(bisected) Lock up on sh73a0/kzm9g on cpuidle initialization
geert at linux-m68k.org
Thu Nov 6 12:38:26 PST 2014
When CONFIG_CPU_IDLE=y, the kernel locks up during cpuidle initialization
on Renesas sh73a0/kzm9g-reference, which has a dual-core Cortex-A9.
Last message is:
DMA: preallocated 256 KiB pool for atomic coherent allocations
After this it's supposed to print:
cpuidle: using governor ladder
cpuidle: using governor menu
I've bisected this to commit 442bf3aaf55a91ebfec71da46a4ee10a3c905bcc
("sched: Let the scheduler see CPU idle states").
Reverting that commit, and commit 83a0a96a5f26d974580fd7251043ff70c8f1823d
("sched/fair: Leverage the idle state info when choosing the "idlest"
depends on it, fixes the problem.
I saw the discussion "lockdep splat in CPU hotplug", so I enabled lockdep
debugging, but didn't see a lockdep splat.
I'm using CONFIG_TREE_RCU=y, as this is SMP without PREEMPT.
Anyone with a clue?
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
More information about the linux-arm-kernel