DescriptionGeoff Gustafson
2008-05-12 22:56:27 UTC
1. Feature Name: enable deep C states for Nehalem
Because RH is getting some late pressure from OEMs and customers for
TylersburgEP/Nehalem support in 4.7, I'm concerned that this might be required.
We had intended only to submit it for 5.3, but I now plan to look at it ASAP in
the 4.7 context.
This patch that went upstream in June 2007 gives a a 16x improvement in
efficiency at idle on Nehalem chips.
http://git.kernel.org/gitweb.cgi?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=18eab8550397f1f3d4b8b2c5257c88dae25d58ed
2. Description:
Architectures (mark all that apply)
x 32-bit x86
64-bit Itanium2
x 64-bit Intel EM64T
Dependencies:
External links:
Priority (H,M,L): H
Target Releases:
Target Release Date:
Drivers or hardware dependency:
Target Kernel:
3. Business Justification:
a. Why is this feature needed?
Big power efficiency improvement
b. What hardware does this enable?
Nehalem CPUs
c. Forecast, volume or high end platform?
Volume
d. Any configuration info?
e. When needed?
f. Are there other dependencies (drivers).
4. Status:
a. Is code accepted upstream? If so, what version or patch?
See above.
5. Hardware to Red Hat? Red Hat can't integrate/test features without hardware.
Yes, two alpha Tylersburg EP and one Tylersburg HEDT are already at RH, more coming.
6. Partner management contact, email, phone, chat
keve.a.gabbert
7. Partner technical contact, email, phone, chat
jvillalo, grgustaf
The Nehalem processor is integral to the Tylersburg-EP platform that all of the
OEMs will be planning. Moreover, the deep c-states improves the overall power
efficiency of idle CPUs, which many customers are very interested in.