Re: [PATCH v2 2/4] Add enabling of the R3 MWAIT during boot for KNL

From: Dave Hansen
Date: Wed Oct 12 2016 - 10:45:06 EST


On 10/12/2016 06:35 AM, Thomas Gleixner wrote:
> On Wed, 12 Oct 2016, Grzegorz Andrejczuk wrote:
>> > + /*
>> > + * Setting ring 3 MONITOR/MWAIT for all threads
>> > + * when CPU is Xeon Phi Family x200
>> > + * This can be disabled with phir3mwait=disable cmdline switch.
>> > + * We preserve the reserved values and set only 2nd bit.
>> > + * Ref:
>> > + * https://software.intel.com/en-us/blogs/2016/10/06/intel-xeon-phi-product-family-x200-knl-user-mode-ring-3-monitor-and-mwait
> Please don't put links like this into comments. They are stale before this
> hits Linus tree.

Yeah, I'm worried about this too. It's probably best to include some
version of the text in that blog entry, or that text itself. That way,
when Intel reorganizes and culls old blog entries, we won't completely
lose our source.