]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
tile: nohz: warn if nohz_full uses hypervisor shared cores
authorChris Metcalf <cmetcalf@ezchip.com>
Mon, 30 Mar 2015 20:33:00 +0000 (16:33 -0400)
committerChris Metcalf <cmetcalf@ezchip.com>
Fri, 17 Apr 2015 18:01:41 +0000 (14:01 -0400)
commit128f3cb9398b5eeb4ee04b60bd5e314f5c122821
treea9cb1e04a11883d1ad9587779155cdd82d67958f
parent437d3e124d25daaa671bfecfd4015ecd2503a955
tile: nohz: warn if nohz_full uses hypervisor shared cores

The "hypervisor shared" cores are ones that the Tilera hypervisor
uses to receive interrupts to manage hypervisor-owned devices.
It's a bad idea to try to use those cores with nohz_full, since
they will get interrupted unpredictably -- and invisibly to Linux
tracing tools, since the interrupts are delivered at a higher
privilege level to the Tilera hypervisor.

Generate a clear warning at boot up that this doesn't end well
for the nohz_full cores in question.

Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
arch/tile/include/hv/hypervisor.h
arch/tile/kernel/setup.c