linux-kernel - [PATCH 05/25] mm: don't clear ->mapping in hmm_devmem

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Message-Id: <20190626122724.13313-6-hch@lst.de>
Date:   Wed, 26 Jun 2019 14:27:04 +0200
From:   Christoph Hellwig <hch@....de>
To:     Dan Williams <dan.j.williams@...el.com>,
        Jérôme Glisse <jglisse@...hat.com>,
        Jason Gunthorpe <jgg@...lanox.com>,
        Ben Skeggs <bskeggs@...hat.com>
Cc:     linux-mm@...ck.org, nouveau@...ts.freedesktop.org,
        dri-devel@...ts.freedesktop.org, linux-nvdimm@...ts.01.org,
        linux-pci@...r.kernel.org, linux-kernel@...r.kernel.org,
        John Hubbard <jhubbard@...dia.com>
Subject: [PATCH 05/25] mm: don't clear ->mapping in hmm_devmem_free

->mapping isn't even used by HMM users, and the field at the same offset
in the zone_device part of the union is declared as pad.  (Which btw is
rather confusing, as DAX uses ->pgmap and ->mapping from two different
sides of the union, but DAX doesn't use hmm_devmem_free).

Signed-off-by: Christoph Hellwig <hch@....de>
Reviewed-by: Jason Gunthorpe <jgg@...lanox.com>
Reviewed-by: John Hubbard <jhubbard@...dia.com>
---
 mm/hmm.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/mm/hmm.c b/mm/hmm.c
index 376159a769fb..e7dd2ab8f9ab 100644
--- a/mm/hmm.c
+++ b/mm/hmm.c
@@ -1383,8 +1383,6 @@ static void hmm_devmem_free(struct page *page, void *data)
 {
 	struct hmm_devmem *devmem = data;
 
-	page->mapping = NULL;
-
 	devmem->ops->free(devmem, page);
 }
 
-- 
2.20.1