From: baruch@tkos.co.il (Baruch Siach)
To: linux-arm-kernel@lists.infradead.org
Subject: halting the kernel does not stop the CPU cores?
Date: Thu, 27 Jul 2017 21:27:43 +0300 [thread overview]
Message-ID: <20170727182743.ma4bo54mar4bknap@tarshish> (raw)
In-Reply-To: <VI1PR04MB1662099750F9EAFA0324C6538CBE0@VI1PR04MB1662.eurprd04.prod.outlook.com>
Hi Heinz,
On Thu, Jul 27, 2017 at 02:38:48PM +0000, Heinz Wrobel wrote:
> I noticed that when halting the kernel (intentionally or not), the cores
> effectively go into a while(1) loop and power consumption on larger devices
> really jumps up significantly to the point where, e.g., a ?crash? turns into
> ?crash and burn?.
>
> I would assume that if a system is halted, you don?t want to dissipate more
> power than on a running system but go as silent as low power as reasonable.
>
> Is there any specific reason why the cores would not go into a wfi loop like
> they do on idle?
> The patch to fix this seems to be easy at first glance, but is there a good
> reason *NOT* to do such a patch and to leave the plain while(1)?
See https://patchwork.kernel.org/patch/9866711/ .
baruch
--
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next prev parent reply other threads:[~2017-07-27 18:27 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-27 14:38 halting the kernel does not stop the CPU cores? Heinz Wrobel
2017-07-27 18:27 ` Baruch Siach [this message]
2017-07-27 20:07 ` Florian Fainelli
2017-07-27 22:25 ` Russell King - ARM Linux
2017-07-27 23:27 ` icenowy at aosc.io
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