Commit 50533838 authored by Baolin Wang's avatar Baolin Wang Committed by Andrew Morton
Browse files

mm: khugepaged: convert set_huge_pmd() to take a folio 

We've already gotten the stable locked folio in collapse_pte_mapped_thp(),
so just use folio for set_huge_pmd() to set the PMD entry, which is more
straightforward.

Moreover, we will check the folio size in do_set_pmd(), so we can remove
the unnecessary VM_BUG_ON() in set_huge_pmd().  While we are at it, we can
also remove the PageTransHuge(), as it currently has no callers.

Link: https://lkml.kernel.org/r/110c3e1ec5fe7854a0e2c95ffcbc985817180ed7.1747017104.git.baolin.wang@linux.alibaba.com


Signed-off-by: default avatarBaolin Wang <baolin.wang@linux.alibaba.com>
Acked-by: default avatarDavid Hildenbrand <david@redhat.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Mariano Pache <npache@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent a624c424

include/linux/page-flags.h

+0 −15
Original line number Diff line number Diff line
@@ -907,20 +907,6 @@ FOLIO_FLAG_FALSE(partially_mapped) 
#define PG_head_mask ((1UL << PG_head))



#ifdef CONFIG_TRANSPARENT_HUGEPAGE

/*

 * PageHuge() only returns true for hugetlbfs pages, but not for

 * normal or transparent huge pages.

 *

 * PageTransHuge() returns true for both transparent huge and

 * hugetlbfs pages, but not normal pages. PageTransHuge() can only be

 * called only in the core VM paths where hugetlbfs pages can't exist.

 */

static inline int PageTransHuge(const struct page *page)

{

	VM_BUG_ON_PAGE(PageTail(page), page);

	return PageHead(page);

}



/*

 * PageTransCompound returns true for both transparent huge pages

 * and hugetlbfs pages, so it should only be called when it's known
@@ -931,7 +917,6 @@ static inline int PageTransCompound(const struct page *page) 
	return PageCompound(page);

}

#else

TESTPAGEFLAG_FALSE(TransHuge, transhuge)

TESTPAGEFLAG_FALSE(TransCompound, transcompound)

#endif

mm/khugepaged.c

+5 −6
Original line number Diff line number Diff line
@@ -1465,9 +1465,9 @@ static void collect_mm_slot(struct khugepaged_mm_slot *mm_slot) 
}



#ifdef CONFIG_SHMEM

/* hpage must be locked, and mmap_lock must be held */

/* folio must be locked, and mmap_lock must be held */

static int set_huge_pmd(struct vm_area_struct *vma, unsigned long addr,

			pmd_t *pmdp, struct page *hpage)

			pmd_t *pmdp, struct folio *folio, struct page *page)

{

	struct vm_fault vmf = {

		.vma = vma,
@@ -1476,13 +1476,12 @@ static int set_huge_pmd(struct vm_area_struct *vma, unsigned long addr, 
		.pmd = pmdp,

	};



	VM_BUG_ON(!PageTransHuge(hpage));

	mmap_assert_locked(vma->vm_mm);



	if (do_set_pmd(&vmf, hpage))

	if (do_set_pmd(&vmf, page))

		return SCAN_FAIL;



	get_page(hpage);

	folio_get(folio);

	return SCAN_SUCCEED;

}
@@ -1689,7 +1688,7 @@ int collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr, 
maybe_install_pmd:

	/* step 5: install pmd entry */

	result = install_pmd

			? set_huge_pmd(vma, haddr, pmd, &folio->page)

			? set_huge_pmd(vma, haddr, pmd, folio, &folio->page)

			: SCAN_SUCCEED;

	goto drop_folio;

abort: