On Thu, Dec 12, 2019 at 3:48 AM Peter Robinson <pbrobinson(a)gmail.com> wrote:
Hey All.
In digging through some pieces around CPU_IDLE I noticed that
NO_HZ_IDLE is explicitly disabled on x86_64 but not on all other
architectures.
Doing a "git log --follow
configs/fedora/generic/x86/x86_64/CONFIG_NO_HZ_IDLE" it goes all the
way back to 2016 when we changed the way the configs were handled.
The upstream kernel's opinion [1] on it is "Most of the time you want
to say Y here." so I'm wondering if there's a reason why we're
difference on x86_64 or is it just lost in the winds of time?
Peter
PS was digging around CPU_IDLE_GOV_TEO for those curious.
[1]
https://cateee.net/lkddb/web-lkddb/NO_HZ_IDLE.html
commit 3836faf6e68495fc70316229a3540506f7ce4c98
Author: Kyle McMartin <kyle(a)fedoraproject.org>
Date: Wed Sep 17 13:10:12 2014 -0500
re-enable RCU_FAST_NO_HZ, enable NO_HZ_FULL on x86_64
- I also like to live dangerously. (Re-enable RCU_FAST_NO_HZ which
has been off
since April 2012. Also enable NO_HZ_FULL on x86_64.)