diff options
| author | Tony Luck <[email protected]> | 2024-06-28 14:56:07 -0700 |
|---|---|---|
| committer | Borislav Petkov (AMD) <[email protected]> | 2024-07-02 19:49:54 +0200 |
| commit | ac20aa423052553c005089b00f1e3caf79d3c1d3 (patch) | |
| tree | 2abbf5378ba3c5ac9b3195354f5cc92dbf8516ae | |
| parent | e13db55b5a0d447dea63cde772c1078405bbbf96 (diff) | |
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 <[email protected]>
Signed-off-by: Borislav Petkov (AMD) <[email protected]>
Reviewed-by: Reinette Chatre <[email protected]>
Tested-by: Babu Moger <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
| -rw-r--r-- | arch/x86/kernel/cpu/resctrl/rdtgroup.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index eb3bbfa96d5a..d3b0fa958266 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -2335,14 +2335,18 @@ static void mba_sc_domain_destroy(struct rdt_resource *r, /* * MBA software controller is supported only if - * MBM is supported and MBA is in linear scale. + * MBM is supported and MBA is in linear scale, + * and the MBM monitor scope is the same as MBA + * control scope. */ static bool supports_mba_mbps(void) { + struct rdt_resource *rmbm = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl; struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_MBA].r_resctrl; return (is_mbm_local_enabled() && - r->alloc_capable && is_mba_linear()); + r->alloc_capable && is_mba_linear() && + r->ctrl_scope == rmbm->mon_scope); } /* @@ -2750,6 +2754,7 @@ static int rdt_parse_param(struct fs_context *fc, struct fs_parameter *param) { struct rdt_fs_context *ctx = rdt_fc2context(fc); struct fs_parse_result result; + const char *msg; int opt; opt = fs_parse(fc, rdt_fs_parameters, param, &result); @@ -2764,8 +2769,9 @@ static int rdt_parse_param(struct fs_context *fc, struct fs_parameter *param) ctx->enable_cdpl2 = true; return 0; case Opt_mba_mbps: + msg = "mba_MBps requires local MBM and linear scale MBA at L3 scope"; if (!supports_mba_mbps()) - return -EINVAL; + return invalfc(fc, msg); ctx->enable_mba_mbps = true; return 0; case Opt_debug: |