linux-kernel - Re: [RFC V2 PATCH 4/6] cpuidle/ppc: Add longnap state to the idle states on powernv

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <5215D540.9020309@linux.vnet.ibm.com>
Date:	Thu, 22 Aug 2013 14:39:20 +0530
From:	Preeti U Murthy <preeti@...ux.vnet.ibm.com>
To:	Benjamin Herrenschmidt <benh@...nel.crashing.org>
CC:	fweisbec@...il.com, paul.gortmaker@...driver.com, paulus@...ba.org,
	shangw@...ux.vnet.ibm.com, galak@...nel.crashing.org,
	deepthi@...ux.vnet.ibm.com, paulmck@...ux.vnet.ibm.com,
	arnd@...db.de, linux-pm@...r.kernel.org, rostedt@...dmis.org,
	rjw@...k.pl, john.stultz@...aro.org, tglx@...utronix.de,
	chenhui.zhao@...escale.com, michael@...erman.id.au,
	r58472@...escale.com, geoff@...radead.org,
	linux-kernel@...r.kernel.org, srivatsa.bhat@...ux.vnet.ibm.com,
	schwidefsky@...ibm.com, svaidy@...ux.vnet.ibm.com,
	linuxppc-dev@...ts.ozlabs.org
Subject: Re: [RFC V2 PATCH 4/6] cpuidle/ppc: Add longnap state to the idle
 states on powernv

Hi Ben,

On 08/22/2013 08:58 AM, Benjamin Herrenschmidt wrote:
> On Wed, 2013-08-14 at 17:26 +0530, Preeti U Murthy wrote:
>> This patch hooks into the existing broadcast framework along with the support
>> that this patchset introduces for ppc, and the cpuidle driver backend
>> for powernv(posted out by Deepthi Dharwar:https://lkml.org/lkml/2013/7/23/128)
>> to add sleep state as one of the deep idle states, in which the decrementer
>> is switched off.
>>
>> However in this patch, we only emulate sleep by going into a state which does
>> a nap with the decrementer interrupts disabled, termed as longnap. This enables
>> focus on the timer broadcast framework for ppc in this series of patches ,
>> which is required as a first step to enable sleep on ppc.
> 
> This is only for debug / proof of concept right ? We should use a real
> sleep here.
> 
> If we need to know whether the FW supports it (PORE etc...) we shall add
> a device-tree property from the FW to indicate that fact.

We also need the sleep support right? The context management, I mean.
Yes it is a debug patch, so as to first ensure that we have the hook up
to the broadcast framework done right.

Regards
Preeti U Murthy

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/