Re: [PATCH 1/3] mm: change huge_ptep_clear_flush() to return the original pte
From: Baolin Wang <baolin.wang@linux.alibaba.com>
Date: 2022-05-06 03:01:50
Also in:
linux-arch, linux-arm-kernel, linux-mips, linux-mm, linux-s390, linux-sh, lkml, sparclinux
On 5/6/2022 7:15 AM, Mike Kravetz wrote:
On 4/29/22 01:14, Baolin Wang wrote:quoted
It is incorrect to use ptep_clear_flush() to nuke a hugetlb page table when unmapping or migrating a hugetlb page, and will change to use huge_ptep_clear_flush() instead in the following patches. So this is a preparation patch, which changes the huge_ptep_clear_flush() to return the original pte to help to nuke a hugetlb page table. Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> --- arch/arm64/include/asm/hugetlb.h | 4 ++-- arch/arm64/mm/hugetlbpage.c | 12 +++++------- arch/ia64/include/asm/hugetlb.h | 4 ++-- arch/mips/include/asm/hugetlb.h | 9 ++++++--- arch/parisc/include/asm/hugetlb.h | 4 ++-- arch/powerpc/include/asm/hugetlb.h | 9 ++++++--- arch/s390/include/asm/hugetlb.h | 6 +++--- arch/sh/include/asm/hugetlb.h | 4 ++-- arch/sparc/include/asm/hugetlb.h | 4 ++-- include/asm-generic/hugetlb.h | 4 ++-- 10 files changed, 32 insertions(+), 28 deletions(-)The above changes look straight forward. Happy that you Cc'ed impacted arch maintainers so they can at least have a look. The only user of huge_ptep_clear_flush() today is hugetlb_cow/wp() in mm/hugetlb.c. Any reason why you did not change that code? At least
Cause we did not use the return value of huge_ptep_clear_flush() in mm/hugetlb.c.
cast the return of huge_ptep_clear_flush() to void with a comment?
Sure. Will add an explicit casting in next version.
Not absolutely necessary. Acked-by: Mike Kravetz <redacted>
Thanks.