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SubjectRe: [PATCH] x86/irq: Cure live lock in irq_force_complete_move()
On Fri, 11 Mar 2016, Luck, Tony wrote:
> With this patch applied my system survives me doing
> several rounds of:
>
> # echo 0 | tee /sys/devices/system/cpu/cpu*/online
> # echo 1 | tee /sys/devices/system/cpu/cpu*/online
>
> whereas without the patch the first of those went to
>
> [152455.129604] NMI watchdog: Watchdog detected hard LOCKUP on cpu 96
> [152455.136943] Kernel panic - not syncing: Hard LOCKUP
>
> I'm not sure we care to optimize the cpu offline path, but I'll note here
> that taking all (but one) cpus offline took 52 seconds (for a hundred
> and mumble logical cpus). Bringing them all back is just 4 seconds.
>
> Tested-by: Tony Luck <tony.luck@intel.com>

Unfortunately while it cures the livelock it's still not correct.

/me goes back to the drawing board

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