread overview]
Message-ID: <1253753501.7103.358.camel@pasglop> (raw)
In-Reply-To: <1253016701.5506.73.camel@laptop>
On Tue, 2009-09-15 at 14:11 +0200, Peter Zijlstra wrote:
> I still think its a layering violation... its the hypervisor manager
> that should be bothered in what state an off-lined cpu is in.
>
That's not how our hypervisor works.
If you ask through the management interface, to remove a CPU from a
partition, the HV will communicate with a daemon inside the partition
that will then unplug the CPU via the right call.
I don't really understand your objections to be honest. And I fail to
see why it would be a layering violation to have the ability for the OS
to indicate in what state it wishes to relinguish a CPU to the
hypervisor, which more or less defines what is the expected latency for
getting it back later on.
Ben.
WARNING: multiple messages have this Message-ID (diff)
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Gautham R Shenoy <ego@in.ibm.com>,
Joel Schopp <jschopp@austin.ibm.com>,
Balbir Singh <balbir@in.ibm.com>,
Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>,
Dipankar Sarma <dipankar@in.ibm.com>,
Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>,
Arun R Bharadwaj <arun@linux.vnet.ibm.com>,
linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
"Darrick J. Wong" <djwong@us.ibm.com>
Subject: Re: [PATCH v3 0/3] cpu: pseries: Cpu offline states framework
Date: Thu, 24 Sep 2009 10:51:41 +1000 [thread overview]
Message-ID: <1253753501.7103.358.camel@pasglop> (raw)
In-Reply-To: <1253016701.5506.73.camel@laptop>
On Tue, 2009-09-15 at 14:11 +0200, Peter Zijlstra wrote:
> I still think its a layering violation... its the hypervisor manager
> that should be bothered in what state an off-lined cpu is in.
>
That's not how our hypervisor works.
If you ask through the management interface, to remove a CPU from a
partition, the HV will communicate with a daemon inside the partition
that will then unplug the CPU via the right call.
I don't really understand your objections to be honest. And I fail to
see why it would be a layering violation to have the ability for the OS
to indicate in what state it wishes to relinguish a CPU to the
hypervisor, which more or less defines what is the expected latency for
getting it back later on.
Ben.
next prev parent reply other threads:[~2009-09-24 0:54 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-09-15 12:06 [PATCH v3 0/3] cpu: pseries: Cpu offline states framework Gautham R Shenoy
2009-09-15 12:07 ` [PATCH v3 1/3] pSeries: cede latency specifier helper function Gautham R Shenoy
2009-09-15 14:45 ` Daniel Walker
2009-09-15 14:45 ` Daniel Walker
2009-09-15 12:07 ` [PATCH v3 2/3] cpu: Offline state Framework Gautham R Shenoy
2009-09-30 17:31 ` Randy Dunlap
2009-09-30 17:31 ` Randy Dunlap
2009-09-15 12:07 ` [PATCH v3 3/3] cpu: Implement cpu-offline-state callbacks for pSeries Gautham R Shenoy
2009-09-15 12:11 ` [PATCH v3 0/3] cpu: pseries: Cpu offline states framework Peter Zijlstra
2009-09-15 12:11 ` Peter Zijlstra
2009-09-15 13:21 ` Michael Ellerman
2009-09-15 14:58 ` Balbir Singh
2009-09-15 14:58 ` Balbir Singh
2009-09-16 7:48 ` Heiko Carstens
2009-09-16 7:48 ` Heiko Carstens
2009-09-24 0:52 ` Benjamin Herrenschmidt
2009-09-24 0:52 ` Benjamin Herrenschmidt
2009-09-16 15:28 ` Dipankar Sarma
2009-09-16 15:28 ` Dipankar Sarma
2009-09-16 15:32 ` Peter Zijlstra
2009-09-16 15:32 ` Peter Zijlstra
2009-09-16 16:24 ` Dipankar Sarma
2009-09-16 16:24 ` Dipankar Sarma
2009-09-16 16:35 ` Peter Zijlstra
2009-09-16 16:35 ` Peter Zijlstra
2009-09-16 17:03 ` Vaidyanathan Srinivasan
2009-09-16 17:03 ` Vaidyanathan Srinivasan
2009-09-16 17:22 ` Peter Zijlstra
2009-09-16 17:22 ` Peter Zijlstra
2009-09-16 20:17 ` Dipankar Sarma
2009-09-16 20:17 ` Dipankar Sarma
2009-09-24 0:55 ` Benjamin Herrenschmidt
2009-09-24 0:55 ` Benjamin Herrenschmidt
2009-09-24 0:51 ` Benjamin Herrenschmidt [this message]
2009-09-24 0:51 ` Benjamin Herrenschmidt
2009-09-25 14:48 ` Peter Zijlstra
2009-09-25 14:48 ` Peter Zijlstra
2009-09-25 21:12 ` Benjamin Herrenschmidt
2009-09-25 21:12 ` Benjamin Herrenschmidt
2009-09-28 13:53 ` Vaidyanathan Srinivasan
2009-09-28 13:53 ` Vaidyanathan Srinivasan
2009-09-28 13:51 ` Vaidyanathan Srinivasan
2009-09-28 13:51 ` Vaidyanathan Srinivasan
2009-09-26 9:55 ` Pavel Machek
2009-09-26 9:55 ` Pavel Machek
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