Commit 256b0c7f authored by Bijan Tabatabai's avatar Bijan Tabatabai Committed by Andrew Morton
Browse files

mm/damon/vaddr: add vaddr versions of migrate_{hot,cold} 

migrate_{hot,cold} are paddr schemes that are used to migrate hot/cold
data to a specified node.  However, these schemes are only available when
doing physical address monitoring.  This patch adds an implementation for
them virtual address monitoring as well.

Link: https://lkml.kernel.org/r/20250709005952.17776-10-bijan311@gmail.com


Co-developed-by: default avatarRavi Shankar Jonnalagadda <ravis.opensrc@micron.com>
Signed-off-by: default avatarRavi Shankar Jonnalagadda <ravis.opensrc@micron.com>
Signed-off-by: default avatarBijan Tabatabai <bijantabatab@micron.com>
Reviewed-by: default avatarSeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 13dde31d

mm/damon/vaddr.c

+98 −0
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 
#include <linux/pagewalk.h>

#include <linux/sched/mm.h>



#include "../internal.h"

#include "ops-common.h"



#ifdef CONFIG_DAMON_VADDR_KUNIT_TEST
@@ -610,6 +611,68 @@ static unsigned int damon_va_check_accesses(struct damon_ctx *ctx) 
	return max_nr_accesses;

}



#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 folio *folio;

	spinlock_t *ptl;

	pmd_t pmde;



	ptl = pmd_lock(walk->mm, pmd);

	pmde = pmdp_get(pmd);



	if (!pmd_present(pmde) || !pmd_trans_huge(pmde))

		goto unlock;



	/* Tell page walk code to not split the PMD */

	walk->action = ACTION_CONTINUE;



	folio = damon_get_folio(pmd_pfn(pmde));

	if (!folio)

		goto unlock;



	if (!folio_isolate_lru(folio))

		goto put_folio;



	list_add(&folio->lru, migration_list);



put_folio:

	folio_put(folio);

unlock:

	spin_unlock(ptl);

	return 0;

}

#else

#define damos_va_migrate_pmd_entry NULL

#endif /* CONFIG_TRANSPARENT_HUGEPAGE */



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 folio *folio;

	pte_t ptent;



	ptent = ptep_get(pte);

	if (pte_none(ptent) || !pte_present(ptent))

		return 0;



	folio = damon_get_folio(pte_pfn(ptent));

	if (!folio)

		return 0;



	if (!folio_isolate_lru(folio))

		goto out;



	list_add(&folio->lru, migration_list);



out:

	folio_put(folio);

	return 0;

}



/*

 * Functions for the target validity check and cleanup

 */
@@ -653,6 +716,34 @@ static unsigned long damos_madvise(struct damon_target *target, 
}

#endif	/* CONFIG_ADVISE_SYSCALLS */



static unsigned long damos_va_migrate(struct damon_target *target,

		struct damon_region *r, struct damos *s,

		unsigned long *sz_filter_passed)

{

	LIST_HEAD(folio_list);

	struct mm_struct *mm;

	unsigned long applied = 0;

	struct mm_walk_ops walk_ops = {

		.pmd_entry = damos_va_migrate_pmd_entry,

		.pte_entry = damos_va_migrate_pte_entry,

		.walk_lock = PGWALK_RDLOCK,

	};



	mm = damon_get_mm(target);

	if (!mm)

		return 0;



	mmap_read_lock(mm);

	walk_page_range(mm, r->ar.start, r->ar.end, &walk_ops, &folio_list);

	mmap_read_unlock(mm);

	mmput(mm);



	applied = damon_migrate_pages(&folio_list, s->target_nid);

	cond_resched();



	return applied * PAGE_SIZE;

}



static unsigned long damon_va_apply_scheme(struct damon_ctx *ctx,

		struct damon_target *t, struct damon_region *r,

		struct damos *scheme, unsigned long *sz_filter_passed)
@@ -675,6 +766,9 @@ static unsigned long damon_va_apply_scheme(struct damon_ctx *ctx, 
	case DAMOS_NOHUGEPAGE:

		madv_action = MADV_NOHUGEPAGE;

		break;

	case DAMOS_MIGRATE_HOT:

	case DAMOS_MIGRATE_COLD:

		return damos_va_migrate(t, r, scheme, sz_filter_passed);

	case DAMOS_STAT:

		return 0;

	default:
@@ -695,6 +789,10 @@ static int damon_va_scheme_score(struct damon_ctx *context, 
	switch (scheme->action) {

	case DAMOS_PAGEOUT:

		return damon_cold_score(context, r, scheme);

	case DAMOS_MIGRATE_HOT:

		return damon_hot_score(context, r, scheme);

	case DAMOS_MIGRATE_COLD:

		return damon_cold_score(context, r, scheme);

	default:

		break;

	}