| Message ID | 20231204142146.91437-4-david@redhat.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm/rmap: interface overhaul | expand |
On 12/4/23 22:21, David Hildenbrand wrote: > hugetlb rmap handling differs quite a lot from "ordinary" rmap code. > For example, hugetlb currently only supports entire mappings, and treats > any mapping as mapped using a single "logical PTE". Let's move it out > of the way so we can overhaul our "ordinary" rmap. > implementation/interface. > > Right now we're using page_dup_file_rmap() in some cases where "ordinary" > rmap code would have used page_add_file_rmap(). So let's introduce and > use hugetlb_add_file_rmap() instead. We won't be adding a > "hugetlb_dup_file_rmap()" functon for the fork() case, as it would be > doing the same: "dup" is just an optimization for "add". > > What remains is a single page_dup_file_rmap() call in fork() code. > > Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Yin Fengwei <fengwei.yin@intel.com> > --- > include/linux/rmap.h | 7 +++++++ > mm/hugetlb.c | 6 +++--- > mm/migrate.c | 2 +- > 3 files changed, 11 insertions(+), 4 deletions(-) > > diff --git a/include/linux/rmap.h b/include/linux/rmap.h > index e8d1dc1d5361f..0a81e8420a961 100644 > --- a/include/linux/rmap.h > +++ b/include/linux/rmap.h > @@ -208,6 +208,13 @@ void hugetlb_add_anon_rmap(struct folio *, struct vm_area_struct *, > void hugetlb_add_new_anon_rmap(struct folio *, struct vm_area_struct *, > unsigned long address); > > +static inline void hugetlb_add_file_rmap(struct folio *folio) > +{ > + VM_WARN_ON_FOLIO(folio_test_anon(folio), folio); > + > + atomic_inc(&folio->_entire_mapcount); > +} > + > static inline void hugetlb_remove_rmap(struct folio *folio) > { > atomic_dec(&folio->_entire_mapcount); > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index d17bb53b19ff2..541a8f38cfdc7 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -5401,7 +5401,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, > * sleep during the process. > */ > if (!folio_test_anon(pte_folio)) { > - page_dup_file_rmap(&pte_folio->page, true); > + hugetlb_add_file_rmap(pte_folio); > } else if (page_try_dup_anon_rmap(&pte_folio->page, > true, src_vma)) { > pte_t src_pte_old = entry; > @@ -6272,7 +6272,7 @@ static vm_fault_t hugetlb_no_page(struct mm_struct *mm, > if (anon_rmap) > hugetlb_add_new_anon_rmap(folio, vma, haddr); > else > - page_dup_file_rmap(&folio->page, true); > + hugetlb_add_file_rmap(folio); > new_pte = make_huge_pte(vma, &folio->page, ((vma->vm_flags & VM_WRITE) > && (vma->vm_flags & VM_SHARED))); > /* > @@ -6723,7 +6723,7 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_pte, > goto out_release_unlock; > > if (folio_in_pagecache) > - page_dup_file_rmap(&folio->page, true); > + hugetlb_add_file_rmap(folio); > else > hugetlb_add_new_anon_rmap(folio, dst_vma, dst_addr); > > diff --git a/mm/migrate.c b/mm/migrate.c > index 4cb849fa0dd2c..de9d94b99ab78 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -252,7 +252,7 @@ static bool remove_migration_pte(struct folio *folio, > hugetlb_add_anon_rmap(folio, vma, pvmw.address, > rmap_flags); > else > - page_dup_file_rmap(new, true); > + hugetlb_add_file_rmap(folio); > set_huge_pte_at(vma->vm_mm, pvmw.address, pvmw.pte, pte, > psize); > } else
diff --git a/include/linux/rmap.h b/include/linux/rmap.h index e8d1dc1d5361f..0a81e8420a961 100644 --- a/include/linux/rmap.h +++ b/include/linux/rmap.h @@ -208,6 +208,13 @@ void hugetlb_add_anon_rmap(struct folio *, struct vm_area_struct *, void hugetlb_add_new_anon_rmap(struct folio *, struct vm_area_struct *, unsigned long address); +static inline void hugetlb_add_file_rmap(struct folio *folio) +{ + VM_WARN_ON_FOLIO(folio_test_anon(folio), folio); + + atomic_inc(&folio->_entire_mapcount); +} + static inline void hugetlb_remove_rmap(struct folio *folio) { atomic_dec(&folio->_entire_mapcount); diff --git a/mm/hugetlb.c b/mm/hugetlb.c index d17bb53b19ff2..541a8f38cfdc7 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -5401,7 +5401,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, * sleep during the process. */ if (!folio_test_anon(pte_folio)) { - page_dup_file_rmap(&pte_folio->page, true); + hugetlb_add_file_rmap(pte_folio); } else if (page_try_dup_anon_rmap(&pte_folio->page, true, src_vma)) { pte_t src_pte_old = entry; @@ -6272,7 +6272,7 @@ static vm_fault_t hugetlb_no_page(struct mm_struct *mm, if (anon_rmap) hugetlb_add_new_anon_rmap(folio, vma, haddr); else - page_dup_file_rmap(&folio->page, true); + hugetlb_add_file_rmap(folio); new_pte = make_huge_pte(vma, &folio->page, ((vma->vm_flags & VM_WRITE) && (vma->vm_flags & VM_SHARED))); /* @@ -6723,7 +6723,7 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_pte, goto out_release_unlock; if (folio_in_pagecache) - page_dup_file_rmap(&folio->page, true); + hugetlb_add_file_rmap(folio); else hugetlb_add_new_anon_rmap(folio, dst_vma, dst_addr); diff --git a/mm/migrate.c b/mm/migrate.c index 4cb849fa0dd2c..de9d94b99ab78 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -252,7 +252,7 @@ static bool remove_migration_pte(struct folio *folio, hugetlb_add_anon_rmap(folio, vma, pvmw.address, rmap_flags); else - page_dup_file_rmap(new, true); + hugetlb_add_file_rmap(folio); set_huge_pte_at(vma->vm_mm, pvmw.address, pvmw.pte, pte, psize); } else
hugetlb rmap handling differs quite a lot from "ordinary" rmap code. For example, hugetlb currently only supports entire mappings, and treats any mapping as mapped using a single "logical PTE". Let's move it out of the way so we can overhaul our "ordinary" rmap. implementation/interface. Right now we're using page_dup_file_rmap() in some cases where "ordinary" rmap code would have used page_add_file_rmap(). So let's introduce and use hugetlb_add_file_rmap() instead. We won't be adding a "hugetlb_dup_file_rmap()" functon for the fork() case, as it would be doing the same: "dup" is just an optimization for "add". What remains is a single page_dup_file_rmap() call in fork() code. Signed-off-by: David Hildenbrand <david@redhat.com> --- include/linux/rmap.h | 7 +++++++ mm/hugetlb.c | 6 +++--- mm/migrate.c | 2 +- 3 files changed, 11 insertions(+), 4 deletions(-)