[Skiboot] [PATCH] Disable fast-reset for POWER8

Stewart Smith stewart at linux.ibm.com
Fri May 3 17:39:49 AEST 2019


Stewart Smith <stewart at linux.ibm.com> writes:
> There is a bug with fast-reset when CPU cores are busy, which can be
> reproduced by running `stress` and then trying `reboot -ff` (this is
> what the op-test test cases FastRebootHostStress and
> FastRebootHostStressTorture do). What happens is the cores lock up,
> which isn't the best thing in the world when you want them to start
> executing instructions again.
>
> A workaround is to use instruction ramming, which while greatly
> increasing the reliability of fast-reset on p8, doesn't make it perfect.
>
> Instruction ramming is what pdbg was modified to do in order to have the
> sreset functionality work reliably on p8.
> pdbg patches: https://patchwork.ozlabs.org/project/pdbg/list/?series=96593&state=*
>
> Fixes: https://github.com/open-power/skiboot/issues/185
> Signed-off-by: Stewart Smith <stewart at linux.ibm.com>
> ---
>  core/platform.c | 11 +++++++++--
>  1 file changed, 9 insertions(+), 2 deletions(-)

Probably only makes Oliver half happy, but merged as of 14f709b8eeda7e9ea7169b782e981c908de92e10
-- 
Stewart Smith
OPAL Architect, IBM.



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