#include <linux/node.h>
#include <linux/sysfs.h>
#include <linux/dax.h>
+#include <linux/memory-tiers.h>
static u8 hmat_revision;
static int hmat_disable __initdata;
return NOTIFY_OK;
}
+static int hmat_set_default_dram_perf(void)
+{
+ int rc;
+ int nid, pxm;
+ struct memory_target *target;
+ struct node_hmem_attrs *attrs;
+
+ if (!default_dram_type)
+ return -EIO;
+
+ for_each_node_mask(nid, default_dram_type->nodes) {
+ pxm = node_to_pxm(nid);
+ target = find_mem_target(pxm);
+ if (!target)
+ continue;
+ attrs = &target->hmem_attrs[1];
+ rc = mt_set_default_dram_perf(nid, attrs, "ACPI HMAT");
+ if (rc)
+ return rc;
+ }
+
+ return 0;
+}
+
+static int hmat_calculate_adistance(struct notifier_block *self,
+ unsigned long nid, void *data)
+{
+ static DECLARE_BITMAP(p_nodes, MAX_NUMNODES);
+ struct memory_target *target;
+ struct node_hmem_attrs *perf;
+ int *adist = data;
+ int pxm;
+
+ pxm = node_to_pxm(nid);
+ target = find_mem_target(pxm);
+ if (!target)
+ return NOTIFY_OK;
+
+ mutex_lock(&target_lock);
+ hmat_update_target_attrs(target, p_nodes, 1);
+ mutex_unlock(&target_lock);
+
+ perf = &target->hmem_attrs[1];
+
+ if (mt_perf_to_adistance(perf, adist))
+ return NOTIFY_OK;
+
+ return NOTIFY_STOP;
+}
+
+static struct notifier_block hmat_adist_nb __meminitdata = {
+ .notifier_call = hmat_calculate_adistance,
+ .priority = 100,
+};
+
static __init void hmat_free_structures(void)
{
struct memory_target *target, *tnext;
hmat_register_targets();
/* Keep the table and structures if the notifier may use them */
- if (!hotplug_memory_notifier(hmat_callback, HMAT_CALLBACK_PRI))
- return 0;
+ if (hotplug_memory_notifier(hmat_callback, HMAT_CALLBACK_PRI))
+ goto out_put;
+
+ if (!hmat_set_default_dram_perf())
+ register_mt_adistance_algorithm(&hmat_adist_nb);
+
+ return 0;
out_put:
hmat_free_structures();
acpi_put_table(tbl);
struct kref kref;
};
+struct node_hmem_attrs;
+
#ifdef CONFIG_NUMA
extern bool numa_demotion_enabled;
+extern struct memory_dev_type *default_dram_type;
struct memory_dev_type *alloc_memory_type(int adistance);
void put_memory_type(struct memory_dev_type *memtype);
void init_node_memory_type(int node, struct memory_dev_type *default_type);
int register_mt_adistance_algorithm(struct notifier_block *nb);
int unregister_mt_adistance_algorithm(struct notifier_block *nb);
int mt_calc_adistance(int node, int *adist);
+int mt_set_default_dram_perf(int nid, struct node_hmem_attrs *perf,
+ const char *source);
+int mt_perf_to_adistance(struct node_hmem_attrs *perf, int *adist);
#ifdef CONFIG_MIGRATION
int next_demotion_node(int node);
void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets);
#else
#define numa_demotion_enabled false
+#define default_dram_type NULL
/*
* CONFIG_NUMA implementation returns non NULL error.
*/
{
return NOTIFY_DONE;
}
+
+static inline int mt_set_default_dram_perf(int nid, struct node_hmem_attrs *perf,
+ const char *source)
+{
+ return -EIO;
+}
+
+static inline int mt_perf_to_adistance(struct node_hmem_attrs *perf, int *adist)
+{
+ return -EIO;
+}
#endif /* CONFIG_NUMA */
#endif /* _LINUX_MEMORY_TIERS_H */
static DEFINE_MUTEX(memory_tier_lock);
static LIST_HEAD(memory_tiers);
static struct node_memory_type_map node_memory_types[MAX_NUMNODES];
-static struct memory_dev_type *default_dram_type;
+struct memory_dev_type *default_dram_type;
static struct bus_type memory_tier_subsys = {
.name = "memory_tiering",
static BLOCKING_NOTIFIER_HEAD(mt_adistance_algorithms);
+static bool default_dram_perf_error;
+static struct node_hmem_attrs default_dram_perf;
+static int default_dram_perf_ref_nid = NUMA_NO_NODE;
+static const char *default_dram_perf_ref_source;
+
static inline struct memory_tier *to_memory_tier(struct device *device)
{
return container_of(device, struct memory_tier, dev);
}
EXPORT_SYMBOL_GPL(clear_node_memory_type);
+static void dump_hmem_attrs(struct node_hmem_attrs *attrs, const char *prefix)
+{
+ pr_info(
+"%sread_latency: %u, write_latency: %u, read_bandwidth: %u, write_bandwidth: %u\n",
+ prefix, attrs->read_latency, attrs->write_latency,
+ attrs->read_bandwidth, attrs->write_bandwidth);
+}
+
+int mt_set_default_dram_perf(int nid, struct node_hmem_attrs *perf,
+ const char *source)
+{
+ int rc = 0;
+
+ mutex_lock(&memory_tier_lock);
+ if (default_dram_perf_error) {
+ rc = -EIO;
+ goto out;
+ }
+
+ if (perf->read_latency + perf->write_latency == 0 ||
+ perf->read_bandwidth + perf->write_bandwidth == 0) {
+ rc = -EINVAL;
+ goto out;
+ }
+
+ if (default_dram_perf_ref_nid == NUMA_NO_NODE) {
+ default_dram_perf = *perf;
+ default_dram_perf_ref_nid = nid;
+ default_dram_perf_ref_source = kstrdup(source, GFP_KERNEL);
+ goto out;
+ }
+
+ /*
+ * The performance of all default DRAM nodes is expected to be
+ * same (that is, the variation is less than 10%). And it
+ * will be used as base to calculate the abstract distance of
+ * other memory nodes.
+ */
+ if (abs(perf->read_latency - default_dram_perf.read_latency) * 10 >
+ default_dram_perf.read_latency ||
+ abs(perf->write_latency - default_dram_perf.write_latency) * 10 >
+ default_dram_perf.write_latency ||
+ abs(perf->read_bandwidth - default_dram_perf.read_bandwidth) * 10 >
+ default_dram_perf.read_bandwidth ||
+ abs(perf->write_bandwidth - default_dram_perf.write_bandwidth) * 10 >
+ default_dram_perf.write_bandwidth) {
+ pr_info(
+"memory-tiers: the performance of DRAM node %d mismatches that of the reference\n"
+"DRAM node %d.\n", nid, default_dram_perf_ref_nid);
+ pr_info(" performance of reference DRAM node %d:\n",
+ default_dram_perf_ref_nid);
+ dump_hmem_attrs(&default_dram_perf, " ");
+ pr_info(" performance of DRAM node %d:\n", nid);
+ dump_hmem_attrs(perf, " ");
+ pr_info(
+" disable default DRAM node performance based abstract distance algorithm.\n");
+ default_dram_perf_error = true;
+ rc = -EINVAL;
+ }
+
+out:
+ mutex_unlock(&memory_tier_lock);
+ return rc;
+}
+
+int mt_perf_to_adistance(struct node_hmem_attrs *perf, int *adist)
+{
+ if (default_dram_perf_error)
+ return -EIO;
+
+ if (default_dram_perf_ref_nid == NUMA_NO_NODE)
+ return -ENOENT;
+
+ if (perf->read_latency + perf->write_latency == 0 ||
+ perf->read_bandwidth + perf->write_bandwidth == 0)
+ return -EINVAL;
+
+ mutex_lock(&memory_tier_lock);
+ /*
+ * The abstract distance of a memory node is in direct proportion to
+ * its memory latency (read + write) and inversely proportional to its
+ * memory bandwidth (read + write). The abstract distance, memory
+ * latency, and memory bandwidth of the default DRAM nodes are used as
+ * the base.
+ */
+ *adist = MEMTIER_ADISTANCE_DRAM *
+ (perf->read_latency + perf->write_latency) /
+ (default_dram_perf.read_latency + default_dram_perf.write_latency) *
+ (default_dram_perf.read_bandwidth + default_dram_perf.write_bandwidth) /
+ (perf->read_bandwidth + perf->write_bandwidth);
+ mutex_unlock(&memory_tier_lock);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(mt_perf_to_adistance);
+
/**
* register_mt_adistance_algorithm() - Register memory tiering abstract distance algorithm
* @nb: The notifier block which describe the algorithm