RE: [PATCH] X86/CPU: Avoid 100ms sleep for cpu offline during S3

[Lan, Tianyu]

Have you tried my attached kernel config file? When someone reported
the issue to me, I also was very hard to reproduce the issue by my own config
file. Maybe once 100 tries. But I can reproduced the issue every time with
the attached configure file on several my machines and even on server.

-----Original Message-----
From: Borislav Petkov [mailto:bp@xxxxxxxxx] 
Sent: Wednesday, August 06, 2014 7:08 PM
To: Lan, Tianyu
Cc: tglx@xxxxxxxxxxxxx; mingo@xxxxxxxxxx; hpa@xxxxxxxxx; x86@xxxxxxxxxx; toshi.kani@xxxxxx; imammedo@xxxxxxxxxx; jan.kiszka@xxxxxxxxxxx; mingo@xxxxxxxxxx; huawei.libin@xxxxxxxxxx; prarit@xxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Brandt, Todd E
Subject: Re: [PATCH] X86/CPU: Avoid 100ms sleep for cpu offline during S3

On Tue, Aug 05, 2014 at 05:29:18PM +0800, Lan Tianyu wrote:
> I think you can pull Tod's tool from git hub and do test from your 
> laptop. I attached a configure file come from ubuntu which is easier 
> to produce the issue. You can use it to reproduce the issue.

Right, so I ran it on an old dualcore AMD laptop I have lying around here and it didn't show any difference with or without your patch.

For all 4 runs I did with the tool running it without any arguments (so it did the default thing), I got suspend time for CPU1 of 4-6 msec and resume of ~20msec.

I don't know whether it is the dual core or AMD but your patch doesn't change anything on that laptop which is ok, I'd guess.

> Ok. BTW, I have tested it on the Ivbridge and Haswell machines.

Yeah, add those numbers to the commit message too.

Thanks.

--
Regards/Gruss,
    Boris.

Sent from a fat crate under my desk. Formatting is fine.
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