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MPAM has an error interrupt which indicates > the MPAM driver has gone haywire. Should this occur tasks could run with > the wrong control values, leading to bad performance for important tasks. > In this scenario the MPAM driver will reset the hardware, but it needs > a way to tell resctrl that no further configuration should be attempted. > > In particular, moving tasks between control or monitor groups does not > interact with the architecture code, so there is no opportunity for the > arch code to indicate that the hardware is no-longer functioning. > > Using resctrl_exit() for this leaves the system in a funny state as > resctrl is still mounted, but cannot be un-mounted because the sysfs > directory that is typically used has been removed. Dave Martin suggests > this may cause systemd trouble in the future as not all filesystems > can be unmounted. > > Add calls to remove all the files and directories in resctrl, and > remove the sysfs_remove_mount_point() call that leaves the system > in a funny state. When triggered, this causes all the resctrl files > to disappear. resctrl can be unmounted, but not mounted again. > > Signed-off-by: James Morse > Tested-by: Carl Worth # arm64 > Tested-by: Shaopeng Tan > Tested-by: Peter Newman > Tested-by: Amit Singh Tomar # arm64 > Tested-by: Shanker Donthineni # arm64 > Tested-by: Babu Moger > Reviewed-by: Shaopeng Tan > Reviewed-by: Tony Luck > Reviewed-by: Reinette Chatre Reviewed-by: Fenghua Yu Thanks. -Fenghua