linux-kernel - [PATCH 05/12] shmem: clear_highpage() if block is not uptodate

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Date: Wed, 15 May 2024 05:57:28 +0000
From: Daniel Gomez <da.gomez@...sung.com>
To: "hughd@...gle.com" <hughd@...gle.com>, "akpm@...ux-foundation.org"
	<akpm@...ux-foundation.org>, "willy@...radead.org" <willy@...radead.org>,
	"jack@...e.cz" <jack@...e.cz>, "mcgrof@...nel.org" <mcgrof@...nel.org>
CC: "linux-mm@...ck.org" <linux-mm@...ck.org>, "linux-xfs@...r.kernel.org"
	<linux-xfs@...r.kernel.org>, "djwong@...nel.org" <djwong@...nel.org>,
	"Pankaj Raghav" <p.raghav@...sung.com>, "dagmcr@...il.com"
	<dagmcr@...il.com>, "yosryahmed@...gle.com" <yosryahmed@...gle.com>,
	"baolin.wang@...ux.alibaba.com" <baolin.wang@...ux.alibaba.com>,
	"ritesh.list@...il.com" <ritesh.list@...il.com>,
	"lsf-pc@...ts.linux-foundation.org" <lsf-pc@...ts.linux-foundation.org>,
	"david@...hat.com" <david@...hat.com>, "chandan.babu@...cle.com"
	<chandan.babu@...cle.com>, "linux-kernel@...r.kernel.org"
	<linux-kernel@...r.kernel.org>, "brauner@...nel.org" <brauner@...nel.org>,
	Daniel Gomez <da.gomez@...sung.com>
Subject: [PATCH 05/12] shmem: clear_highpage() if block is not uptodate

clear_highpage() is called for all the subpages (blocks) in a large
folio when the folio is not uptodate. Do clear the subpages only when
they are not uptodate.

Signed-off-by: Daniel Gomez <da.gomez@...sung.com>
---
 mm/shmem.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/mm/shmem.c b/mm/shmem.c
index 69f3b98fdf7c..04992010225f 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2256,7 +2256,8 @@ static int shmem_get_folio_gfp(struct inode *inode, pgoff_t index,
 		long i, n = folio_nr_pages(folio);
 
 		for (i = 0; i < n; i++)
-			clear_highpage(folio_page(folio, i));
+			if (!shmem_is_block_uptodate(folio, i))
+				clear_highpage(folio_page(folio, i));
 		flush_dcache_folio(folio);
 		shmem_set_range_uptodate(folio, 0, folio_size(folio));
 	}
-- 
2.43.0