From: Bijan Tabatabai Date: Wed, 9 Jul 2025 00:59:41 +0000 (-0500) Subject: mm/damon/vaddr: use damos->migrate_dests in migrate_{hot,cold} X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=19c1dc15c859929f8f084d0bfa2fafd1ee876cdd;p=thirdparty%2Flinux.git mm/damon/vaddr: use damos->migrate_dests in migrate_{hot,cold} damos->migrate_dests provides a list of nodes the migrate_{hot,cold} actions should migrate to, as well as the weights which specify the ratio pages should be migrated to each destination node. This patch interleaves pages in the migrate_{hot,cold} actions according to the information provided in damos->migrate_dests if it is used. The interleaving algorithm used is similar to the one used in weighted_interleave_nid(). If damos->migration_dests is not provided, the actions migrate pages to the node specified in damos->target_nid as before. Link: https://lkml.kernel.org/r/20250709005952.17776-12-bijan311@gmail.com Co-developed-by: Ravi Shankar Jonnalagadda Signed-off-by: Ravi Shankar Jonnalagadda Signed-off-by: Bijan Tabatabai Reviewed-by: SeongJae Park Cc: Jonathan Corbet Signed-off-by: Andrew Morton --- diff --git a/mm/damon/vaddr.c b/mm/damon/vaddr.c index b244ac056416c..47d5f33f89c88 100644 --- a/mm/damon/vaddr.c +++ b/mm/damon/vaddr.c @@ -611,11 +611,69 @@ static unsigned int damon_va_check_accesses(struct damon_ctx *ctx) return max_nr_accesses; } +struct damos_va_migrate_private { + struct list_head *migration_lists; + struct damos_migrate_dests *dests; +}; + +/* + * Place the given folio in the migration_list corresponding to where the folio + * should be migrated. + * + * The algorithm used here is similar to weighted_interleave_nid() + */ +static void damos_va_migrate_dests_add(struct folio *folio, + struct vm_area_struct *vma, unsigned long addr, + struct damos_migrate_dests *dests, + struct list_head *migration_lists) +{ + pgoff_t ilx; + int order; + unsigned int target; + unsigned int weight_total = 0; + int i; + + /* + * If dests is empty, there is only one migration list corresponding + * to s->target_nid. + */ + if (!dests->nr_dests) { + i = 0; + goto isolate; + } + + order = folio_order(folio); + ilx = vma->vm_pgoff >> order; + ilx += (addr - vma->vm_start) >> (PAGE_SHIFT + order); + + for (i = 0; i < dests->nr_dests; i++) + weight_total += dests->weight_arr[i]; + + /* If the total weights are somehow 0, don't migrate at all */ + if (!weight_total) + return; + + target = ilx % weight_total; + for (i = 0; i < dests->nr_dests; i++) { + if (target < dests->weight_arr[i]) + break; + target -= dests->weight_arr[i]; + } + +isolate: + if (!folio_isolate_lru(folio)) + return; + + list_add(&folio->lru, &migration_lists[i]); +} + #ifdef CONFIG_TRANSPARENT_HUGEPAGE static int damos_va_migrate_pmd_entry(pmd_t *pmd, unsigned long addr, unsigned long next, struct mm_walk *walk) { - struct list_head *migration_list = walk->private; + struct damos_va_migrate_private *priv = walk->private; + struct list_head *migration_lists = priv->migration_lists; + struct damos_migrate_dests *dests = priv->dests; struct folio *folio; spinlock_t *ptl; pmd_t pmde; @@ -633,12 +691,9 @@ static int damos_va_migrate_pmd_entry(pmd_t *pmd, unsigned long addr, if (!folio) goto unlock; - if (!folio_isolate_lru(folio)) - goto put_folio; - - list_add(&folio->lru, migration_list); + damos_va_migrate_dests_add(folio, walk->vma, addr, dests, + migration_lists); -put_folio: folio_put(folio); unlock: spin_unlock(ptl); @@ -651,7 +706,9 @@ unlock: static int damos_va_migrate_pte_entry(pte_t *pte, unsigned long addr, unsigned long next, struct mm_walk *walk) { - struct list_head *migration_list = walk->private; + struct damos_va_migrate_private *priv = walk->private; + struct list_head *migration_lists = priv->migration_lists; + struct damos_migrate_dests *dests = priv->dests; struct folio *folio; pte_t ptent; @@ -663,12 +720,9 @@ static int damos_va_migrate_pte_entry(pte_t *pte, unsigned long addr, if (!folio) return 0; - if (!folio_isolate_lru(folio)) - goto out; + damos_va_migrate_dests_add(folio, walk->vma, addr, dests, + migration_lists); - list_add(&folio->lru, migration_list); - -out: folio_put(folio); return 0; } @@ -721,26 +775,48 @@ static unsigned long damos_va_migrate(struct damon_target *target, unsigned long *sz_filter_passed) { LIST_HEAD(folio_list); + struct damos_va_migrate_private priv; struct mm_struct *mm; + int nr_dests; + int nid; + bool use_target_nid; unsigned long applied = 0; + struct damos_migrate_dests *dests = &s->migrate_dests; struct mm_walk_ops walk_ops = { .pmd_entry = damos_va_migrate_pmd_entry, .pte_entry = damos_va_migrate_pte_entry, .walk_lock = PGWALK_RDLOCK, }; + use_target_nid = dests->nr_dests == 0; + nr_dests = use_target_nid ? 1 : dests->nr_dests; + priv.dests = dests; + priv.migration_lists = kmalloc_array(nr_dests, + sizeof(*priv.migration_lists), GFP_KERNEL); + if (!priv.migration_lists) + return 0; + + for (int i = 0; i < nr_dests; i++) + INIT_LIST_HEAD(&priv.migration_lists[i]); + + mm = damon_get_mm(target); if (!mm) - return 0; + goto free_lists; mmap_read_lock(mm); - walk_page_range(mm, r->ar.start, r->ar.end, &walk_ops, &folio_list); + walk_page_range(mm, r->ar.start, r->ar.end, &walk_ops, &priv); mmap_read_unlock(mm); mmput(mm); - applied = damon_migrate_pages(&folio_list, s->target_nid); - cond_resched(); + for (int i = 0; i < nr_dests; i++) { + nid = use_target_nid ? s->target_nid : dests->node_id_arr[i]; + applied += damon_migrate_pages(&priv.migration_lists[i], nid); + cond_resched(); + } +free_lists: + kfree(priv.migration_lists); return applied * PAGE_SIZE; }