| Message ID | 20240329004815.195476-3-horenchuang@bytedance.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Improved Memory Tier Creation for CPUless NUMA Nodes | expand |
"Ho-Ren (Jack) Chuang" <horenchuang@bytedance.com> writes: > The current implementation treats emulated memory devices, such as > CXL1.1 type3 memory, as normal DRAM when they are emulated as normal memory > (E820_TYPE_RAM). However, these emulated devices have different > characteristics than traditional DRAM, making it important to > distinguish them. Thus, we modify the tiered memory initialization process > to introduce a delay specifically for CPUless NUMA nodes. This delay > ensures that the memory tier initialization for these nodes is deferred > until HMAT information is obtained during the boot process. Finally, > demotion tables are recalculated at the end. > > * late_initcall(memory_tier_late_init); > Some device drivers may have initialized memory tiers between > `memory_tier_init()` and `memory_tier_late_init()`, potentially bringing > online memory nodes and configuring memory tiers. They should be excluded > in the late init. > > * Handle cases where there is no HMAT when creating memory tiers > There is a scenario where a CPUless node does not provide HMAT information. > If no HMAT is specified, it falls back to using the default DRAM tier. > > * Introduce another new lock `default_dram_perf_lock` for adist calculation > In the current implementation, iterating through CPUlist nodes requires > holding the `memory_tier_lock`. However, `mt_calc_adistance()` will end up > trying to acquire the same lock, leading to a potential deadlock. > Therefore, we propose introducing a standalone `default_dram_perf_lock` to > protect `default_dram_perf_*`. This approach not only avoids deadlock > but also prevents holding a large lock simultaneously. > > * Upgrade `set_node_memory_tier` to support additional cases, including > default DRAM, late CPUless, and hot-plugged initializations. > To cover hot-plugged memory nodes, `mt_calc_adistance()` and > `mt_find_alloc_memory_type()` are moved into `set_node_memory_tier()` to > handle cases where memtype is not initialized and where HMAT information is > available. > > * Introduce `default_memory_types` for those memory types that are not > initialized by device drivers. > Because late initialized memory and default DRAM memory need to be managed, > a default memory type is created for storing all memory types that are > not initialized by device drivers and as a fallback. > > Signed-off-by: Ho-Ren (Jack) Chuang <horenchuang@bytedance.com> > Signed-off-by: Hao Xiang <hao.xiang@bytedance.com> > Reviewed-by: "Huang, Ying" <ying.huang@intel.com> > --- > mm/memory-tiers.c | 94 +++++++++++++++++++++++++++++++++++++++-------- > 1 file changed, 78 insertions(+), 16 deletions(-) > > diff --git a/mm/memory-tiers.c b/mm/memory-tiers.c > index 974af10cfdd8..e24fc3bebae4 100644 > --- a/mm/memory-tiers.c > +++ b/mm/memory-tiers.c > @@ -36,6 +36,11 @@ struct node_memory_type_map { > > static DEFINE_MUTEX(memory_tier_lock); > static LIST_HEAD(memory_tiers); > +/* > + * The list is used to store all memory types that are not created > + * by a device driver. > + */ > +static LIST_HEAD(default_memory_types); > static struct node_memory_type_map node_memory_types[MAX_NUMNODES]; > struct memory_dev_type *default_dram_type; > > @@ -108,6 +113,8 @@ static struct demotion_nodes *node_demotion __read_mostly; > > static BLOCKING_NOTIFIER_HEAD(mt_adistance_algorithms); > > +/* The lock is used to protect `default_dram_perf*` info and nid. */ > +static DEFINE_MUTEX(default_dram_perf_lock); > static bool default_dram_perf_error; > static struct access_coordinate default_dram_perf; > static int default_dram_perf_ref_nid = NUMA_NO_NODE; > @@ -505,7 +512,8 @@ static inline void __init_node_memory_type(int node, struct memory_dev_type *mem > static struct memory_tier *set_node_memory_tier(int node) > { > struct memory_tier *memtier; > - struct memory_dev_type *memtype; > + struct memory_dev_type *mtype = default_dram_type; > + int adist = MEMTIER_ADISTANCE_DRAM; > pg_data_t *pgdat = NODE_DATA(node); > > > @@ -514,11 +522,20 @@ static struct memory_tier *set_node_memory_tier(int node) > if (!node_state(node, N_MEMORY)) > return ERR_PTR(-EINVAL); > > - __init_node_memory_type(node, default_dram_type); > + mt_calc_adistance(node, &adist); > + if (node_memory_types[node].memtype == NULL) { > + mtype = mt_find_alloc_memory_type(adist, &default_memory_types); > + if (IS_ERR(mtype)) { > + mtype = default_dram_type; > + pr_info("Failed to allocate a memory type. Fall back.\n"); > + } > + } > + > + __init_node_memory_type(node, mtype); > > - memtype = node_memory_types[node].memtype; > - node_set(node, memtype->nodes); > - memtier = find_create_memory_tier(memtype); > + mtype = node_memory_types[node].memtype; > + node_set(node, mtype->nodes); > + memtier = find_create_memory_tier(mtype); > if (!IS_ERR(memtier)) > rcu_assign_pointer(pgdat->memtier, memtier); > return memtier; > @@ -655,6 +672,34 @@ void mt_put_memory_types(struct list_head *memory_types) > } > EXPORT_SYMBOL_GPL(mt_put_memory_types); > > +/* > + * This is invoked via `late_initcall()` to initialize memory tiers for > + * CPU-less memory nodes after driver initialization, which is > + * expected to provide `adistance` algorithms. > + */ > +static int __init memory_tier_late_init(void) > +{ > + int nid; > + > + mutex_lock(&memory_tier_lock); > + for_each_node_state(nid, N_MEMORY) > + if (!node_state(nid, N_CPU) && It appears that you didn't notice my comments about this... https://lore.kernel.org/linux-mm/87v857kujp.fsf@yhuang6-desk2.ccr.corp.intel.com/ > + node_memory_types[nid].memtype == NULL) > + /* > + * Some device drivers may have initialized memory tiers > + * between `memory_tier_init()` and `memory_tier_late_init()`, > + * potentially bringing online memory nodes and > + * configuring memory tiers. Exclude them here. > + */ > + set_node_memory_tier(nid); > + > + establish_demotion_targets(); > + mutex_unlock(&memory_tier_lock); > + > + return 0; > +} > +late_initcall(memory_tier_late_init); > + > static void dump_hmem_attrs(struct access_coordinate *coord, const char *prefix) > { > pr_info( > @@ -668,7 +713,7 @@ int mt_set_default_dram_perf(int nid, struct access_coordinate *perf, > { > int rc = 0; > > - mutex_lock(&memory_tier_lock); > + mutex_lock(&default_dram_perf_lock); > if (default_dram_perf_error) { > rc = -EIO; > goto out; > @@ -716,23 +761,30 @@ int mt_set_default_dram_perf(int nid, struct access_coordinate *perf, > } > > out: > - mutex_unlock(&memory_tier_lock); > + mutex_unlock(&default_dram_perf_lock); > return rc; > } > > int mt_perf_to_adistance(struct access_coordinate *perf, int *adist) > { > - if (default_dram_perf_error) > - return -EIO; > + int rc = 0; > > - if (default_dram_perf_ref_nid == NUMA_NO_NODE) > - return -ENOENT; > + mutex_lock(&default_dram_perf_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) > - return -EINVAL; > + perf->read_bandwidth + perf->write_bandwidth == 0) { > + rc = -EINVAL; > + goto out; > + } > > - mutex_lock(&memory_tier_lock); > + if (default_dram_perf_ref_nid == NUMA_NO_NODE) { > + rc = -ENOENT; > + goto out; > + } > /* > * The abstract distance of a memory node is in direct proportion to > * its memory latency (read + write) and inversely proportional to its > @@ -745,8 +797,9 @@ int mt_perf_to_adistance(struct access_coordinate *perf, int *adist) > (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); > > +out: > + mutex_unlock(&default_dram_perf_lock); > return 0; > } > EXPORT_SYMBOL_GPL(mt_perf_to_adistance); > @@ -858,7 +911,8 @@ static int __init memory_tier_init(void) > * For now we can have 4 faster memory tiers with smaller adistance > * than default DRAM tier. > */ > - default_dram_type = alloc_memory_type(MEMTIER_ADISTANCE_DRAM); > + default_dram_type = mt_find_alloc_memory_type(MEMTIER_ADISTANCE_DRAM, > + &default_memory_types); > if (IS_ERR(default_dram_type)) > panic("%s() failed to allocate default DRAM tier\n", __func__); > > @@ -868,6 +922,14 @@ static int __init memory_tier_init(void) > * types assigned. > */ > for_each_node_state(node, N_MEMORY) { > + if (!node_state(node, N_CPU)) > + /* > + * Defer memory tier initialization on CPUless numa nodes. > + * These will be initialized after firmware and devices are > + * initialized. > + */ > + continue; > + > memtier = set_node_memory_tier(node); > if (IS_ERR(memtier)) > /* -- Best Regards, Huang, Ying
On Thu, Mar 28, 2024 at 5:59 PM Huang, Ying <ying.huang@intel.com> wrote: > > "Ho-Ren (Jack) Chuang" <horenchuang@bytedance.com> writes: > > > The current implementation treats emulated memory devices, such as > > CXL1.1 type3 memory, as normal DRAM when they are emulated as normal memory > > (E820_TYPE_RAM). However, these emulated devices have different > > characteristics than traditional DRAM, making it important to > > distinguish them. Thus, we modify the tiered memory initialization process > > to introduce a delay specifically for CPUless NUMA nodes. This delay > > ensures that the memory tier initialization for these nodes is deferred > > until HMAT information is obtained during the boot process. Finally, > > demotion tables are recalculated at the end. > > > > * late_initcall(memory_tier_late_init); > > Some device drivers may have initialized memory tiers between > > `memory_tier_init()` and `memory_tier_late_init()`, potentially bringing > > online memory nodes and configuring memory tiers. They should be excluded > > in the late init. > > > > * Handle cases where there is no HMAT when creating memory tiers > > There is a scenario where a CPUless node does not provide HMAT information. > > If no HMAT is specified, it falls back to using the default DRAM tier. > > > > * Introduce another new lock `default_dram_perf_lock` for adist calculation > > In the current implementation, iterating through CPUlist nodes requires > > holding the `memory_tier_lock`. However, `mt_calc_adistance()` will end up > > trying to acquire the same lock, leading to a potential deadlock. > > Therefore, we propose introducing a standalone `default_dram_perf_lock` to > > protect `default_dram_perf_*`. This approach not only avoids deadlock > > but also prevents holding a large lock simultaneously. > > > > * Upgrade `set_node_memory_tier` to support additional cases, including > > default DRAM, late CPUless, and hot-plugged initializations. > > To cover hot-plugged memory nodes, `mt_calc_adistance()` and > > `mt_find_alloc_memory_type()` are moved into `set_node_memory_tier()` to > > handle cases where memtype is not initialized and where HMAT information is > > available. > > > > * Introduce `default_memory_types` for those memory types that are not > > initialized by device drivers. > > Because late initialized memory and default DRAM memory need to be managed, > > a default memory type is created for storing all memory types that are > > not initialized by device drivers and as a fallback. > > > > Signed-off-by: Ho-Ren (Jack) Chuang <horenchuang@bytedance.com> > > Signed-off-by: Hao Xiang <hao.xiang@bytedance.com> > > Reviewed-by: "Huang, Ying" <ying.huang@intel.com> > > --- > > mm/memory-tiers.c | 94 +++++++++++++++++++++++++++++++++++++++-------- > > 1 file changed, 78 insertions(+), 16 deletions(-) > > > > diff --git a/mm/memory-tiers.c b/mm/memory-tiers.c > > index 974af10cfdd8..e24fc3bebae4 100644 > > --- a/mm/memory-tiers.c > > +++ b/mm/memory-tiers.c > > @@ -36,6 +36,11 @@ struct node_memory_type_map { > > > > static DEFINE_MUTEX(memory_tier_lock); > > static LIST_HEAD(memory_tiers); > > +/* > > + * The list is used to store all memory types that are not created > > + * by a device driver. > > + */ > > +static LIST_HEAD(default_memory_types); > > static struct node_memory_type_map node_memory_types[MAX_NUMNODES]; > > struct memory_dev_type *default_dram_type; > > > > @@ -108,6 +113,8 @@ static struct demotion_nodes *node_demotion __read_mostly; > > > > static BLOCKING_NOTIFIER_HEAD(mt_adistance_algorithms); > > > > +/* The lock is used to protect `default_dram_perf*` info and nid. */ > > +static DEFINE_MUTEX(default_dram_perf_lock); > > static bool default_dram_perf_error; > > static struct access_coordinate default_dram_perf; > > static int default_dram_perf_ref_nid = NUMA_NO_NODE; > > @@ -505,7 +512,8 @@ static inline void __init_node_memory_type(int node, struct memory_dev_type *mem > > static struct memory_tier *set_node_memory_tier(int node) > > { > > struct memory_tier *memtier; > > - struct memory_dev_type *memtype; > > + struct memory_dev_type *mtype = default_dram_type; > > + int adist = MEMTIER_ADISTANCE_DRAM; > > pg_data_t *pgdat = NODE_DATA(node); > > > > > > @@ -514,11 +522,20 @@ static struct memory_tier *set_node_memory_tier(int node) > > if (!node_state(node, N_MEMORY)) > > return ERR_PTR(-EINVAL); > > > > - __init_node_memory_type(node, default_dram_type); > > + mt_calc_adistance(node, &adist); > > + if (node_memory_types[node].memtype == NULL) { > > + mtype = mt_find_alloc_memory_type(adist, &default_memory_types); > > + if (IS_ERR(mtype)) { > > + mtype = default_dram_type; > > + pr_info("Failed to allocate a memory type. Fall back.\n"); > > + } > > + } > > + > > + __init_node_memory_type(node, mtype); > > > > - memtype = node_memory_types[node].memtype; > > - node_set(node, memtype->nodes); > > - memtier = find_create_memory_tier(memtype); > > + mtype = node_memory_types[node].memtype; > > + node_set(node, mtype->nodes); > > + memtier = find_create_memory_tier(mtype); > > if (!IS_ERR(memtier)) > > rcu_assign_pointer(pgdat->memtier, memtier); > > return memtier; > > @@ -655,6 +672,34 @@ void mt_put_memory_types(struct list_head *memory_types) > > } > > EXPORT_SYMBOL_GPL(mt_put_memory_types); > > > > +/* > > + * This is invoked via `late_initcall()` to initialize memory tiers for > > + * CPU-less memory nodes after driver initialization, which is > > + * expected to provide `adistance` algorithms. > > + */ > > +static int __init memory_tier_late_init(void) > > +{ > > + int nid; > > + > > + mutex_lock(&memory_tier_lock); > > + for_each_node_state(nid, N_MEMORY) > > + if (!node_state(nid, N_CPU) && > > It appears that you didn't notice my comments about this... > > https://lore.kernel.org/linux-mm/87v857kujp.fsf@yhuang6-desk2.ccr.corp.intel.com/ > Oops. I misunderstood your meaning. I will then replace -- if (!node_state(nid, N_CPU) && -- node_memory_types[nid].memtype == NULL) with ++ if (node_memory_types[nid].memtype == NULL)" > > + node_memory_types[nid].memtype == NULL) > > + /* > > + * Some device drivers may have initialized memory tiers > > + * between `memory_tier_init()` and `memory_tier_late_init()`, > > + * potentially bringing online memory nodes and > > + * configuring memory tiers. Exclude them here. > > + */ > > + set_node_memory_tier(nid); > > + > > + establish_demotion_targets(); > > + mutex_unlock(&memory_tier_lock); > > + > > + return 0; > > +} > > +late_initcall(memory_tier_late_init); > > + > > static void dump_hmem_attrs(struct access_coordinate *coord, const char *prefix) > > { > > pr_info( > > @@ -668,7 +713,7 @@ int mt_set_default_dram_perf(int nid, struct access_coordinate *perf, > > { > > int rc = 0; > > > > - mutex_lock(&memory_tier_lock); > > + mutex_lock(&default_dram_perf_lock); > > if (default_dram_perf_error) { > > rc = -EIO; > > goto out; > > @@ -716,23 +761,30 @@ int mt_set_default_dram_perf(int nid, struct access_coordinate *perf, > > } > > > > out: > > - mutex_unlock(&memory_tier_lock); > > + mutex_unlock(&default_dram_perf_lock); > > return rc; > > } > > > > int mt_perf_to_adistance(struct access_coordinate *perf, int *adist) > > { > > - if (default_dram_perf_error) > > - return -EIO; > > + int rc = 0; > > > > - if (default_dram_perf_ref_nid == NUMA_NO_NODE) > > - return -ENOENT; > > + mutex_lock(&default_dram_perf_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) > > - return -EINVAL; > > + perf->read_bandwidth + perf->write_bandwidth == 0) { > > + rc = -EINVAL; > > + goto out; > > + } > > > > - mutex_lock(&memory_tier_lock); > > + if (default_dram_perf_ref_nid == NUMA_NO_NODE) { > > + rc = -ENOENT; > > + goto out; > > + } > > /* > > * The abstract distance of a memory node is in direct proportion to > > * its memory latency (read + write) and inversely proportional to its > > @@ -745,8 +797,9 @@ int mt_perf_to_adistance(struct access_coordinate *perf, int *adist) > > (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); > > > > +out: > > + mutex_unlock(&default_dram_perf_lock); > > return 0; > > } > > EXPORT_SYMBOL_GPL(mt_perf_to_adistance); > > @@ -858,7 +911,8 @@ static int __init memory_tier_init(void) > > * For now we can have 4 faster memory tiers with smaller adistance > > * than default DRAM tier. > > */ > > - default_dram_type = alloc_memory_type(MEMTIER_ADISTANCE_DRAM); > > + default_dram_type = mt_find_alloc_memory_type(MEMTIER_ADISTANCE_DRAM, > > + &default_memory_types); > > if (IS_ERR(default_dram_type)) > > panic("%s() failed to allocate default DRAM tier\n", __func__); > > > > @@ -868,6 +922,14 @@ static int __init memory_tier_init(void) > > * types assigned. > > */ > > for_each_node_state(node, N_MEMORY) { > > + if (!node_state(node, N_CPU)) > > + /* > > + * Defer memory tier initialization on CPUless numa nodes. > > + * These will be initialized after firmware and devices are > > + * initialized. > > + */ > > + continue; > > + > > memtier = set_node_memory_tier(node); > > if (IS_ERR(memtier)) > > /* > > -- > Best Regards, > Huang, Ying
diff --git a/mm/memory-tiers.c b/mm/memory-tiers.c index 974af10cfdd8..e24fc3bebae4 100644 --- a/mm/memory-tiers.c +++ b/mm/memory-tiers.c @@ -36,6 +36,11 @@ struct node_memory_type_map { static DEFINE_MUTEX(memory_tier_lock); static LIST_HEAD(memory_tiers); +/* + * The list is used to store all memory types that are not created + * by a device driver. + */ +static LIST_HEAD(default_memory_types); static struct node_memory_type_map node_memory_types[MAX_NUMNODES]; struct memory_dev_type *default_dram_type; @@ -108,6 +113,8 @@ static struct demotion_nodes *node_demotion __read_mostly; static BLOCKING_NOTIFIER_HEAD(mt_adistance_algorithms); +/* The lock is used to protect `default_dram_perf*` info and nid. */ +static DEFINE_MUTEX(default_dram_perf_lock); static bool default_dram_perf_error; static struct access_coordinate default_dram_perf; static int default_dram_perf_ref_nid = NUMA_NO_NODE; @@ -505,7 +512,8 @@ static inline void __init_node_memory_type(int node, struct memory_dev_type *mem static struct memory_tier *set_node_memory_tier(int node) { struct memory_tier *memtier; - struct memory_dev_type *memtype; + struct memory_dev_type *mtype = default_dram_type; + int adist = MEMTIER_ADISTANCE_DRAM; pg_data_t *pgdat = NODE_DATA(node); @@ -514,11 +522,20 @@ static struct memory_tier *set_node_memory_tier(int node) if (!node_state(node, N_MEMORY)) return ERR_PTR(-EINVAL); - __init_node_memory_type(node, default_dram_type); + mt_calc_adistance(node, &adist); + if (node_memory_types[node].memtype == NULL) { + mtype = mt_find_alloc_memory_type(adist, &default_memory_types); + if (IS_ERR(mtype)) { + mtype = default_dram_type; + pr_info("Failed to allocate a memory type. Fall back.\n"); + } + } + + __init_node_memory_type(node, mtype); - memtype = node_memory_types[node].memtype; - node_set(node, memtype->nodes); - memtier = find_create_memory_tier(memtype); + mtype = node_memory_types[node].memtype; + node_set(node, mtype->nodes); + memtier = find_create_memory_tier(mtype); if (!IS_ERR(memtier)) rcu_assign_pointer(pgdat->memtier, memtier); return memtier; @@ -655,6 +672,34 @@ void mt_put_memory_types(struct list_head *memory_types) } EXPORT_SYMBOL_GPL(mt_put_memory_types); +/* + * This is invoked via `late_initcall()` to initialize memory tiers for + * CPU-less memory nodes after driver initialization, which is + * expected to provide `adistance` algorithms. + */ +static int __init memory_tier_late_init(void) +{ + int nid; + + mutex_lock(&memory_tier_lock); + for_each_node_state(nid, N_MEMORY) + if (!node_state(nid, N_CPU) && + node_memory_types[nid].memtype == NULL) + /* + * Some device drivers may have initialized memory tiers + * between `memory_tier_init()` and `memory_tier_late_init()`, + * potentially bringing online memory nodes and + * configuring memory tiers. Exclude them here. + */ + set_node_memory_tier(nid); + + establish_demotion_targets(); + mutex_unlock(&memory_tier_lock); + + return 0; +} +late_initcall(memory_tier_late_init); + static void dump_hmem_attrs(struct access_coordinate *coord, const char *prefix) { pr_info( @@ -668,7 +713,7 @@ int mt_set_default_dram_perf(int nid, struct access_coordinate *perf, { int rc = 0; - mutex_lock(&memory_tier_lock); + mutex_lock(&default_dram_perf_lock); if (default_dram_perf_error) { rc = -EIO; goto out; @@ -716,23 +761,30 @@ int mt_set_default_dram_perf(int nid, struct access_coordinate *perf, } out: - mutex_unlock(&memory_tier_lock); + mutex_unlock(&default_dram_perf_lock); return rc; } int mt_perf_to_adistance(struct access_coordinate *perf, int *adist) { - if (default_dram_perf_error) - return -EIO; + int rc = 0; - if (default_dram_perf_ref_nid == NUMA_NO_NODE) - return -ENOENT; + mutex_lock(&default_dram_perf_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) - return -EINVAL; + perf->read_bandwidth + perf->write_bandwidth == 0) { + rc = -EINVAL; + goto out; + } - mutex_lock(&memory_tier_lock); + if (default_dram_perf_ref_nid == NUMA_NO_NODE) { + rc = -ENOENT; + goto out; + } /* * The abstract distance of a memory node is in direct proportion to * its memory latency (read + write) and inversely proportional to its @@ -745,8 +797,9 @@ int mt_perf_to_adistance(struct access_coordinate *perf, int *adist) (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); +out: + mutex_unlock(&default_dram_perf_lock); return 0; } EXPORT_SYMBOL_GPL(mt_perf_to_adistance); @@ -858,7 +911,8 @@ static int __init memory_tier_init(void) * For now we can have 4 faster memory tiers with smaller adistance * than default DRAM tier. */ - default_dram_type = alloc_memory_type(MEMTIER_ADISTANCE_DRAM); + default_dram_type = mt_find_alloc_memory_type(MEMTIER_ADISTANCE_DRAM, + &default_memory_types); if (IS_ERR(default_dram_type)) panic("%s() failed to allocate default DRAM tier\n", __func__); @@ -868,6 +922,14 @@ static int __init memory_tier_init(void) * types assigned. */ for_each_node_state(node, N_MEMORY) { + if (!node_state(node, N_CPU)) + /* + * Defer memory tier initialization on CPUless numa nodes. + * These will be initialized after firmware and devices are + * initialized. + */ + continue; + memtier = set_node_memory_tier(node); if (IS_ERR(memtier)) /*