Messages in this thread | | | Date | Fri, 21 Jul 2023 07:18:52 +0200 | From | Greg KH <> | Subject | Re: [PATCH 5.15.y] mm/damon/ops-common: atomically test and clear young on ptes and pmds |
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On Mon, Jul 17, 2023 at 07:30:08PM +0000, SeongJae Park wrote: > From: Ryan Roberts <ryan.roberts@arm.com> > > commit c11d34fa139e4b0fb4249a30f37b178353533fa1 upstream. > > It is racy to non-atomically read a pte, then clear the young bit, then > write it back as this could discard dirty information. Further, it is bad > practice to directly set a pte entry within a table. Instead clearing > young must go through the arch-provided helper, > ptep_test_and_clear_young() to ensure it is modified atomically and to > give the arch code visibility and allow it to check (and potentially > modify) the operation. > > Link: https://lkml.kernel.org/r/20230602092949.545577-3-ryan.roberts@arm.com > Fixes: 3f49584b262c ("mm/damon: implement primitives for the virtual memory address spaces"). > Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> > Reviewed-by: Zi Yan <ziy@nvidia.com> > Reviewed-by: SeongJae Park <sj@kernel.org> > Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> > Cc: Christoph Hellwig <hch@lst.de> > Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> > Cc: Lorenzo Stoakes <lstoakes@gmail.com> > Cc: Matthew Wilcox (Oracle) <willy@infradead.org> > Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> > Cc: Yu Zhao <yuzhao@google.com> > Cc: <stable@vger.kernel.org> > Signed-off-by: Andrew Morton <akpm@linux-foundation.org> > Signed-off-by: SeongJae Park <sj@kernel.org> > --- > This is a manual backport of the commit, which cannot cleanly > cherry-picked on 5.15.y[1], on 5.15.y, specifically 5.15.120. > > [1] https://lore.kernel.org/stable/2023071613-reminder-relapse-b922@gregkh/
Now queued up, thanks.
greg k-h
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