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 <[email protected]>
Unfortunately while it cures the livelock it's still not correct. /me goes back to the drawing board
