Re: [PATCH v2 05/14] mm/sparc: Change pXd_huge() behavior to exclude swap entries

From: Muchun Song <muchun.song@linux.dev>
To: Peter Xu <peterx@redhat.com>
Cc: linux-arm-kernel@lists.infradead.org,
	Andreas Larsson <andreas@gaisler.com>,
	x86@kernel.org, LKML <linux-kernel@vger.kernel.org>,
	Matthew Wilcox <willy@infradead.org>,
	Linux-MM <linux-mm@kvack.org>, Jason Gunthorpe <jgg@nvidia.com>,
	sparclinux@vger.kernel.org,
	Andrew Morton <akpm@linux-foundation.org>,
	linuxppc-dev@lists.ozlabs.org,
	"David S . Miller" <davem@davemloft.net>,
	Mike Rapoport <rppt@kernel.org>
Subject: Re: [PATCH v2 05/14] mm/sparc: Change pXd_huge() behavior to exclude swap entries
Date: Tue, 19 Mar 2024 12:25:39 +0800	[thread overview]
Message-ID: <744C19CB-4AE0-472B-ABD8-2064EB04FDA0@linux.dev> (raw)
In-Reply-To: <20240318200404.448346-6-peterx@redhat.com>

> On Mar 19, 2024, at 04:03, peterx@redhat.com wrote:
> 
> From: Peter Xu <peterx@redhat.com>
> 
> Please refer to the previous patch on the reasoning for x86.  Now sparc is
> the only architecture that will allow swap entries to be reported as
> pXd_huge().  After this patch, all architectures should forbid swap entries
> in pXd_huge().
> 
> Cc: David S. Miller <davem@davemloft.net>
> Cc: Andreas Larsson <andreas@gaisler.com>
> Cc: sparclinux@vger.kernel.org
> Signed-off-by: Peter Xu <peterx@redhat.com>
> ---
> arch/sparc/mm/hugetlbpage.c | 6 ++----
> 1 file changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/sparc/mm/hugetlbpage.c b/arch/sparc/mm/hugetlbpage.c
> index b432500c13a5..d31c2cec35c9 100644
> --- a/arch/sparc/mm/hugetlbpage.c
> +++ b/arch/sparc/mm/hugetlbpage.c
> @@ -409,14 +409,12 @@ pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
> 
> int pmd_huge(pmd_t pmd)
> {
> - 	return !pmd_none(pmd) &&
> - 	(pmd_val(pmd) & (_PAGE_VALID|_PAGE_PMD_HUGE)) != _PAGE_VALID;
> + 	return pmd_leaf(pmd);;

There is a redundant semicolon in the end.

Thanks.

> }
> 
> int pud_huge(pud_t pud)
> {
> - 	return !pud_none(pud) &&
> - 	(pud_val(pud) & (_PAGE_VALID|_PAGE_PUD_HUGE)) != _PAGE_VALID;
> + 	return pud_leaf(pud);
> }
> 
> static void hugetlb_free_pte_range(struct mmu_gather *tlb, pmd_t *pmd,
> -- 
> 2.44.0
> 