Commit 63f39737 authored by Yueyang Pan's avatar Yueyang Pan Committed by Andrew Morton
Browse files

mm/damon/vaddr: support stat-purpose DAMOS filters 

This patch extends DAMOS_STAT handling of the DAMON operations sets for
virtual address spaces for ops-level DAMOS filters.  It leverages the
walk_page_range to walk the page table and gets the folio from page table.
The last folio scanned is stored in damos->last_applied to prevent double
counting.

Link: https://lkml.kernel.org/r/264a4b5ea202fd73c01b349c9694d8bf9978c441.1754135312.git.pyyjason@gmail.com


Signed-off-by: default avatarYueyang Pan <pyyjason@gmail.com>
Reviewed-by: default avatarSeongJae Park <sj@kernel.org>
Cc: Usama Arif <usamaarif642@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 408b299a

mm/damon/vaddr.c

+102 −1
Original line number Diff line number Diff line
@@ -890,6 +890,107 @@ static unsigned long damos_va_migrate(struct damon_target *target, 
	return applied * PAGE_SIZE;

}



struct damos_va_stat_private {

	struct damos *scheme;

	unsigned long *sz_filter_passed;

};



static inline bool damos_va_invalid_folio(struct folio *folio,

		struct damos *s)

{

	return !folio || folio == s->last_applied;

}



static int damos_va_stat_pmd_entry(pmd_t *pmd, unsigned long addr,

		unsigned long next, struct mm_walk *walk)

{

	struct damos_va_stat_private *priv = walk->private;

	struct damos *s = priv->scheme;

	unsigned long *sz_filter_passed = priv->sz_filter_passed;

	struct vm_area_struct *vma = walk->vma;

	struct folio *folio;

	spinlock_t *ptl;

	pte_t *start_pte, *pte, ptent;

	int nr;



#ifdef CONFIG_TRANSPARENT_HUGEPAGE

	if (pmd_trans_huge(*pmd)) {

		pmd_t pmde;



		ptl = pmd_trans_huge_lock(pmd, vma);

		if (!ptl)

			return 0;

		pmde = pmdp_get(pmd);

		if (!pmd_present(pmde))

			goto huge_unlock;



		folio = vm_normal_folio_pmd(vma, addr, pmde);



		if (damos_va_invalid_folio(folio, s))

			goto huge_unlock;



		if (!damos_va_filter_out(s, folio, vma, addr, NULL, pmd))

			*sz_filter_passed += folio_size(folio);

		s->last_applied = folio;



huge_unlock:

		spin_unlock(ptl);

		return 0;

	}

#endif

	start_pte = pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);

	if (!start_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))

			continue;



		folio = vm_normal_folio(vma, addr, ptent);



		if (damos_va_invalid_folio(folio, s))

			continue;



		if (!damos_va_filter_out(s, folio, vma, addr, pte, NULL))

			*sz_filter_passed += folio_size(folio);

		nr = folio_nr_pages(folio);

		s->last_applied = folio;

	}

	pte_unmap_unlock(start_pte, ptl);

	return 0;

}



static unsigned long damos_va_stat(struct damon_target *target,

		struct damon_region *r, struct damos *s,

		unsigned long *sz_filter_passed)

{

	struct damos_va_stat_private priv;

	struct mm_struct *mm;

	struct mm_walk_ops walk_ops = {

		.pmd_entry = damos_va_stat_pmd_entry,

		.walk_lock = PGWALK_RDLOCK,

	};



	priv.scheme = s;

	priv.sz_filter_passed = sz_filter_passed;



	if (!damos_ops_has_filter(s))

		return 0;



	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, &priv);

	mmap_read_unlock(mm);

	mmput(mm);

	return 0;

}



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)
@@ -916,7 +1017,7 @@ static unsigned long damon_va_apply_scheme(struct damon_ctx *ctx, 
	case DAMOS_MIGRATE_COLD:

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

	case DAMOS_STAT:

		return 0;

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

	default:

		/*

		 * DAMOS actions that are not yet supported by 'vaddr'.