From: Arjan van de Ven <arjan@linux.intel.com>
To: dipankar@in.ibm.com
Cc: Len Brown <lenb@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>,
Trinabh Gupta <trinabh@linux.vnet.ibm.com>,
Stephen Rothwell <sfr@canb.auug.org.au>,
suresh.b.siddha@intel.com, benh@kernel.crashing.org,
venki@google.com, ak@linux.intel.com,
linux-kernel@vger.kernel.org, xen-devel@lists.xensource.com
Subject: Re: cpuidle asymmetry (was Re: [RFC PATCH V4 5/5] cpuidle: cpuidle driver for apm)
Date: Fri, 01 Apr 2011 07:38:23 -0700 [thread overview]
Message-ID: <4D95E35F.2080707@linux.intel.com> (raw)
In-Reply-To: <20110401081522.GA22339@in.ibm.com>
On 4/1/2011 1:15 AM, Dipankar Sarma wrote:
> On Fri, Apr 01, 2011 at 12:09:25AM -0400, Len Brown wrote:
>>>> Moorestown is already an example of an asymmetric system,
>>>> since its deepest c-state is available on cpu0, but not on cpu1.
>>>> So it needs different tables for each cpu.
>>> wtf are these hardware guys smoking and how the heck are we supposed to
>>> schedule on such a machine? Prefer to keep cpu1 busy while idling cpu0?
>> they are smoking micro-amps:-)
>>
>> S0i3 on cpu0 can be entered only after cpu1 is already off-line,
>> among other system hardware dependencies...
>>
>> So it makes no sense to export S0i3 as a c-state on cpu1.
>>
>> When cpu1 is online, the scheduler treats it as a normal SMP.
> Isn't S0i3 a "system" state, as opposed to cpu state ?
it's misnamed. it's a C state to the OS.
next prev parent reply other threads:[~2011-04-01 14:38 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20110322123208.28725.30945.stgit@tringupt.in.ibm.com>
[not found] ` <20110322123324.28725.3131.stgit@tringupt.in.ibm.com>
2011-03-22 14:50 ` [RFC PATCH V4 4/5] cpuidle: driver for xen Konrad Rzeszutek Wilk
2011-03-23 9:57 ` Trinabh Gupta
2011-03-24 7:18 ` Len Brown
2011-03-24 12:05 ` Konrad Rzeszutek Wilk
2011-03-25 7:19 ` Len Brown
2011-03-25 14:43 ` Jeremy Fitzhardinge
2011-03-25 14:38 ` [Xen-devel] " Jeremy Fitzhardinge
2011-03-31 2:02 ` Len Brown
2011-03-31 21:26 ` Len Brown
2011-03-31 22:36 ` [Xen-devel] " Jeremy Fitzhardinge
2011-04-01 3:03 ` Len Brown
[not found] ` <20110322123233.28725.92874.stgit@tringupt.in.ibm.com>
[not found] ` <alpine.LFD.2.02.1103222254420.10549@x980>
2011-03-23 9:22 ` [RFC PATCH V4 2/5] cpuidle: list based cpuidle driver registration and selection Trinabh Gupta
2011-03-23 20:51 ` Len Brown
2011-03-24 4:41 ` Len Brown
2011-03-24 14:13 ` Trinabh Gupta
2011-03-24 16:52 ` Vaidyanathan Srinivasan
2011-03-25 7:13 ` Len Brown
2011-03-25 7:05 ` Len Brown
2011-03-25 15:35 ` [Xen-devel] " Konrad Rzeszutek Wilk
2011-03-31 2:25 ` Len Brown
[not found] ` <20110322123244.28725.32435.stgit@tringupt.in.ibm.com>
[not found] ` <alpine.LFD.2.02.1103222304300.10549@x980>
2011-03-23 9:31 ` [RFC PATCH V4 3/5] cpuidle: default idle driver for x86 Trinabh Gupta
2011-03-24 16:32 ` Vaidyanathan Srinivasan
[not found] ` <20110322123223.28725.21929.stgit@tringupt.in.ibm.com>
[not found] ` <20110323120044.bb8c0ae1.sfr@canb.auug.org.au>
2011-03-23 10:10 ` [RFC PATCH V4 1/5] cpuidle: Remove pm_idle pointer " Trinabh Gupta
[not found] ` <20110322123336.28725.29810.stgit@tringupt.in.ibm.com>
[not found] ` <20110323121458.ec7cdaf9.sfr@canb.auug.org.au>
2011-03-23 10:25 ` [RFC PATCH V4 5/5] cpuidle: cpuidle driver for apm Trinabh Gupta
2011-03-23 20:32 ` Len Brown
2011-03-24 14:28 ` Trinabh Gupta
2011-03-24 16:21 ` Vaidyanathan Srinivasan
2011-03-25 7:24 ` Len Brown
2011-03-25 18:01 ` Vaidyanathan Srinivasan
2011-03-31 2:17 ` cpuidle asymmetry (was Re: [RFC PATCH V4 5/5] cpuidle: cpuidle driver for apm) Len Brown
2011-03-31 13:18 ` Peter Zijlstra
2011-04-01 4:09 ` Len Brown
2011-04-01 8:15 ` Dipankar Sarma
2011-04-01 14:38 ` Arjan van de Ven [this message]
2011-04-03 16:18 ` Dipankar Sarma
2011-04-01 14:02 ` Peter Zijlstra
2011-04-04 14:32 ` Dipankar Sarma
2011-04-05 15:01 ` Peter Zijlstra
2011-04-05 15:48 ` Dipankar Sarma
2011-04-01 7:02 ` Trinabh Gupta
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