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authorLinus Torvalds <torvalds@linux-foundation.org>2025-01-21 08:31:04 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2025-01-21 08:31:04 -0800
commit3357d1d1f9157089d96c04f3258ebd7e29e47752 (patch)
treef6cd7203d2054a5d962a0f4002666df55a83fb8b
parentd80825ee4a34a1b108aee51cd0302be0ab7943fa (diff)
parentfaf6ef673787956ec4d33ac8bf56f8ea929abf37 (diff)
Merge tag 'x86_cache_for_v6.14_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 resource control updates from Borislav Petkov: - Extend resctrl with the capability of total memory bandwidth monitoring, thus accomodating systems which support only total but not local memory bandwidth monitoring. Add the respective new mount options - The usual cleanups * tag 'x86_cache_for_v6.14_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/resctrl: Document the new "mba_MBps_event" file x86/resctrl: Add write option to "mba_MBps_event" file x86/resctrl: Add "mba_MBps_event" file to CTRL_MON directories x86/resctrl: Make mba_sc use total bandwidth if local is not supported x86/resctrl: Compute memory bandwidth for all supported events x86/resctrl: Modify update_mba_bw() to use per CTRL_MON group event x86/resctrl: Prepare for per-CTRL_MON group mba_MBps control x86/resctrl: Introduce resctrl_file_fflags_init() to initialize fflags x86/resctrl: Use kthread_run_on_cpu()
-rw-r--r--Documentation/arch/x86/resctrl.rst10
-rw-r--r--arch/x86/kernel/cpu/resctrl/core.c9
-rw-r--r--arch/x86/kernel/cpu/resctrl/ctrlmondata.c70
-rw-r--r--arch/x86/kernel/cpu/resctrl/internal.h11
-rw-r--r--arch/x86/kernel/cpu/resctrl/monitor.c94
-rw-r--r--arch/x86/kernel/cpu/resctrl/pseudo_lock.c28
-rw-r--r--arch/x86/kernel/cpu/resctrl/rdtgroup.c43
7 files changed, 178 insertions, 87 deletions
diff --git a/Documentation/arch/x86/resctrl.rst b/Documentation/arch/x86/resctrl.rst
index a824affd741d1..6768fc1fad166 100644
--- a/Documentation/arch/x86/resctrl.rst
+++ b/Documentation/arch/x86/resctrl.rst
@@ -384,6 +384,16 @@ When monitoring is enabled all MON groups will also contain:
Available only with debug option. The identifier used by hardware
for the monitor group. On x86 this is the RMID.
+When the "mba_MBps" mount option is used all CTRL_MON groups will also contain:
+
+"mba_MBps_event":
+ Reading this file shows which memory bandwidth event is used
+ as input to the software feedback loop that keeps memory bandwidth
+ below the value specified in the schemata file. Writing the
+ name of one of the supported memory bandwidth events found in
+ /sys/fs/resctrl/info/L3_MON/mon_features changes the input
+ event.
+
Resource allocation rules
-------------------------
diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index b681c2e07dbf8..3d1735ed8d1ff 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -234,7 +234,9 @@ static __init bool __get_mem_config_intel(struct rdt_resource *r)
r->membw.throttle_mode = THREAD_THROTTLE_PER_THREAD;
else
r->membw.throttle_mode = THREAD_THROTTLE_MAX;
- thread_throttle_mode_init();
+
+ resctrl_file_fflags_init("thread_throttle_mode",
+ RFTYPE_CTRL_INFO | RFTYPE_RES_MB);
r->alloc_capable = true;
@@ -961,6 +963,11 @@ static __init bool get_rdt_mon_resources(void)
if (!rdt_mon_features)
return false;
+ if (is_mbm_local_enabled())
+ mba_mbps_default_event = QOS_L3_MBM_LOCAL_EVENT_ID;
+ else if (is_mbm_total_enabled())
+ mba_mbps_default_event = QOS_L3_MBM_TOTAL_EVENT_ID;
+
return !rdt_get_mon_l3_config(r);
}
diff --git a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
index 200d89a640270..536351159cc23 100644
--- a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
+++ b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
@@ -518,6 +518,76 @@ static int smp_mon_event_count(void *arg)
return 0;
}
+ssize_t rdtgroup_mba_mbps_event_write(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
+{
+ struct rdtgroup *rdtgrp;
+ int ret = 0;
+
+ /* Valid input requires a trailing newline */
+ if (nbytes == 0 || buf[nbytes - 1] != '\n')
+ return -EINVAL;
+ buf[nbytes - 1] = '\0';
+
+ rdtgrp = rdtgroup_kn_lock_live(of->kn);
+ if (!rdtgrp) {
+ rdtgroup_kn_unlock(of->kn);
+ return -ENOENT;
+ }
+ rdt_last_cmd_clear();
+
+ if (!strcmp(buf, "mbm_local_bytes")) {
+ if (is_mbm_local_enabled())
+ rdtgrp->mba_mbps_event = QOS_L3_MBM_LOCAL_EVENT_ID;
+ else
+ ret = -EINVAL;
+ } else if (!strcmp(buf, "mbm_total_bytes")) {
+ if (is_mbm_total_enabled())
+ rdtgrp->mba_mbps_event = QOS_L3_MBM_TOTAL_EVENT_ID;
+ else
+ ret = -EINVAL;
+ } else {
+ ret = -EINVAL;
+ }
+
+ if (ret)
+ rdt_last_cmd_printf("Unsupported event id '%s'\n", buf);
+
+ rdtgroup_kn_unlock(of->kn);
+
+ return ret ?: nbytes;
+}
+
+int rdtgroup_mba_mbps_event_show(struct kernfs_open_file *of,
+ struct seq_file *s, void *v)
+{
+ struct rdtgroup *rdtgrp;
+ int ret = 0;
+
+ rdtgrp = rdtgroup_kn_lock_live(of->kn);
+
+ if (rdtgrp) {
+ switch (rdtgrp->mba_mbps_event) {
+ case QOS_L3_MBM_LOCAL_EVENT_ID:
+ seq_puts(s, "mbm_local_bytes\n");
+ break;
+ case QOS_L3_MBM_TOTAL_EVENT_ID:
+ seq_puts(s, "mbm_total_bytes\n");
+ break;
+ default:
+ pr_warn_once("Bad event %d\n", rdtgrp->mba_mbps_event);
+ ret = -EINVAL;
+ break;
+ }
+ } else {
+ ret = -ENOENT;
+ }
+
+ rdtgroup_kn_unlock(of->kn);
+
+ return ret;
+}
+
void mon_event_read(struct rmid_read *rr, struct rdt_resource *r,
struct rdt_mon_domain *d, struct rdtgroup *rdtgrp,
cpumask_t *cpumask, int evtid, int first)
diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index 955999aecfca9..20c898f09b7e7 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -283,6 +283,7 @@ struct pseudo_lock_region {
* monitor only or ctrl_mon group
* @mon: mongroup related data
* @mode: mode of resource group
+ * @mba_mbps_event: input monitoring event id when mba_sc is enabled
* @plr: pseudo-locked region
*/
struct rdtgroup {
@@ -295,6 +296,7 @@ struct rdtgroup {
enum rdt_group_type type;
struct mongroup mon;
enum rdtgrp_mode mode;
+ enum resctrl_event_id mba_mbps_event;
struct pseudo_lock_region *plr;
};
@@ -508,6 +510,7 @@ extern struct mutex rdtgroup_mutex;
extern struct rdt_hw_resource rdt_resources_all[];
extern struct rdtgroup rdtgroup_default;
extern struct dentry *debugfs_resctrl;
+extern enum resctrl_event_id mba_mbps_default_event;
enum resctrl_res_level {
RDT_RESOURCE_L3,
@@ -607,6 +610,10 @@ ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of,
char *buf, size_t nbytes, loff_t off);
int rdtgroup_schemata_show(struct kernfs_open_file *of,
struct seq_file *s, void *v);
+ssize_t rdtgroup_mba_mbps_event_write(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off);
+int rdtgroup_mba_mbps_event_show(struct kernfs_open_file *of,
+ struct seq_file *s, void *v);
bool rdtgroup_cbm_overlaps(struct resctrl_schema *s, struct rdt_ctrl_domain *d,
unsigned long cbm, int closid, bool exclusive);
unsigned int rdtgroup_cbm_to_size(struct rdt_resource *r, struct rdt_ctrl_domain *d,
@@ -647,10 +654,8 @@ void cqm_handle_limbo(struct work_struct *work);
bool has_busy_rmid(struct rdt_mon_domain *d);
void __check_limbo(struct rdt_mon_domain *d, bool force_free);
void rdt_domain_reconfigure_cdp(struct rdt_resource *r);
-void __init thread_throttle_mode_init(void);
-void __init mbm_config_rftype_init(const char *config);
+void resctrl_file_fflags_init(const char *config, unsigned long fflags);
void rdt_staged_configs_clear(void);
bool closid_allocated(unsigned int closid);
int resctrl_find_cleanest_closid(void);
-
#endif /* _ASM_X86_RESCTRL_INTERNAL_H */
diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
index 5fcb3d635d915..94a1d97804614 100644
--- a/arch/x86/kernel/cpu/resctrl/monitor.c
+++ b/arch/x86/kernel/cpu/resctrl/monitor.c
@@ -663,9 +663,12 @@ static int __mon_event_count(u32 closid, u32 rmid, struct rmid_read *rr)
*/
static void mbm_bw_count(u32 closid, u32 rmid, struct rmid_read *rr)
{
- u32 idx = resctrl_arch_rmid_idx_encode(closid, rmid);
- struct mbm_state *m = &rr->d->mbm_local[idx];
u64 cur_bw, bytes, cur_bytes;
+ struct mbm_state *m;
+
+ m = get_mbm_state(rr->d, closid, rmid, rr->evtid);
+ if (WARN_ON_ONCE(!m))
+ return;
cur_bytes = rr->val;
bytes = cur_bytes - m->prev_bw_bytes;
@@ -752,20 +755,20 @@ static void update_mba_bw(struct rdtgroup *rgrp, struct rdt_mon_domain *dom_mbm)
u32 closid, rmid, cur_msr_val, new_msr_val;
struct mbm_state *pmbm_data, *cmbm_data;
struct rdt_ctrl_domain *dom_mba;
+ enum resctrl_event_id evt_id;
struct rdt_resource *r_mba;
- u32 cur_bw, user_bw, idx;
struct list_head *head;
struct rdtgroup *entry;
-
- if (!is_mbm_local_enabled())
- return;
+ u32 cur_bw, user_bw;
r_mba = &rdt_resources_all[RDT_RESOURCE_MBA].r_resctrl;
+ evt_id = rgrp->mba_mbps_event;
closid = rgrp->closid;
rmid = rgrp->mon.rmid;
- idx = resctrl_arch_rmid_idx_encode(closid, rmid);
- pmbm_data = &dom_mbm->mbm_local[idx];
+ pmbm_data = get_mbm_state(dom_mbm, closid, rmid, evt_id);
+ if (WARN_ON_ONCE(!pmbm_data))
+ return;
dom_mba = get_ctrl_domain_from_cpu(smp_processor_id(), r_mba);
if (!dom_mba) {
@@ -784,7 +787,9 @@ static void update_mba_bw(struct rdtgroup *rgrp, struct rdt_mon_domain *dom_mbm)
*/
head = &rgrp->mon.crdtgrp_list;
list_for_each_entry(entry, head, mon.crdtgrp_list) {
- cmbm_data = &dom_mbm->mbm_local[entry->mon.rmid];
+ cmbm_data = get_mbm_state(dom_mbm, entry->closid, entry->mon.rmid, evt_id);
+ if (WARN_ON_ONCE(!cmbm_data))
+ return;
cur_bw += cmbm_data->prev_bw;
}
@@ -813,54 +818,45 @@ static void update_mba_bw(struct rdtgroup *rgrp, struct rdt_mon_domain *dom_mbm)
resctrl_arch_update_one(r_mba, dom_mba, closid, CDP_NONE, new_msr_val);
}
-static void mbm_update(struct rdt_resource *r, struct rdt_mon_domain *d,
- u32 closid, u32 rmid)
+static void mbm_update_one_event(struct rdt_resource *r, struct rdt_mon_domain *d,
+ u32 closid, u32 rmid, enum resctrl_event_id evtid)
{
struct rmid_read rr = {0};
rr.r = r;
rr.d = d;
+ rr.evtid = evtid;
+ rr.arch_mon_ctx = resctrl_arch_mon_ctx_alloc(rr.r, rr.evtid);
+ if (IS_ERR(rr.arch_mon_ctx)) {
+ pr_warn_ratelimited("Failed to allocate monitor context: %ld",
+ PTR_ERR(rr.arch_mon_ctx));
+ return;
+ }
+
+ __mon_event_count(closid, rmid, &rr);
/*
- * This is protected from concurrent reads from user
- * as both the user and we hold the global mutex.
+ * If the software controller is enabled, compute the
+ * bandwidth for this event id.
*/
- if (is_mbm_total_enabled()) {
- rr.evtid = QOS_L3_MBM_TOTAL_EVENT_ID;
- rr.val = 0;
- rr.arch_mon_ctx = resctrl_arch_mon_ctx_alloc(rr.r, rr.evtid);
- if (IS_ERR(rr.arch_mon_ctx)) {
- pr_warn_ratelimited("Failed to allocate monitor context: %ld",
- PTR_ERR(rr.arch_mon_ctx));
- return;
- }
-
- __mon_event_count(closid, rmid, &rr);
+ if (is_mba_sc(NULL))
+ mbm_bw_count(closid, rmid, &rr);
- resctrl_arch_mon_ctx_free(rr.r, rr.evtid, rr.arch_mon_ctx);
- }
- if (is_mbm_local_enabled()) {
- rr.evtid = QOS_L3_MBM_LOCAL_EVENT_ID;
- rr.val = 0;
- rr.arch_mon_ctx = resctrl_arch_mon_ctx_alloc(rr.r, rr.evtid);
- if (IS_ERR(rr.arch_mon_ctx)) {
- pr_warn_ratelimited("Failed to allocate monitor context: %ld",
- PTR_ERR(rr.arch_mon_ctx));
- return;
- }
-
- __mon_event_count(closid, rmid, &rr);
+ resctrl_arch_mon_ctx_free(rr.r, rr.evtid, rr.arch_mon_ctx);
+}
- /*
- * Call the MBA software controller only for the
- * control groups and when user has enabled
- * the software controller explicitly.
- */
- if (is_mba_sc(NULL))
- mbm_bw_count(closid, rmid, &rr);
+static void mbm_update(struct rdt_resource *r, struct rdt_mon_domain *d,
+ u32 closid, u32 rmid)
+{
+ /*
+ * This is protected from concurrent reads from user as both
+ * the user and overflow handler hold the global mutex.
+ */
+ if (is_mbm_total_enabled())
+ mbm_update_one_event(r, d, closid, rmid, QOS_L3_MBM_TOTAL_EVENT_ID);
- resctrl_arch_mon_ctx_free(rr.r, rr.evtid, rr.arch_mon_ctx);
- }
+ if (is_mbm_local_enabled())
+ mbm_update_one_event(r, d, closid, rmid, QOS_L3_MBM_LOCAL_EVENT_ID);
}
/*
@@ -1224,11 +1220,13 @@ int __init rdt_get_mon_l3_config(struct rdt_resource *r)
if (rdt_cpu_has(X86_FEATURE_CQM_MBM_TOTAL)) {
mbm_total_event.configurable = true;
- mbm_config_rftype_init("mbm_total_bytes_config");
+ resctrl_file_fflags_init("mbm_total_bytes_config",
+ RFTYPE_MON_INFO | RFTYPE_RES_CACHE);
}
if (rdt_cpu_has(X86_FEATURE_CQM_MBM_LOCAL)) {
mbm_local_event.configurable = true;
- mbm_config_rftype_init("mbm_local_bytes_config");
+ resctrl_file_fflags_init("mbm_local_bytes_config",
+ RFTYPE_MON_INFO | RFTYPE_RES_CACHE);
}
}
diff --git a/arch/x86/kernel/cpu/resctrl/pseudo_lock.c b/arch/x86/kernel/cpu/resctrl/pseudo_lock.c
index 972e6b6b0481f..6c60c16a9dd03 100644
--- a/arch/x86/kernel/cpu/resctrl/pseudo_lock.c
+++ b/arch/x86/kernel/cpu/resctrl/pseudo_lock.c
@@ -1205,20 +1205,14 @@ static int pseudo_lock_measure_cycles(struct rdtgroup *rdtgrp, int sel)
plr->cpu = cpu;
if (sel == 1)
- thread = kthread_create_on_node(measure_cycles_lat_fn, plr,
- cpu_to_node(cpu),
- "pseudo_lock_measure/%u",
- cpu);
+ thread = kthread_run_on_cpu(measure_cycles_lat_fn, plr,
+ cpu, "pseudo_lock_measure/%u");
else if (sel == 2)
- thread = kthread_create_on_node(measure_l2_residency, plr,
- cpu_to_node(cpu),
- "pseudo_lock_measure/%u",
- cpu);
+ thread = kthread_run_on_cpu(measure_l2_residency, plr,
+ cpu, "pseudo_lock_measure/%u");
else if (sel == 3)
- thread = kthread_create_on_node(measure_l3_residency, plr,
- cpu_to_node(cpu),
- "pseudo_lock_measure/%u",
- cpu);
+ thread = kthread_run_on_cpu(measure_l3_residency, plr,
+ cpu, "pseudo_lock_measure/%u");
else
goto out;
@@ -1226,8 +1220,6 @@ static int pseudo_lock_measure_cycles(struct rdtgroup *rdtgrp, int sel)
ret = PTR_ERR(thread);
goto out;
}
- kthread_bind(thread, cpu);
- wake_up_process(thread);
ret = wait_event_interruptible(plr->lock_thread_wq,
plr->thread_done == 1);
@@ -1315,18 +1307,14 @@ int rdtgroup_pseudo_lock_create(struct rdtgroup *rdtgrp)
plr->thread_done = 0;
- thread = kthread_create_on_node(pseudo_lock_fn, rdtgrp,
- cpu_to_node(plr->cpu),
- "pseudo_lock/%u", plr->cpu);
+ thread = kthread_run_on_cpu(pseudo_lock_fn, rdtgrp,
+ plr->cpu, "pseudo_lock/%u");
if (IS_ERR(thread)) {
ret = PTR_ERR(thread);
rdt_last_cmd_printf("Locking thread returned error %d\n", ret);
goto out_cstates;
}
- kthread_bind(thread, plr->cpu);
- wake_up_process(thread);
-
ret = wait_event_interruptible(plr->lock_thread_wq,
plr->thread_done == 1);
if (ret < 0) {
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index d906a1cd84917..6419e04d8a7b2 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -65,6 +65,15 @@ static void rdtgroup_destroy_root(void);
struct dentry *debugfs_resctrl;
+/*
+ * Memory bandwidth monitoring event to use for the default CTRL_MON group
+ * and each new CTRL_MON group created by the user. Only relevant when
+ * the filesystem is mounted with the "mba_MBps" option so it does not
+ * matter that it remains uninitialized on systems that do not support
+ * the "mba_MBps" option.
+ */
+enum resctrl_event_id mba_mbps_default_event;
+
static bool resctrl_debug;
void rdt_last_cmd_clear(void)
@@ -1942,6 +1951,13 @@ static struct rftype res_common_files[] = {
.fflags = RFTYPE_CTRL_BASE,
},
{
+ .name = "mba_MBps_event",
+ .mode = 0644,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .write = rdtgroup_mba_mbps_event_write,
+ .seq_show = rdtgroup_mba_mbps_event_show,
+ },
+ {
.name = "mode",
.mode = 0644,
.kf_ops = &rdtgroup_kf_single_ops,
@@ -2020,24 +2036,13 @@ static struct rftype *rdtgroup_get_rftype_by_name(const char *name)
return NULL;
}
-void __init thread_throttle_mode_init(void)
-{
- struct rftype *rft;
-
- rft = rdtgroup_get_rftype_by_name("thread_throttle_mode");
- if (!rft)
- return;
-
- rft->fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_MB;
-}
-
-void __init mbm_config_rftype_init(const char *config)
+void resctrl_file_fflags_init(const char *config, unsigned long fflags)
{
struct rftype *rft;
rft = rdtgroup_get_rftype_by_name(config);
if (rft)
- rft->fflags = RFTYPE_MON_INFO | RFTYPE_RES_CACHE;
+ rft->fflags = fflags;
}
/**
@@ -2343,7 +2348,7 @@ 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() &&
+ return (is_mbm_enabled() &&
r->alloc_capable && is_mba_linear() &&
r->ctrl_scope == rmbm->mon_scope);
}
@@ -2357,6 +2362,7 @@ static int set_mba_sc(bool mba_sc)
struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_MBA].r_resctrl;
u32 num_closid = resctrl_arch_get_num_closid(r);
struct rdt_ctrl_domain *d;
+ unsigned long fflags;
int i;
if (!supports_mba_mbps() || mba_sc == is_mba_sc(r))
@@ -2364,11 +2370,16 @@ static int set_mba_sc(bool mba_sc)
r->membw.mba_sc = mba_sc;
+ rdtgroup_default.mba_mbps_event = mba_mbps_default_event;
+
list_for_each_entry(d, &r->ctrl_domains, hdr.list) {
for (i = 0; i < num_closid; i++)
d->mbps_val[i] = MBA_MAX_MBPS;
}
+ fflags = mba_sc ? RFTYPE_CTRL_BASE | RFTYPE_MON_BASE : 0;
+ resctrl_file_fflags_init("mba_MBps_event", fflags);
+
return 0;
}
@@ -2768,7 +2779,7 @@ 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";
+ msg = "mba_MBps requires MBM and linear scale MBA at L3 scope";
if (!supports_mba_mbps())
return invalfc(fc, msg);
ctx->enable_mba_mbps = true;
@@ -3622,6 +3633,8 @@ static int rdtgroup_mkdir_ctrl_mon(struct kernfs_node *parent_kn,
rdt_last_cmd_puts("kernfs subdir error\n");
goto out_del_list;
}
+ if (is_mba_sc(NULL))
+ rdtgrp->mba_mbps_event = mba_mbps_default_event;
}
goto out_unlock;