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-rw-r--r--arch/x86/kernel/cpu/resctrl/core.c11
-rw-r--r--arch/x86/kernel/cpu/resctrl/internal.h30
-rw-r--r--arch/x86/kernel/cpu/resctrl/rdtgroup.c53
3 files changed, 87 insertions, 7 deletions
diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index 1c00f2f0bf0c..9e1712e8aef7 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -273,6 +273,12 @@ static bool __get_mem_config_intel(struct rdt_resource *r)
}
r->data_width = 3;
+ if (boot_cpu_has(X86_FEATURE_PER_THREAD_MBA))
+ r->membw.throttle_mode = THREAD_THROTTLE_PER_THREAD;
+ else
+ r->membw.throttle_mode = THREAD_THROTTLE_MAX;
+ thread_throttle_mode_init();
+
r->alloc_capable = true;
r->alloc_enabled = true;
@@ -293,6 +299,11 @@ static bool __rdt_get_mem_config_amd(struct rdt_resource *r)
r->membw.delay_linear = false;
r->membw.arch_needs_linear = false;
+ /*
+ * AMD does not use memory delay throttle model to control
+ * the allocation like Intel does.
+ */
+ r->membw.throttle_mode = THREAD_THROTTLE_UNDEFINED;
r->membw.min_bw = 0;
r->membw.bw_gran = 1;
/* Max value is 2048, Data width should be 4 in decimal */
diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index 0b4829484c9e..80fa997fae60 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -372,21 +372,38 @@ struct rdt_cache {
};
/**
+ * enum membw_throttle_mode - System's memory bandwidth throttling mode
+ * @THREAD_THROTTLE_UNDEFINED: Not relevant to the system
+ * @THREAD_THROTTLE_MAX: Memory bandwidth is throttled at the core
+ * always using smallest bandwidth percentage
+ * assigned to threads, aka "max throttling"
+ * @THREAD_THROTTLE_PER_THREAD: Memory bandwidth is throttled at the thread
+ */
+enum membw_throttle_mode {
+ THREAD_THROTTLE_UNDEFINED = 0,
+ THREAD_THROTTLE_MAX,
+ THREAD_THROTTLE_PER_THREAD,
+};
+
+/**
* struct rdt_membw - Memory bandwidth allocation related data
* @min_bw: Minimum memory bandwidth percentage user can request
* @bw_gran: Granularity at which the memory bandwidth is allocated
* @delay_linear: True if memory B/W delay is in linear scale
* @arch_needs_linear: True if we can't configure non-linear resources
+ * @throttle_mode: Bandwidth throttling mode when threads request
+ * different memory bandwidths
* @mba_sc: True if MBA software controller(mba_sc) is enabled
* @mb_map: Mapping of memory B/W percentage to memory B/W delay
*/
struct rdt_membw {
- u32 min_bw;
- u32 bw_gran;
- u32 delay_linear;
- bool arch_needs_linear;
- bool mba_sc;
- u32 *mb_map;
+ u32 min_bw;
+ u32 bw_gran;
+ u32 delay_linear;
+ bool arch_needs_linear;
+ enum membw_throttle_mode throttle_mode;
+ bool mba_sc;
+ u32 *mb_map;
};
static inline bool is_llc_occupancy_enabled(void)
@@ -607,5 +624,6 @@ void cqm_handle_limbo(struct work_struct *work);
bool has_busy_rmid(struct rdt_resource *r, struct rdt_domain *d);
void __check_limbo(struct rdt_domain *d, bool force_free);
void rdt_domain_reconfigure_cdp(struct rdt_resource *r);
+void __init thread_throttle_mode_init(void);
#endif /* _ASM_X86_RESCTRL_INTERNAL_H */
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 78f3be10e215..b494187632b2 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -1027,6 +1027,19 @@ static int max_threshold_occ_show(struct kernfs_open_file *of,
return 0;
}
+static int rdt_thread_throttle_mode_show(struct kernfs_open_file *of,
+ struct seq_file *seq, void *v)
+{
+ struct rdt_resource *r = of->kn->parent->priv;
+
+ if (r->membw.throttle_mode == THREAD_THROTTLE_PER_THREAD)
+ seq_puts(seq, "per-thread\n");
+ else
+ seq_puts(seq, "max\n");
+
+ return 0;
+}
+
static ssize_t max_threshold_occ_write(struct kernfs_open_file *of,
char *buf, size_t nbytes, loff_t off)
{
@@ -1523,6 +1536,17 @@ static struct rftype res_common_files[] = {
.seq_show = rdt_delay_linear_show,
.fflags = RF_CTRL_INFO | RFTYPE_RES_MB,
},
+ /*
+ * Platform specific which (if any) capabilities are provided by
+ * thread_throttle_mode. Defer "fflags" initialization to platform
+ * discovery.
+ */
+ {
+ .name = "thread_throttle_mode",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = rdt_thread_throttle_mode_show,
+ },
{
.name = "max_threshold_occupancy",
.mode = 0644,
@@ -1593,7 +1617,7 @@ static int rdtgroup_add_files(struct kernfs_node *kn, unsigned long fflags)
lockdep_assert_held(&rdtgroup_mutex);
for (rft = rfts; rft < rfts + len; rft++) {
- if ((fflags & rft->fflags) == rft->fflags) {
+ if (rft->fflags && ((fflags & rft->fflags) == rft->fflags)) {
ret = rdtgroup_add_file(kn, rft);
if (ret)
goto error;
@@ -1610,6 +1634,33 @@ error:
return ret;
}
+static struct rftype *rdtgroup_get_rftype_by_name(const char *name)
+{
+ struct rftype *rfts, *rft;
+ int len;
+
+ rfts = res_common_files;
+ len = ARRAY_SIZE(res_common_files);
+
+ for (rft = rfts; rft < rfts + len; rft++) {
+ if (!strcmp(rft->name, name))
+ return rft;
+ }
+
+ 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 = RF_CTRL_INFO | RFTYPE_RES_MB;
+}
+
/**
* rdtgroup_kn_mode_restrict - Restrict user access to named resctrl file
* @r: The resource group with which the file is associated.