linux/arch/x86/kernel/cpu/resctrl
Fenghua Yu a0195f314a x86/resctrl: Don't move a task to the same resource group
Shakeel Butt reported in [1] that a user can request a task to be moved
to a resource group even if the task is already in the group. It just
wastes time to do the move operation which could be costly to send IPI
to a different CPU.

Add a sanity check to ensure that the move operation only happens when
the task is not already in the resource group.

[1] https://lore.kernel.org/lkml/CALvZod7E9zzHwenzf7objzGKsdBmVwTgEJ0nPgs0LUFU3SN5Pw@mail.gmail.com/

Fixes: e02737d5b8 ("x86/intel_rdt: Add tasks files")
Reported-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/962ede65d8e95be793cb61102cca37f7bb018e66.1608243147.git.reinette.chatre@intel.com
2021-01-08 09:08:03 +01:00
..
core.c - Add logic to correct MBM total and local values fixing errata SKX99 and BDF102 2020-12-14 13:53:17 -08:00
ctrlmondata.c x86/resctrl: Add struct rdt_cache::arch_has_{sparse, empty}_bitmaps 2020-08-19 10:41:40 +02:00
internal.h - Add logic to correct MBM total and local values fixing errata SKX99 and BDF102 2020-12-14 13:53:17 -08:00
Makefile x86/resctrl: Avoid confusion over the new X86_RESCTRL config 2019-02-02 10:34:52 +01:00
monitor.c - Add logic to correct MBM total and local values fixing errata SKX99 and BDF102 2020-12-14 13:53:17 -08:00
pseudo_lock_event.h
pseudo_lock.c mremap: don't allow MREMAP_DONTUNMAP on special_mappings and aio 2020-12-15 12:13:41 -08:00
rdtgroup.c x86/resctrl: Don't move a task to the same resource group 2021-01-08 09:08:03 +01:00