Commit 80b2270a authored Jun 24, 2021 by Hugh Dickins Committed by Sasha Levin Jun 30, 2021

mm: page_vma_mapped_walk(): prettify PVMW_MIGRATION block

page_vma_mapped_walk() cleanup: rearrange the !pmd_present() block to
follow the same "return not_found, return not_found, return true"
pattern as the block above it (note: returning not_found there is never
premature, since existence or prior existence of huge pmd guarantees
good alignment).

Link: https://lkml.kernel.org/r/378c8650-1488-2edf-9647-32a53cf2e21@google.com


Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Wang Yugui <wangyugui@e16-tech.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent ef161cca

mm/page_vma_mapped.c

+14 −16

Original line number	Diff line number	Diff line
		@@ -193,24 +193,22 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw)
		if (pmd_page(pmde) != page)
		return not_found(pvmw);
		return true;
		} else if (!pmd_present(pmde)) {
		if (thp_migration_supported()) {
		if (!(pvmw->flags & PVMW_MIGRATION))
		return not_found(pvmw);
		if (is_migration_entry(pmd_to_swp_entry(pmde))) {
		swp_entry_t entry = pmd_to_swp_entry(pmde);
		}
		if (!pmd_present(pmde)) {
		swp_entry_t entry;

		if (migration_entry_to_page(entry) != page)
		if (!thp_migration_supported() \|\|
		!(pvmw->flags & PVMW_MIGRATION))
		return not_found(pvmw);
		entry = pmd_to_swp_entry(pmde);
		if (!is_migration_entry(entry) \|\|
		migration_entry_to_page(entry) != page)
		return not_found(pvmw);
		return true;
		}
		}
		return not_found(pvmw);
		} else {
		/* THP pmd was split under us: handle on pte level */
		spin_unlock(pvmw->ptl);
		pvmw->ptl = NULL;
		}
		} else if (!pmd_present(pmde)) {
		/*
		* If PVMW_SYNC, take and drop THP pmd lock so that we