Messages in this thread | | | From | "Brown, Len" <> | Subject | RE: [PATCH 1/1] x86: replace cpu_up hard-coded mdelay with variable | Date | Mon, 20 Apr 2015 12:37:52 +0000 |
| |
> What's the cutoff for 'modern hardware' - which CPUs stopped requiring > the delay?
This is the topic of ongoing research, and I'm not ready to send the patch setting a new default until I've heard back from a few more HW people.
Every system I've tested appears to work with delay 0. Were I to guess, I'd venture that every system that runs an X86_64 kernel might count as "modern" -- even the 2005 AMD Turion laptop I've got in the bone pile.
> Also, is there any public document where the no-delay is specified for > 'modern hardware'?
Unfortunately only the converse is true. There is an ancient document specifying that the delay may be necessary.
cheers, -Len
| |