Add the 'mbm_soft_rmid' mount option to enable soft RMIDs.
This requires adding a mechanism for disabling a monitoring event at mount time to prevent the llc_occupancy event from being presented to the user.
Signed-off-by: Peter Newman peternewman@google.com --- arch/x86/kernel/cpu/resctrl/internal.h | 3 ++ arch/x86/kernel/cpu/resctrl/rdtgroup.c | 51 ++++++++++++++++++++++++++ 2 files changed, 54 insertions(+)
diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h index e6ff31a4dbc4..604e3d550601 100644 --- a/arch/x86/kernel/cpu/resctrl/internal.h +++ b/arch/x86/kernel/cpu/resctrl/internal.h @@ -59,6 +59,7 @@ struct rdt_fs_context { bool enable_cdpl2; bool enable_cdpl3; bool enable_mba_mbps; + bool enable_mbm_soft_rmid; };
static inline struct rdt_fs_context *rdt_fc2context(struct fs_context *fc) @@ -76,12 +77,14 @@ DECLARE_STATIC_KEY_FALSE(rdt_mon_enable_key); * @evtid: event id * @name: name of the event * @configurable: true if the event is configurable + * @enabled: true if event is disabled * @list: entry in &rdt_resource->evt_list */ struct mon_evt { enum resctrl_event_id evtid; char *name; bool configurable; + bool disabled; struct list_head list; };
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index c10f4798156a..c2abf69c2dcf 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -1013,6 +1013,8 @@ static int rdt_mon_features_show(struct kernfs_open_file *of, struct mon_evt *mevt;
list_for_each_entry(mevt, &r->evt_list, list) { + if (mevt->disabled) + continue; seq_printf(seq, "%s\n", mevt->name); if (mevt->configurable) seq_printf(seq, "%s_config\n", mevt->name); @@ -2204,6 +2206,37 @@ static bool supports_mba_mbps(void) r->alloc_capable && is_mba_linear()); }
+static bool supports_mbm_soft_rmid(void) +{ + return is_mbm_enabled(); +} + +int set_mbm_soft_rmid(bool mbm_soft_rmid) +{ + struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl; + struct mon_evt *mevt = NULL; + + /* + * is_llc_occupancy_enabled() will always return false when disabling, + * so search for the llc_occupancy event unconditionally. + */ + list_for_each_entry(mevt, &r->evt_list, list) { + if (strcmp(mevt->name, "llc_occupancy") == 0) { + mevt->disabled = mbm_soft_rmid; + break; + } + } + + rdt_mon_soft_rmid = mbm_soft_rmid; + + if (mbm_soft_rmid) + static_branch_enable_cpuslocked(&rdt_soft_rmid_enable_key); + else + static_branch_disable_cpuslocked(&rdt_soft_rmid_enable_key); + + return 0; +} + /* * Enable or disable the MBA software controller * which helps user specify bandwidth in MBps. @@ -2359,6 +2392,9 @@ static int rdt_enable_ctx(struct rdt_fs_context *ctx) if (!ret && ctx->enable_mba_mbps) ret = set_mba_sc(true);
+ if (!ret && ctx->enable_mbm_soft_rmid) + ret = set_mbm_soft_rmid(true); + return ret; }
@@ -2534,6 +2570,8 @@ static int rdt_get_tree(struct fs_context *fc) out_mba: if (ctx->enable_mba_mbps) set_mba_sc(false); + if (ctx->enable_mbm_soft_rmid) + set_mbm_soft_rmid(false); out_cdp: cdp_disable_all(); out: @@ -2547,6 +2585,7 @@ enum rdt_param { Opt_cdp, Opt_cdpl2, Opt_mba_mbps, + Opt_mbm_soft_rmid, nr__rdt_params };
@@ -2554,6 +2593,7 @@ static const struct fs_parameter_spec rdt_fs_parameters[] = { fsparam_flag("cdp", Opt_cdp), fsparam_flag("cdpl2", Opt_cdpl2), fsparam_flag("mba_MBps", Opt_mba_mbps), + fsparam_flag("mbm_soft_rmid", Opt_mbm_soft_rmid), {} };
@@ -2579,6 +2619,11 @@ static int rdt_parse_param(struct fs_context *fc, struct fs_parameter *param) return -EINVAL; ctx->enable_mba_mbps = true; return 0; + case Opt_mbm_soft_rmid: + if (!supports_mbm_soft_rmid()) + return -EINVAL; + ctx->enable_mbm_soft_rmid = true; + return 0; }
return -EINVAL; @@ -2767,6 +2812,7 @@ static void rdt_kill_sb(struct super_block *sb) cpus_read_lock(); mutex_lock(&rdtgroup_mutex);
+ set_mbm_soft_rmid(false); set_mba_sc(false);
/*Put everything back to default values. */ @@ -2861,6 +2907,8 @@ static int mkdir_mondata_subdir(struct kernfs_node *parent_kn, priv.u.rid = r->rid; priv.u.domid = d->id; list_for_each_entry(mevt, &r->evt_list, list) { + if (mevt->disabled) + continue; priv.u.evtid = mevt->evtid; ret = mon_addfile(kn, mevt->name, priv.priv); if (ret) @@ -3517,6 +3565,9 @@ static int rdtgroup_show_options(struct seq_file *seq, struct kernfs_root *kf) if (is_mba_sc(&rdt_resources_all[RDT_RESOURCE_MBA].r_resctrl)) seq_puts(seq, ",mba_MBps");
+ if (static_branch_likely(&rdt_soft_rmid_enable_key)) + seq_puts(seq, ",mbm_soft_rmid"); + return 0; }