diff mbox series

[v2,04/28] gup: Optimise compound_range_next()

Message ID	20220110042406.499429-5-willy@infradead.org (mailing list archive)
State	New
Headers	show Return-Path: <owner-linux-mm@kvack.org> From: "Matthew Wilcox (Oracle)" <willy@infradead.org> To: linux-mm@kvack.org Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>, John Hubbard <jhubbard@nvidia.com>, Christoph Hellwig <hch@infradead.org>, William Kucharski <william.kucharski@oracle.com>, linux-kernel@vger.kernel.org, Jason Gunthorpe <jgg@ziepe.ca> Subject: [PATCH v2 04/28] gup: Optimise compound_range_next() Date: Mon, 10 Jan 2022 04:23:42 +0000 Message-Id: <20220110042406.499429-5-willy@infradead.org> In-Reply-To: <20220110042406.499429-1-willy@infradead.org> References: <20220110042406.499429-1-willy@infradead.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org Precedence: bulk
Series	Convert GUP to folios \| expand [v2,00/28] Convert GUP to folios [v2,01/28] gup: Remove for_each_compound_range() [v2,02/28] gup: Remove for_each_compound_head() [v2,03/28] gup: Change the calling convention for compound_range_next() [v2,04/28] gup: Optimise compound_range_next() [v2,05/28] gup: Change the calling convention for compound_next() [v2,06/28] gup: Fix some contiguous memmap assumptions [v2,07/28] gup: Remove an assumption of a contiguous memmap [v2,08/28] gup: Handle page split race more efficiently [v2,09/28] gup: Turn hpage_pincount_add() into page_pincount_add() [v2,10/28] gup: Turn hpage_pincount_sub() into page_pincount_sub() [v2,11/28] mm: Make compound_pincount always available [v2,12/28] mm: Add folio_put_refs() [v2,13/28] mm: Add folio_pincount_ptr() [v2,14/28] mm: Convert page_maybe_dma_pinned() to use a folio [v2,15/28] gup: Add try_get_folio() and try_grab_folio() [v2,16/28] mm: Remove page_cache_add_speculative() and page_cache_get_speculative() [v2,17/28] gup: Add gup_put_folio() [v2,18/28] hugetlb: Use try_grab_folio() instead of try_grab_compound_head() [v2,19/28] gup: Convert try_grab_page() to call try_grab_folio() [v2,20/28] gup: Convert gup_pte_range() to use a folio [v2,21/28] gup: Convert gup_hugepte() to use a folio [v2,22/28] gup: Convert gup_huge_pmd() to use a folio [v2,23/28] gup: Convert gup_huge_pud() to use a folio [v2,24/28] gup: Convert gup_huge_pgd() to use a folio [v2,25/28] gup: Convert compound_next() to gup_folio_next() [v2,26/28] gup: Convert compound_range_next() to gup_folio_range_next() [v2,27/28] mm: Add isolate_lru_folio() [v2,28/28] gup: Convert check_and_migrate_movable_pages() to use a folio

Commit Message

Matthew Wilcox (Oracle) Jan. 10, 2022, 4:23 a.m. UTC

By definition, a compound page has an order >= 1, so the second half
of the test was redundant.  Also, this cannot be a tail page since
it's the result of calling compound_head(), so use PageHead() instead
of PageCompound().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
 mm/gup.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Christoph Hellwig Jan. 10, 2022, 8:26 a.m. UTC | #1

On Mon, Jan 10, 2022 at 04:23:42AM +0000, Matthew Wilcox (Oracle) wrote:
> By definition, a compound page has an order >= 1, so the second half
> of the test was redundant.  Also, this cannot be a tail page since
> it's the result of calling compound_head(), so use PageHead() instead
> of PageCompound().
> 
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

Looks good,

Reviewed-by: Christoph Hellwig <hch@lst.de>

John Hubbard Jan. 11, 2022, 1:16 a.m. UTC | #2

On 1/9/22 20:23, Matthew Wilcox (Oracle) wrote:
> By definition, a compound page has an order >= 1, so the second half
> of the test was redundant.  Also, this cannot be a tail page since
> it's the result of calling compound_head(), so use PageHead() instead
> of PageCompound().
> 
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> ---

Reviewed-by: John Hubbard <jhubbard@nvidia.com>


thanks,

diff mbox series

Patch

diff --git a/mm/gup.c b/mm/gup.c
index 3c93d2fdf4da..6eedca605b3d 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -237,7 +237,7 @@  static inline struct page *compound_range_next(unsigned long i,
 
 	next = start + i;
 	page = compound_head(next);
-	if (PageCompound(page) && compound_order(page) >= 1)
+	if (PageHead(page))
 		nr = min_t(unsigned int,
 			   page + compound_nr(page) - next, npages - i);