x86/resctrl: Block use of mba_MBps mount option on Sub-NUMA Cluster (SNC) systems
authorTony Luck <tony.luck@intel.com>
Fri, 28 Jun 2024 21:56:07 +0000 (14:56 -0700)
committerBorislav Petkov (AMD) <bp@alien8.de>
Tue, 2 Jul 2024 17:49:54 +0000 (19:49 +0200)
commitac20aa423052553c005089b00f1e3caf79d3c1d3
tree2abbf5378ba3c5ac9b3195354f5cc92dbf8516ae
parente13db55b5a0d447dea63cde772c1078405bbbf96
x86/resctrl: Block use of mba_MBps mount option on Sub-NUMA Cluster (SNC) systems

When SNC is enabled there is a mismatch between the MBA control function
which operates at L3 cache scope and the MBM monitor functions which
measure memory bandwidth on each SNC node.

Block use of the mba_MBps when scopes for MBA/MBM do not match.

Improve user diagnostics by adding invalfc() message when mba_MBps
is not supported.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Link: https://lore.kernel.org/r/20240628215619.76401-8-tony.luck@intel.com
arch/x86/kernel/cpu/resctrl/rdtgroup.c