• Reinette Chatre's avatar
    x86/intel_rdt: Make CPU information accessible for pseudo-locked regions · 33dc3e41
    Reinette Chatre authored
    When a resource group enters pseudo-locksetup mode it reflects that the
    platform supports cache pseudo-locking and the resource group is unused,
    ready to be used for a pseudo-locked region. Until it is set up as a
    pseudo-locked region the resource group is "locked down" such that no new
    tasks or cpus can be assigned to it. This is accomplished in a user visible
    way by making the cpus, cpus_list, and tasks resctrl files inaccassible
    (user cannot read from or write to these files).
    
    When the resource group changes to pseudo-locked mode it represents a cache
    pseudo-locked region. While not appropriate to make any changes to the cpus
    assigned to this region it is useful to make it easy for the user to see
    which cpus are associated with the pseudo-locked region.
    
    Modify the permissions of the cpus/cpus_list file when the resource group
    changes to pseudo-locked mode to support reading (not writing).  The
    information presented to the user when reading the file are the cpus
    associated with the pseudo-locked region.
    Signed-off-by: default avatarReinette Chatre <reinette.chatre@intel.com>
    Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
    Cc: fenghua.yu@intel.com
    Cc: tony.luck@intel.com
    Cc: vikas.shivappa@linux.intel.com
    Cc: gavin.hindman@intel.com
    Cc: jithu.joseph@intel.com
    Cc: dave.hansen@intel.com
    Cc: hpa@zytor.com
    Link: https://lkml.kernel.org/r/12756b7963b6abc1bffe8fb560b87b75da827bd1.1530421961.git.reinette.chatre@intel.com
    33dc3e41
intel_rdt_rdtgroup.c 70 KB