Commit 09efc56a authored by SeongJae Park's avatar SeongJae Park Committed by Andrew Morton
Browse files

mm/damon/vaddr: consistently use only pmd_entry for damos_migrate 

For page table walks, it is usual [1] to have only one pmd entry function.
The vaddr.c code for DAMOS_MIGRATE_{HOT,COLD} is not following the
pattern.  Instead, it uses both pmd and pte entry functions without a
special reason.  Refactor it to use only the pmd entry function, to make
the code under mm/ more consistent.

Link: https://lkml.kernel.org/r/20251112154114.66053-6-sj@kernel.org


Signed-off-by: default avatarSeongJae Park <sj@kernel.org>
Suggested-by: default avatarDavid Hildenbrand <david@kernel.org>
Cc: Bill Wendling <morbo@google.com>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: David Gow <davidgow@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent f0eb046c

mm/damon/vaddr.c

+37 −47
Original line number Diff line number Diff line
@@ -697,7 +697,6 @@ static void damos_va_migrate_dests_add(struct folio *folio, 
	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)

{
@@ -707,58 +706,49 @@ static int damos_va_migrate_pmd_entry(pmd_t *pmd, unsigned long addr, 
	struct damos_migrate_dests *dests = &s->migrate_dests;

	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;

	pte_t *start_pte, *pte, ptent;

	int nr;



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

	walk->action = ACTION_CONTINUE;

#ifdef CONFIG_TRANSPARENT_HUGEPAGE

	ptl = pmd_trans_huge_lock(pmd, walk->vma);

	if (ptl) {

		pmd_t pmde = pmdp_get(pmd);



		if (!pmd_present(pmde))

			goto huge_out;

		folio = vm_normal_folio_pmd(walk->vma, addr, pmde);

		if (!folio)

		goto unlock;



			goto huge_out;

		if (damos_va_filter_out(s, folio, walk->vma, addr, NULL, pmd))

		goto unlock;



			goto huge_out;

		damos_va_migrate_dests_add(folio, walk->vma, addr, dests,

				migration_lists);



unlock:

huge_out:

		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 damos_va_migrate_private *priv = walk->private;

	struct list_head *migration_lists = priv->migration_lists;

	struct damos *s = priv->scheme;

	struct damos_migrate_dests *dests = &s->migrate_dests;

	struct folio *folio;

	pte_t ptent;

	start_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);

	if (!pte)

		return 0;



	for (; addr < next; pte += nr, addr += nr * PAGE_SIZE) {

		nr = 1;

		ptent = ptep_get(pte);

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

		return 0;



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

			continue;

		folio = vm_normal_folio(walk->vma, addr, ptent);

		if (!folio)

		return 0;



			continue;

		if (damos_va_filter_out(s, folio, walk->vma, addr, pte, NULL))

			return 0;



		damos_va_migrate_dests_add(folio, walk->vma, addr, dests,

				migration_lists);

		nr = folio_nr_pages(folio);

	}

	pte_unmap_unlock(start_pte, ptl);

	return 0;

}
@@ -824,7 +814,7 @@ static unsigned long damos_va_migrate(struct damon_target *target, 
	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,

		.pte_entry = NULL,

		.walk_lock = PGWALK_RDLOCK,

	};