| Message ID | 1655692482-28797-1-git-send-email-baolin.wang@linux.alibaba.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm/damon: Use set_huge_pte_at() to make huge pte old | expand |
Hi Baolin, On Mon, 20 Jun 2022 10:34:42 +0800 Baolin Wang <baolin.wang@linux.alibaba.com> wrote: > The huge_ptep_set_access_flags() can not make the huge pte old according > to the discussion [1], that means we will always mornitor the young state > of the hugetlb though we stopped accessing the hugetlb, as a result DAMON > will get inaccurate accessing statistics. > > So changing to use set_huge_pte_at() to make the huge pte old to fix this > issue. > > [1] https://lore.kernel.org/all/Yqy97gXI4Nqb7dYo@arm.com/ > > Fixes: 49f4203aae06 ("mm/damon: add access checking for hugetlb pages") As the commit has merged in from v5.17, I guess it would be better to do below? Cc: <stable@vger.kernel.org> > Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Other than that, Reviewed-by: SeongJae Park <sj@kernel.org> Thanks, SJ > --- > mm/damon/vaddr.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/mm/damon/vaddr.c b/mm/damon/vaddr.c > index 5767be72c181..d24148a8149f 100644 > --- a/mm/damon/vaddr.c > +++ b/mm/damon/vaddr.c > @@ -337,8 +337,7 @@ static void damon_hugetlb_mkold(pte_t *pte, struct mm_struct *mm, > if (pte_young(entry)) { > referenced = true; > entry = pte_mkold(entry); > - huge_ptep_set_access_flags(vma, addr, pte, entry, > - vma->vm_flags & VM_WRITE); > + set_huge_pte_at(mm, addr, pte, entry); > } > > #ifdef CONFIG_MMU_NOTIFIER > -- > 2.27.0
Hi SeongJae, On 6/21/2022 1:27 AM, SeongJae Park wrote: > Hi Baolin, > > On Mon, 20 Jun 2022 10:34:42 +0800 Baolin Wang <baolin.wang@linux.alibaba.com> wrote: > >> The huge_ptep_set_access_flags() can not make the huge pte old according >> to the discussion [1], that means we will always mornitor the young state >> of the hugetlb though we stopped accessing the hugetlb, as a result DAMON >> will get inaccurate accessing statistics. >> >> So changing to use set_huge_pte_at() to make the huge pte old to fix this >> issue. >> >> [1] https://lore.kernel.org/all/Yqy97gXI4Nqb7dYo@arm.com/ >> >> Fixes: 49f4203aae06 ("mm/damon: add access checking for hugetlb pages") > > As the commit has merged in from v5.17, I guess it would be better to do below? > > Cc: <stable@vger.kernel.org> Yes, thanks for reminding. Hope Andrew can help to add the stable tag when picking up this patch. > >> Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> > > Other than that, > > Reviewed-by: SeongJae Park <sj@kernel.org> Thanks.
On 06/20/22 10:34, Baolin Wang wrote: > The huge_ptep_set_access_flags() can not make the huge pte old according > to the discussion [1], that means we will always mornitor the young state > of the hugetlb though we stopped accessing the hugetlb, as a result DAMON > will get inaccurate accessing statistics. > > So changing to use set_huge_pte_at() to make the huge pte old to fix this > issue. > > [1] https://lore.kernel.org/all/Yqy97gXI4Nqb7dYo@arm.com/ > > Fixes: 49f4203aae06 ("mm/damon: add access checking for hugetlb pages") > Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Thanks, Acked-by: Mike Kravetz <mike.kravetz@oracle.com>
On Mon, Jun 20, 2022 at 10:34:42AM +0800, Baolin Wang wrote: > The huge_ptep_set_access_flags() can not make the huge pte old according > to the discussion [1], that means we will always mornitor the young state > of the hugetlb though we stopped accessing the hugetlb, as a result DAMON > will get inaccurate accessing statistics. > > So changing to use set_huge_pte_at() to make the huge pte old to fix this > issue. > > [1] https://lore.kernel.org/all/Yqy97gXI4Nqb7dYo@arm.com/ > > Fixes: 49f4203aae06 ("mm/damon: add access checking for hugetlb pages") > Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> The changes make sense to me. Reviewed-by: Muchun Song <songmuchun@bytedance.com>
diff --git a/mm/damon/vaddr.c b/mm/damon/vaddr.c index 5767be72c181..d24148a8149f 100644 --- a/mm/damon/vaddr.c +++ b/mm/damon/vaddr.c @@ -337,8 +337,7 @@ static void damon_hugetlb_mkold(pte_t *pte, struct mm_struct *mm, if (pte_young(entry)) { referenced = true; entry = pte_mkold(entry); - huge_ptep_set_access_flags(vma, addr, pte, entry, - vma->vm_flags & VM_WRITE); + set_huge_pte_at(mm, addr, pte, entry); } #ifdef CONFIG_MMU_NOTIFIER
The huge_ptep_set_access_flags() can not make the huge pte old according to the discussion [1], that means we will always mornitor the young state of the hugetlb though we stopped accessing the hugetlb, as a result DAMON will get inaccurate accessing statistics. So changing to use set_huge_pte_at() to make the huge pte old to fix this issue. [1] https://lore.kernel.org/all/Yqy97gXI4Nqb7dYo@arm.com/ Fixes: 49f4203aae06 ("mm/damon: add access checking for hugetlb pages") Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> --- mm/damon/vaddr.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)