Re: [PATCH 0/1] speeding up cpu_up()

[Aravind Gopalakrishnan]

On 5/3/2015 11:13 AM, Aravind Gopalakrishnan wrote:
> On 5/1/15 7:42 PM, Aravind Gopalakrishnan wrote:
> > On 5/1/15 5:47 PM, Borislav Petkov wrote:
> > > Aravind and I could probably test on a couple of AMD boxes to narrow 
> > > down.
> > >
> > > @Aravind, see here:
> > >
> > > https://lkml.kernel.org/r/87d69aab88c14d65ae1e7be55050d1b689b59b4b.1429402494.git.len.brown@xxxxxxxxx 
> > >
> > >
> > > You could ask around whether a timeout is needed between the assertion
> > > and deassertion of INIT done by the BSP when booting other cores.
> >
> > Sure, I'll ask around and try mdelay(0) on some systems as well.
> > I can gather Fam15h, Fam16h but don't have K8's or older.
> >
> > Will let you know how it goes.
> Update:
> Fam15h Model00h-0fh, Fam15hModel60h and Fam16h Model 00h-0fh 
> processors boot fine with mdelay(0) and BSP brings up all secondary 
> cpus correctly. I don't have Fam15hModel30h system currently up, but 
> I'll try that too tomorrow.
>
> I am yet to get feedback from HW folks regarding this though.

Tested a delay of 0 on Fam10h and Fam15h Model 30h-3fh and both work fine.

Feedback from asking internally about this is that we should be OK to 
move to a no-delay default from K8 onwards.

Thanks,
-Aravind.
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