diff mbox series

[v11,8/8] mm/demotion: Update node_is_toptier to work with memory tiers

Message ID 20220728190436.858458-9-aneesh.kumar@linux.ibm.com (mailing list archive)
State New
Headers show
Series mm/demotion: Memory tiers and demotion | expand

Commit Message

Aneesh Kumar K.V July 28, 2022, 7:04 p.m. UTC
With memory tiers support we can have memory only NUMA nodes
in the top tier from which we want to avoid promotion tracking NUMA
faults. Update node_is_toptier to work with memory tiers.
All NUMA nodes are by default top tier nodes. With lower memory
tiers added we consider all memory tiers above a memory tier having
CPU NUMA nodes as a top memory tier

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
 include/linux/memory-tiers.h | 11 ++++++++++
 include/linux/node.h         |  5 -----
 mm/huge_memory.c             |  1 +
 mm/memory-tiers.c            | 42 ++++++++++++++++++++++++++++++++++++
 mm/migrate.c                 |  1 +
 mm/mprotect.c                |  1 +
 6 files changed, 56 insertions(+), 5 deletions(-)

Comments

Huang, Ying July 29, 2022, 6:39 a.m. UTC | #1
"Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> writes:

> With memory tiers support we can have memory only NUMA nodes
> in the top tier from which we want to avoid promotion tracking NUMA
> faults. Update node_is_toptier to work with memory tiers.
> All NUMA nodes are by default top tier nodes. With lower memory
> tiers added we consider all memory tiers above a memory tier having
> CPU NUMA nodes as a top memory tier
>
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
> ---
>  include/linux/memory-tiers.h | 11 ++++++++++
>  include/linux/node.h         |  5 -----
>  mm/huge_memory.c             |  1 +
>  mm/memory-tiers.c            | 42 ++++++++++++++++++++++++++++++++++++
>  mm/migrate.c                 |  1 +
>  mm/mprotect.c                |  1 +
>  6 files changed, 56 insertions(+), 5 deletions(-)
>
> diff --git a/include/linux/memory-tiers.h b/include/linux/memory-tiers.h
> index f8dbeda617a7..bc9fb9d39b2c 100644
> --- a/include/linux/memory-tiers.h
> +++ b/include/linux/memory-tiers.h
> @@ -35,6 +35,7 @@ struct memory_dev_type *init_node_memory_type(int node, struct memory_dev_type *
>  #ifdef CONFIG_MIGRATION
>  int next_demotion_node(int node);
>  void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets);
> +bool node_is_toptier(int node);
>  #else
>  static inline int next_demotion_node(int node)
>  {
> @@ -45,6 +46,11 @@ static inline void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *target
>  {
>  	*targets = NODE_MASK_NONE;
>  }
> +
> +static inline bool node_is_toptier(int node)
> +{
> +	return true;
> +}
>  #endif
>  
>  #else
> @@ -64,5 +70,10 @@ static inline void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *target
>  {
>  	*targets = NODE_MASK_NONE;
>  }
> +
> +static inline bool node_is_toptier(int node)
> +{
> +	return true;
> +}
>  #endif	/* CONFIG_NUMA */
>  #endif  /* _LINUX_MEMORY_TIERS_H */
> diff --git a/include/linux/node.h b/include/linux/node.h
> index 40d641a8bfb0..9ec680dd607f 100644
> --- a/include/linux/node.h
> +++ b/include/linux/node.h
> @@ -185,9 +185,4 @@ static inline void register_hugetlbfs_with_node(node_registration_func_t reg,
>  
>  #define to_node(device) container_of(device, struct node, dev)
>  
> -static inline bool node_is_toptier(int node)
> -{
> -	return node_state(node, N_CPU);
> -}
> -
>  #endif /* _LINUX_NODE_H_ */
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index 834f288b3769..8405662646e9 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -35,6 +35,7 @@
>  #include <linux/numa.h>
>  #include <linux/page_owner.h>
>  #include <linux/sched/sysctl.h>
> +#include <linux/memory-tiers.h>
>  
>  #include <asm/tlb.h>
>  #include <asm/pgalloc.h>
> diff --git a/mm/memory-tiers.c b/mm/memory-tiers.c
> index 84e2be31a853..36d87dc422ab 100644
> --- a/mm/memory-tiers.c
> +++ b/mm/memory-tiers.c
> @@ -30,6 +30,7 @@ static DEFINE_MUTEX(memory_tier_lock);
>  static LIST_HEAD(memory_tiers);
>  struct memory_dev_type *node_memory_types[MAX_NUMNODES];
>  #ifdef CONFIG_MIGRATION
> +static int top_tier_adistance;
>  /*
>   * node_demotion[] examples:
>   *
> @@ -159,6 +160,31 @@ static struct memory_tier *__node_get_memory_tier(int node)
>  }
>  
>  #ifdef CONFIG_MIGRATION
> +bool node_is_toptier(int node)
> +{
> +	bool toptier;
> +	pg_data_t *pgdat;
> +	struct memory_tier *memtier;
> +
> +	pgdat = NODE_DATA(node);
> +	if (!pgdat)
> +		return false;
> +
> +	rcu_read_lock();
> +	memtier = rcu_dereference(pgdat->memtier);
> +	if (!memtier) {
> +		toptier = true;
> +		goto out;
> +	}
> +	if (memtier->adistance_start >= top_tier_adistance)
> +		toptier = true;
> +	else
> +		toptier = false;
> +out:
> +	rcu_read_unlock();
> +	return toptier;
> +}
> +
>  void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets)
>  {
>  	struct memory_tier *memtier;
> @@ -315,6 +341,22 @@ static void establish_demotion_targets(void)
>  			}
>  		} while (1);
>  	}
> +	/*
> +	 * Promotion is allowed from a memory tier to higher
> +	 * memory tier only if the memory tier doesn't include
> +	 * compute. We want to  skip promotion from a memory tier,
> +	 * if any node that is  part of the memory tier have CPUs.
> +	 * Once we detect such a memory tier, we consider that tier
> +	 * as top tiper from which promotion on is not allowed.
> +	 */
> +	list_for_each_entry(memtier, &memory_tiers, list) {
> +		tier_nodes = get_memtier_nodemask(memtier);
> +		nodes_and(tier_nodes, node_states[N_CPU], tier_nodes);
> +		if (!nodes_empty(tier_nodes)) {
> +			top_tier_adistance = memtier->adistance_start;

IMHO, this should be,

			top_tier_adistance = memtier->adistance_start + MEMTIER_CHUNK_SIZE;

Best Regards,
Huang, Ying

> +			break;
> +		}
> +	}
>  	/*
>  	 * Now build the lower_tier mask for each node collecting node mask from
>  	 * all memory tier below it. This allows us to fallback demotion page
> diff --git a/mm/migrate.c b/mm/migrate.c
> index c758c9c21d7d..1da81136eaaa 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -50,6 +50,7 @@
>  #include <linux/memory.h>
>  #include <linux/random.h>
>  #include <linux/sched/sysctl.h>
> +#include <linux/memory-tiers.h>
>  
>  #include <asm/tlbflush.h>
>  
> diff --git a/mm/mprotect.c b/mm/mprotect.c
> index ba5592655ee3..92a2fc0fa88b 100644
> --- a/mm/mprotect.c
> +++ b/mm/mprotect.c
> @@ -31,6 +31,7 @@
>  #include <linux/pgtable.h>
>  #include <linux/sched/sysctl.h>
>  #include <linux/userfaultfd_k.h>
> +#include <linux/memory-tiers.h>
>  #include <asm/cacheflush.h>
>  #include <asm/mmu_context.h>
>  #include <asm/tlbflush.h>
Aneesh Kumar K.V July 29, 2022, 6:41 a.m. UTC | #2
On 7/29/22 12:09 PM, Huang, Ying wrote:
> "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> writes:
> 
>> With memory tiers support we can have memory only NUMA nodes
>> in the top tier from which we want to avoid promotion tracking NUMA
>> faults. Update node_is_toptier to work with memory tiers.
>> All NUMA nodes are by default top tier nodes. With lower memory
>> tiers added we consider all memory tiers above a memory tier having
>> CPU NUMA nodes as a top memory tier
>>
>> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
>> ---
>>  include/linux/memory-tiers.h | 11 ++++++++++
>>  include/linux/node.h         |  5 -----
>>  mm/huge_memory.c             |  1 +
>>  mm/memory-tiers.c            | 42 ++++++++++++++++++++++++++++++++++++
>>  mm/migrate.c                 |  1 +
>>  mm/mprotect.c                |  1 +
>>  6 files changed, 56 insertions(+), 5 deletions(-)
>>
>> diff --git a/include/linux/memory-tiers.h b/include/linux/memory-tiers.h
>> index f8dbeda617a7..bc9fb9d39b2c 100644
>> --- a/include/linux/memory-tiers.h
>> +++ b/include/linux/memory-tiers.h
>> @@ -35,6 +35,7 @@ struct memory_dev_type *init_node_memory_type(int node, struct memory_dev_type *
>>  #ifdef CONFIG_MIGRATION
>>  int next_demotion_node(int node);
>>  void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets);
>> +bool node_is_toptier(int node);
>>  #else
>>  static inline int next_demotion_node(int node)
>>  {
>> @@ -45,6 +46,11 @@ static inline void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *target
>>  {
>>  	*targets = NODE_MASK_NONE;
>>  }
>> +
>> +static inline bool node_is_toptier(int node)
>> +{
>> +	return true;
>> +}
>>  #endif
>>  
>>  #else
>> @@ -64,5 +70,10 @@ static inline void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *target
>>  {
>>  	*targets = NODE_MASK_NONE;
>>  }
>> +
>> +static inline bool node_is_toptier(int node)
>> +{
>> +	return true;
>> +}
>>  #endif	/* CONFIG_NUMA */
>>  #endif  /* _LINUX_MEMORY_TIERS_H */
>> diff --git a/include/linux/node.h b/include/linux/node.h
>> index 40d641a8bfb0..9ec680dd607f 100644
>> --- a/include/linux/node.h
>> +++ b/include/linux/node.h
>> @@ -185,9 +185,4 @@ static inline void register_hugetlbfs_with_node(node_registration_func_t reg,
>>  
>>  #define to_node(device) container_of(device, struct node, dev)
>>  
>> -static inline bool node_is_toptier(int node)
>> -{
>> -	return node_state(node, N_CPU);
>> -}
>> -
>>  #endif /* _LINUX_NODE_H_ */
>> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
>> index 834f288b3769..8405662646e9 100644
>> --- a/mm/huge_memory.c
>> +++ b/mm/huge_memory.c
>> @@ -35,6 +35,7 @@
>>  #include <linux/numa.h>
>>  #include <linux/page_owner.h>
>>  #include <linux/sched/sysctl.h>
>> +#include <linux/memory-tiers.h>
>>  
>>  #include <asm/tlb.h>
>>  #include <asm/pgalloc.h>
>> diff --git a/mm/memory-tiers.c b/mm/memory-tiers.c
>> index 84e2be31a853..36d87dc422ab 100644
>> --- a/mm/memory-tiers.c
>> +++ b/mm/memory-tiers.c
>> @@ -30,6 +30,7 @@ static DEFINE_MUTEX(memory_tier_lock);
>>  static LIST_HEAD(memory_tiers);
>>  struct memory_dev_type *node_memory_types[MAX_NUMNODES];
>>  #ifdef CONFIG_MIGRATION
>> +static int top_tier_adistance;
>>  /*
>>   * node_demotion[] examples:
>>   *
>> @@ -159,6 +160,31 @@ static struct memory_tier *__node_get_memory_tier(int node)
>>  }
>>  
>>  #ifdef CONFIG_MIGRATION
>> +bool node_is_toptier(int node)
>> +{
>> +	bool toptier;
>> +	pg_data_t *pgdat;
>> +	struct memory_tier *memtier;
>> +
>> +	pgdat = NODE_DATA(node);
>> +	if (!pgdat)
>> +		return false;
>> +
>> +	rcu_read_lock();
>> +	memtier = rcu_dereference(pgdat->memtier);
>> +	if (!memtier) {
>> +		toptier = true;
>> +		goto out;
>> +	}
>> +	if (memtier->adistance_start >= top_tier_adistance)
>> +		toptier = true;
>> +	else
>> +		toptier = false;
>> +out:
>> +	rcu_read_unlock();
>> +	return toptier;
>> +}
>> +
>>  void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets)
>>  {
>>  	struct memory_tier *memtier;
>> @@ -315,6 +341,22 @@ static void establish_demotion_targets(void)
>>  			}
>>  		} while (1);
>>  	}
>> +	/*
>> +	 * Promotion is allowed from a memory tier to higher
>> +	 * memory tier only if the memory tier doesn't include
>> +	 * compute. We want to  skip promotion from a memory tier,
>> +	 * if any node that is  part of the memory tier have CPUs.
>> +	 * Once we detect such a memory tier, we consider that tier
>> +	 * as top tiper from which promotion on is not allowed.
>> +	 */
>> +	list_for_each_entry(memtier, &memory_tiers, list) {
>> +		tier_nodes = get_memtier_nodemask(memtier);
>> +		nodes_and(tier_nodes, node_states[N_CPU], tier_nodes);
>> +		if (!nodes_empty(tier_nodes)) {
>> +			top_tier_adistance = memtier->adistance_start;
> 
> IMHO, this should be,
> 
> 			top_tier_adistance = memtier->adistance_start + MEMTIER_CHUNK_SIZE;
> 

Good catch. Will update. BTW i did send v12 version of the patchset already to the list. 

-aneesh
Aneesh Kumar K.V July 29, 2022, 6:47 a.m. UTC | #3
On 7/29/22 12:11 PM, Aneesh Kumar K V wrote:
> On 7/29/22 12:09 PM, Huang, Ying wrote:
>> "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> writes:
>>
>>> With memory tiers support we can have memory only NUMA nodes
>>> in the top tier from which we want to avoid promotion tracking NUMA
>>> faults. Update node_is_toptier to work with memory tiers.
>>> All NUMA nodes are by default top tier nodes. With lower memory
>>> tiers added we consider all memory tiers above a memory tier having
>>> CPU NUMA nodes as a top memory tier
>>>
>>> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
>>> ---
>>>  include/linux/memory-tiers.h | 11 ++++++++++
>>>  include/linux/node.h         |  5 -----
>>>  mm/huge_memory.c             |  1 +
>>>  mm/memory-tiers.c            | 42 ++++++++++++++++++++++++++++++++++++
>>>  mm/migrate.c                 |  1 +
>>>  mm/mprotect.c                |  1 +
>>>  6 files changed, 56 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/include/linux/memory-tiers.h b/include/linux/memory-tiers.h
>>> index f8dbeda617a7..bc9fb9d39b2c 100644
>>> --- a/include/linux/memory-tiers.h
>>> +++ b/include/linux/memory-tiers.h
>>> @@ -35,6 +35,7 @@ struct memory_dev_type *init_node_memory_type(int node, struct memory_dev_type *
>>>  #ifdef CONFIG_MIGRATION
>>>  int next_demotion_node(int node);
>>>  void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets);
>>> +bool node_is_toptier(int node);
>>>  #else
>>>  static inline int next_demotion_node(int node)
>>>  {
>>> @@ -45,6 +46,11 @@ static inline void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *target
>>>  {
>>>  	*targets = NODE_MASK_NONE;
>>>  }
>>> +
>>> +static inline bool node_is_toptier(int node)
>>> +{
>>> +	return true;
>>> +}
>>>  #endif
>>>  
>>>  #else
>>> @@ -64,5 +70,10 @@ static inline void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *target
>>>  {
>>>  	*targets = NODE_MASK_NONE;
>>>  }
>>> +
>>> +static inline bool node_is_toptier(int node)
>>> +{
>>> +	return true;
>>> +}
>>>  #endif	/* CONFIG_NUMA */
>>>  #endif  /* _LINUX_MEMORY_TIERS_H */
>>> diff --git a/include/linux/node.h b/include/linux/node.h
>>> index 40d641a8bfb0..9ec680dd607f 100644
>>> --- a/include/linux/node.h
>>> +++ b/include/linux/node.h
>>> @@ -185,9 +185,4 @@ static inline void register_hugetlbfs_with_node(node_registration_func_t reg,
>>>  
>>>  #define to_node(device) container_of(device, struct node, dev)
>>>  
>>> -static inline bool node_is_toptier(int node)
>>> -{
>>> -	return node_state(node, N_CPU);
>>> -}
>>> -
>>>  #endif /* _LINUX_NODE_H_ */
>>> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
>>> index 834f288b3769..8405662646e9 100644
>>> --- a/mm/huge_memory.c
>>> +++ b/mm/huge_memory.c
>>> @@ -35,6 +35,7 @@
>>>  #include <linux/numa.h>
>>>  #include <linux/page_owner.h>
>>>  #include <linux/sched/sysctl.h>
>>> +#include <linux/memory-tiers.h>
>>>  
>>>  #include <asm/tlb.h>
>>>  #include <asm/pgalloc.h>
>>> diff --git a/mm/memory-tiers.c b/mm/memory-tiers.c
>>> index 84e2be31a853..36d87dc422ab 100644
>>> --- a/mm/memory-tiers.c
>>> +++ b/mm/memory-tiers.c
>>> @@ -30,6 +30,7 @@ static DEFINE_MUTEX(memory_tier_lock);
>>>  static LIST_HEAD(memory_tiers);
>>>  struct memory_dev_type *node_memory_types[MAX_NUMNODES];
>>>  #ifdef CONFIG_MIGRATION
>>> +static int top_tier_adistance;
>>>  /*
>>>   * node_demotion[] examples:
>>>   *
>>> @@ -159,6 +160,31 @@ static struct memory_tier *__node_get_memory_tier(int node)
>>>  }
>>>  
>>>  #ifdef CONFIG_MIGRATION
>>> +bool node_is_toptier(int node)
>>> +{
>>> +	bool toptier;
>>> +	pg_data_t *pgdat;
>>> +	struct memory_tier *memtier;
>>> +
>>> +	pgdat = NODE_DATA(node);
>>> +	if (!pgdat)
>>> +		return false;
>>> +
>>> +	rcu_read_lock();
>>> +	memtier = rcu_dereference(pgdat->memtier);
>>> +	if (!memtier) {
>>> +		toptier = true;
>>> +		goto out;
>>> +	}
>>> +	if (memtier->adistance_start >= top_tier_adistance)
>>> +		toptier = true;
>>> +	else
>>> +		toptier = false;
>>> +out:
>>> +	rcu_read_unlock();
>>> +	return toptier;
>>> +}
>>> +
>>>  void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets)
>>>  {
>>>  	struct memory_tier *memtier;
>>> @@ -315,6 +341,22 @@ static void establish_demotion_targets(void)
>>>  			}
>>>  		} while (1);
>>>  	}
>>> +	/*
>>> +	 * Promotion is allowed from a memory tier to higher
>>> +	 * memory tier only if the memory tier doesn't include
>>> +	 * compute. We want to  skip promotion from a memory tier,
>>> +	 * if any node that is  part of the memory tier have CPUs.
>>> +	 * Once we detect such a memory tier, we consider that tier
>>> +	 * as top tiper from which promotion on is not allowed.
>>> +	 */
>>> +	list_for_each_entry(memtier, &memory_tiers, list) {
>>> +		tier_nodes = get_memtier_nodemask(memtier);
>>> +		nodes_and(tier_nodes, node_states[N_CPU], tier_nodes);
>>> +		if (!nodes_empty(tier_nodes)) {
>>> +			top_tier_adistance = memtier->adistance_start;
>>
>> IMHO, this should be,
>>
>> 			top_tier_adistance = memtier->adistance_start + MEMTIER_CHUNK_SIZE;
>>
> 
> Good catch. Will update. BTW i did send v12 version of the patchset already to the list. 
> 
>

Checking this again, we consider a node top tier if the node's memtier abstract distance
satisfy the below.  

	if (memtier->adistance_start <= top_tier_adistance)
		toptier = true;
	
With that we should be good with the current code. But I agree with you that top_tier_distance
should cover the full range of the top memory tier.

-aneesh
Huang, Ying Aug. 1, 2022, 1:04 a.m. UTC | #4
Aneesh Kumar K V <aneesh.kumar@linux.ibm.com> writes:

> On 7/29/22 12:11 PM, Aneesh Kumar K V wrote:
>> On 7/29/22 12:09 PM, Huang, Ying wrote:
>>> "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> writes:
>>>
>>>> With memory tiers support we can have memory only NUMA nodes
>>>> in the top tier from which we want to avoid promotion tracking NUMA
>>>> faults. Update node_is_toptier to work with memory tiers.
>>>> All NUMA nodes are by default top tier nodes. With lower memory
>>>> tiers added we consider all memory tiers above a memory tier having
>>>> CPU NUMA nodes as a top memory tier
>>>>
>>>> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
>>>> ---
>>>>  include/linux/memory-tiers.h | 11 ++++++++++
>>>>  include/linux/node.h         |  5 -----
>>>>  mm/huge_memory.c             |  1 +
>>>>  mm/memory-tiers.c            | 42 ++++++++++++++++++++++++++++++++++++
>>>>  mm/migrate.c                 |  1 +
>>>>  mm/mprotect.c                |  1 +
>>>>  6 files changed, 56 insertions(+), 5 deletions(-)
>>>>
>>>> diff --git a/include/linux/memory-tiers.h b/include/linux/memory-tiers.h
>>>> index f8dbeda617a7..bc9fb9d39b2c 100644
>>>> --- a/include/linux/memory-tiers.h
>>>> +++ b/include/linux/memory-tiers.h
>>>> @@ -35,6 +35,7 @@ struct memory_dev_type *init_node_memory_type(int node, struct memory_dev_type *
>>>>  #ifdef CONFIG_MIGRATION
>>>>  int next_demotion_node(int node);
>>>>  void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets);
>>>> +bool node_is_toptier(int node);
>>>>  #else
>>>>  static inline int next_demotion_node(int node)
>>>>  {
>>>> @@ -45,6 +46,11 @@ static inline void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *target
>>>>  {
>>>>  	*targets = NODE_MASK_NONE;
>>>>  }
>>>> +
>>>> +static inline bool node_is_toptier(int node)
>>>> +{
>>>> +	return true;
>>>> +}
>>>>  #endif
>>>>  
>>>>  #else
>>>> @@ -64,5 +70,10 @@ static inline void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *target
>>>>  {
>>>>  	*targets = NODE_MASK_NONE;
>>>>  }
>>>> +
>>>> +static inline bool node_is_toptier(int node)
>>>> +{
>>>> +	return true;
>>>> +}
>>>>  #endif	/* CONFIG_NUMA */
>>>>  #endif  /* _LINUX_MEMORY_TIERS_H */
>>>> diff --git a/include/linux/node.h b/include/linux/node.h
>>>> index 40d641a8bfb0..9ec680dd607f 100644
>>>> --- a/include/linux/node.h
>>>> +++ b/include/linux/node.h
>>>> @@ -185,9 +185,4 @@ static inline void register_hugetlbfs_with_node(node_registration_func_t reg,
>>>>  
>>>>  #define to_node(device) container_of(device, struct node, dev)
>>>>  
>>>> -static inline bool node_is_toptier(int node)
>>>> -{
>>>> -	return node_state(node, N_CPU);
>>>> -}
>>>> -
>>>>  #endif /* _LINUX_NODE_H_ */
>>>> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
>>>> index 834f288b3769..8405662646e9 100644
>>>> --- a/mm/huge_memory.c
>>>> +++ b/mm/huge_memory.c
>>>> @@ -35,6 +35,7 @@
>>>>  #include <linux/numa.h>
>>>>  #include <linux/page_owner.h>
>>>>  #include <linux/sched/sysctl.h>
>>>> +#include <linux/memory-tiers.h>
>>>>  
>>>>  #include <asm/tlb.h>
>>>>  #include <asm/pgalloc.h>
>>>> diff --git a/mm/memory-tiers.c b/mm/memory-tiers.c
>>>> index 84e2be31a853..36d87dc422ab 100644
>>>> --- a/mm/memory-tiers.c
>>>> +++ b/mm/memory-tiers.c
>>>> @@ -30,6 +30,7 @@ static DEFINE_MUTEX(memory_tier_lock);
>>>>  static LIST_HEAD(memory_tiers);
>>>>  struct memory_dev_type *node_memory_types[MAX_NUMNODES];
>>>>  #ifdef CONFIG_MIGRATION
>>>> +static int top_tier_adistance;
>>>>  /*
>>>>   * node_demotion[] examples:
>>>>   *
>>>> @@ -159,6 +160,31 @@ static struct memory_tier *__node_get_memory_tier(int node)
>>>>  }
>>>>  
>>>>  #ifdef CONFIG_MIGRATION
>>>> +bool node_is_toptier(int node)
>>>> +{
>>>> +	bool toptier;
>>>> +	pg_data_t *pgdat;
>>>> +	struct memory_tier *memtier;
>>>> +
>>>> +	pgdat = NODE_DATA(node);
>>>> +	if (!pgdat)
>>>> +		return false;
>>>> +
>>>> +	rcu_read_lock();
>>>> +	memtier = rcu_dereference(pgdat->memtier);
>>>> +	if (!memtier) {
>>>> +		toptier = true;
>>>> +		goto out;
>>>> +	}
>>>> +	if (memtier->adistance_start >= top_tier_adistance)
>>>> +		toptier = true;
>>>> +	else
>>>> +		toptier = false;
>>>> +out:
>>>> +	rcu_read_unlock();
>>>> +	return toptier;
>>>> +}
>>>> +
>>>>  void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets)
>>>>  {
>>>>  	struct memory_tier *memtier;
>>>> @@ -315,6 +341,22 @@ static void establish_demotion_targets(void)
>>>>  			}
>>>>  		} while (1);
>>>>  	}
>>>> +	/*
>>>> +	 * Promotion is allowed from a memory tier to higher
>>>> +	 * memory tier only if the memory tier doesn't include
>>>> +	 * compute. We want to  skip promotion from a memory tier,
>>>> +	 * if any node that is  part of the memory tier have CPUs.
>>>> +	 * Once we detect such a memory tier, we consider that tier
>>>> +	 * as top tiper from which promotion on is not allowed.
>>>> +	 */
>>>> +	list_for_each_entry(memtier, &memory_tiers, list) {
>>>> +		tier_nodes = get_memtier_nodemask(memtier);
>>>> +		nodes_and(tier_nodes, node_states[N_CPU], tier_nodes);
>>>> +		if (!nodes_empty(tier_nodes)) {
>>>> +			top_tier_adistance = memtier->adistance_start;
>>>
>>> IMHO, this should be,
>>>
>>> 			top_tier_adistance = memtier->adistance_start + MEMTIER_CHUNK_SIZE;
>>>
>> 
>> Good catch. Will update. BTW i did send v12 version of the patchset already to the list. 
>> 
>>
>
> Checking this again, we consider a node top tier if the node's memtier abstract distance
> satisfy the below.  
>
> 	if (memtier->adistance_start <= top_tier_adistance)
> 		toptier = true;

I admit that this works correctly.  And I think that the following code
is even more correct conceptually.  If so, why not help the code reader
to understand it more easily?

        if (memtier->adistance_start + MEMTIER_CHUNK_SIZE <= top_tier_adistance)
                toptier = true;

Best Regards,
Huang, Ying

> With that we should be good with the current code. But I agree with you that top_tier_distance
> should cover the full range of the top memory tier.
>
> -aneesh
diff mbox series

Patch

diff --git a/include/linux/memory-tiers.h b/include/linux/memory-tiers.h
index f8dbeda617a7..bc9fb9d39b2c 100644
--- a/include/linux/memory-tiers.h
+++ b/include/linux/memory-tiers.h
@@ -35,6 +35,7 @@  struct memory_dev_type *init_node_memory_type(int node, struct memory_dev_type *
 #ifdef CONFIG_MIGRATION
 int next_demotion_node(int node);
 void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets);
+bool node_is_toptier(int node);
 #else
 static inline int next_demotion_node(int node)
 {
@@ -45,6 +46,11 @@  static inline void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *target
 {
 	*targets = NODE_MASK_NONE;
 }
+
+static inline bool node_is_toptier(int node)
+{
+	return true;
+}
 #endif
 
 #else
@@ -64,5 +70,10 @@  static inline void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *target
 {
 	*targets = NODE_MASK_NONE;
 }
+
+static inline bool node_is_toptier(int node)
+{
+	return true;
+}
 #endif	/* CONFIG_NUMA */
 #endif  /* _LINUX_MEMORY_TIERS_H */
diff --git a/include/linux/node.h b/include/linux/node.h
index 40d641a8bfb0..9ec680dd607f 100644
--- a/include/linux/node.h
+++ b/include/linux/node.h
@@ -185,9 +185,4 @@  static inline void register_hugetlbfs_with_node(node_registration_func_t reg,
 
 #define to_node(device) container_of(device, struct node, dev)
 
-static inline bool node_is_toptier(int node)
-{
-	return node_state(node, N_CPU);
-}
-
 #endif /* _LINUX_NODE_H_ */
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 834f288b3769..8405662646e9 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -35,6 +35,7 @@ 
 #include <linux/numa.h>
 #include <linux/page_owner.h>
 #include <linux/sched/sysctl.h>
+#include <linux/memory-tiers.h>
 
 #include <asm/tlb.h>
 #include <asm/pgalloc.h>
diff --git a/mm/memory-tiers.c b/mm/memory-tiers.c
index 84e2be31a853..36d87dc422ab 100644
--- a/mm/memory-tiers.c
+++ b/mm/memory-tiers.c
@@ -30,6 +30,7 @@  static DEFINE_MUTEX(memory_tier_lock);
 static LIST_HEAD(memory_tiers);
 struct memory_dev_type *node_memory_types[MAX_NUMNODES];
 #ifdef CONFIG_MIGRATION
+static int top_tier_adistance;
 /*
  * node_demotion[] examples:
  *
@@ -159,6 +160,31 @@  static struct memory_tier *__node_get_memory_tier(int node)
 }
 
 #ifdef CONFIG_MIGRATION
+bool node_is_toptier(int node)
+{
+	bool toptier;
+	pg_data_t *pgdat;
+	struct memory_tier *memtier;
+
+	pgdat = NODE_DATA(node);
+	if (!pgdat)
+		return false;
+
+	rcu_read_lock();
+	memtier = rcu_dereference(pgdat->memtier);
+	if (!memtier) {
+		toptier = true;
+		goto out;
+	}
+	if (memtier->adistance_start >= top_tier_adistance)
+		toptier = true;
+	else
+		toptier = false;
+out:
+	rcu_read_unlock();
+	return toptier;
+}
+
 void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets)
 {
 	struct memory_tier *memtier;
@@ -315,6 +341,22 @@  static void establish_demotion_targets(void)
 			}
 		} while (1);
 	}
+	/*
+	 * Promotion is allowed from a memory tier to higher
+	 * memory tier only if the memory tier doesn't include
+	 * compute. We want to  skip promotion from a memory tier,
+	 * if any node that is  part of the memory tier have CPUs.
+	 * Once we detect such a memory tier, we consider that tier
+	 * as top tiper from which promotion on is not allowed.
+	 */
+	list_for_each_entry(memtier, &memory_tiers, list) {
+		tier_nodes = get_memtier_nodemask(memtier);
+		nodes_and(tier_nodes, node_states[N_CPU], tier_nodes);
+		if (!nodes_empty(tier_nodes)) {
+			top_tier_adistance = memtier->adistance_start;
+			break;
+		}
+	}
 	/*
 	 * Now build the lower_tier mask for each node collecting node mask from
 	 * all memory tier below it. This allows us to fallback demotion page
diff --git a/mm/migrate.c b/mm/migrate.c
index c758c9c21d7d..1da81136eaaa 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -50,6 +50,7 @@ 
 #include <linux/memory.h>
 #include <linux/random.h>
 #include <linux/sched/sysctl.h>
+#include <linux/memory-tiers.h>
 
 #include <asm/tlbflush.h>
 
diff --git a/mm/mprotect.c b/mm/mprotect.c
index ba5592655ee3..92a2fc0fa88b 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -31,6 +31,7 @@ 
 #include <linux/pgtable.h>
 #include <linux/sched/sysctl.h>
 #include <linux/userfaultfd_k.h>
+#include <linux/memory-tiers.h>
 #include <asm/cacheflush.h>
 #include <asm/mmu_context.h>
 #include <asm/tlbflush.h>