Messages in this thread | | | Date | Sun, 3 May 2015 11:13:25 -0500 | From | Aravind Gopalakrishnan <> | Subject | Re: [PATCH 0/1] speeding up cpu_up() |
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On 5/1/15 7:42 PM, Aravind Gopalakrishnan wrote: > > On 5/1/15 5:47 PM, Borislav Petkov wrote: >> On Fri, May 01, 2015 at 02:42:39PM -0700, Len Brown wrote: >>> On Mon, Apr 20, 2015 at 12:15 AM, Ingo Molnar <mingo@kernel.org> wrote: >>> >>>> So instead of playing games with an ancient delay, I'd suggest we >>>> install the 10 msec INIT assertion wait as a platform quirk instead, >>>> and activate it for all CPUs/systems that we think might need it, with >>>> a sufficiently robust and future-proof quirk cutoff condition. >>>> >>>> New systems won't have the quirk active and thus won't have to have >>>> this delay configurable either. >>> Okay, at this time, I think the quirk would apply to: >>> >>> 1. Intel family 5 (original pentium) -- some may actually need the >>> quirk >>> 2. Intel family F (pentium4) -- mostly b/c I don't want to bother >>> finding/testing p4 >>> 3. All AMD (happy to narrow down, if somebody can speak for AMD) >> 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@intel.com >> >> >> 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.
Thanks, -Aravind.
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