diff options
Diffstat (limited to 'mm/mempolicy.c')
| -rw-r--r-- | mm/mempolicy.c | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/mm/mempolicy.c b/mm/mempolicy.c index eb83cff7db8c..7ae3f5e2dee6 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -85,6 +85,7 @@ #include <linux/sched.h> #include <linux/sched/mm.h> #include <linux/sched/numa_balancing.h> +#include <linux/sched/sysctl.h> #include <linux/sched/task.h> #include <linux/nodemask.h> #include <linux/cpuset.h> @@ -99,6 +100,7 @@ #include <linux/swap.h> #include <linux/seq_file.h> #include <linux/proc_fs.h> +#include <linux/memory-tiers.h> #include <linux/migrate.h> #include <linux/ksm.h> #include <linux/rmap.h> @@ -803,6 +805,65 @@ unlock: } #ifdef CONFIG_NUMA_BALANCING +/** + * folio_can_map_prot_numa() - check whether the folio can map prot numa + * @folio: The folio whose mapping considered for being made NUMA hintable + * @vma: The VMA that the folio belongs to. + * @is_private_single_threaded: Is this a single-threaded private VMA or not + * + * This function checks to see if the folio actually indicates that + * we need to make the mapping one which causes a NUMA hinting fault, + * as there are cases where it's simply unnecessary, and the folio's + * access time is adjusted for memory tiering if prot numa needed. + * + * Return: True if the mapping of the folio needs to be changed, false otherwise. + */ +bool folio_can_map_prot_numa(struct folio *folio, struct vm_area_struct *vma, + bool is_private_single_threaded) +{ + int nid; + + if (!folio || folio_is_zone_device(folio) || folio_test_ksm(folio)) + return false; + + /* Also skip shared copy-on-write folios */ + if (is_cow_mapping(vma->vm_flags) && folio_maybe_mapped_shared(folio)) + return false; + + /* Folios are pinned and can't be migrated */ + if (folio_maybe_dma_pinned(folio)) + return false; + + /* + * While migration can move some dirty folios, + * it cannot move them all from MIGRATE_ASYNC + * context. + */ + if (folio_is_file_lru(folio) && folio_test_dirty(folio)) + return false; + + /* + * Don't mess with PTEs if folio is already on the node + * a single-threaded process is running on. + */ + nid = folio_nid(folio); + if (is_private_single_threaded && (nid == numa_node_id())) + return false; + + /* + * Skip scanning top tier node if normal numa + * balancing is disabled + */ + if (!(sysctl_numa_balancing_mode & NUMA_BALANCING_NORMAL) && + node_is_toptier(nid)) + return false; + + if (folio_use_access_time(folio)) + folio_xchg_access_time(folio, jiffies_to_msecs(jiffies)); + + return true; +} + /* * This is used to mark a range of virtual addresses to be inaccessible. * These are later cleared by a NUMA hinting fault. Depending on these |