| Message ID | 20230922193639.10158-2-vishal.moola@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Remove compound_pagelist from khugepaged | expand |
On Fri, Sep 22, 2023 at 12:36:38PM -0700, Vishal Moola (Oracle) wrote: > This is in preparation for the removal of the khugepaged compound_pagelist. > > Replaces 11 calls to compound_head() with 1, and removes 499 bytes of > kernel text. Looks good to me. > @@ -634,32 +633,33 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma, > * Isolate the page to avoid collapsing an hugepage > * currently in use by the VM. > */ > - if (!isolate_lru_page(page)) { > - unlock_page(page); > + if (!folio_isolate_lru(folio)) { > + folio_unlock(folio); > result = SCAN_DEL_PAGE_LRU; > goto out; > } > - mod_node_page_state(page_pgdat(page), > - NR_ISOLATED_ANON + page_is_file_lru(page), > - compound_nr(page)); > - VM_BUG_ON_PAGE(!PageLocked(page), page); > - VM_BUG_ON_PAGE(PageLRU(page), page); > + node_stat_mod_folio(folio, > + NR_ISOLATED_ANON + folio_is_file_lru(folio), > + folio_nr_pages(folio)); > + VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio); > + VM_BUG_ON_FOLIO(folio_test_lru(folio), folio); > > - if (PageCompound(page)) > - list_add_tail(&page->lru, compound_pagelist); > + if (folio_test_large(folio)) > + list_add_tail(&folio->lru, compound_pagelist); > next: > /* > * If collapse was initiated by khugepaged, check that there is > * enough young pte to justify collapsing the page > */ > if (cc->is_khugepaged && > - (pte_young(pteval) || page_is_young(page) || > - PageReferenced(page) || mmu_notifier_test_young(vma->vm_mm, > + (pte_young(pteval) || folio_test_young(folio) || > + folio_test_referenced(folio) || mmu_notifier_test_young(vma->vm_mm, > address))) > referenced++; > > if (pte_write(pteval)) > writable = true; > + Spurious change here. Other than that, Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
On 22.09.23 21:36, Vishal Moola (Oracle) wrote: > This is in preparation for the removal of the khugepaged compound_pagelist. > > Replaces 11 calls to compound_head() with 1, and removes 499 bytes of > kernel text. > > Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> > --- > mm/khugepaged.c | 52 ++++++++++++++++++++++++------------------------- > 1 file changed, 26 insertions(+), 26 deletions(-) > > diff --git a/mm/khugepaged.c b/mm/khugepaged.c > index 88433cc25d8a..f46a7a7c489f 100644 > --- a/mm/khugepaged.c > +++ b/mm/khugepaged.c > @@ -541,7 +541,7 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma, > struct collapse_control *cc, > struct list_head *compound_pagelist) > { > - struct page *page = NULL; > + struct folio *folio = NULL; > pte_t *_pte; > int none_or_zero = 0, shared = 0, result = SCAN_FAIL, referenced = 0; > bool writable = false; > @@ -570,15 +570,15 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma, > result = SCAN_PTE_UFFD_WP; > goto out; > } > - page = vm_normal_page(vma, address, pteval); > - if (unlikely(!page) || unlikely(is_zone_device_page(page))) { > + folio = vm_normal_folio(vma, address, pteval); > + if (unlikely(!folio) || unlikely(folio_is_zone_device(folio))) { > result = SCAN_PAGE_NULL; > goto out; > } > > - VM_BUG_ON_PAGE(!PageAnon(page), page); > + VM_BUG_ON_FOLIO(!folio_test_anon(folio), folio); > > - if (page_mapcount(page) > 1) { > + if (folio_estimated_sharers(folio) > 1) { For a tail page of a PTE-mapped THP this is not the same. The possible side effects this might have should be spelled out in the patch description.
On Mon, Sep 25, 2023 at 12:18 AM David Hildenbrand <david@redhat.com> wrote: > > On 22.09.23 21:36, Vishal Moola (Oracle) wrote: > > This is in preparation for the removal of the khugepaged compound_pagelist. > > > > Replaces 11 calls to compound_head() with 1, and removes 499 bytes of > > kernel text. > > > > Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> > > --- > > mm/khugepaged.c | 52 ++++++++++++++++++++++++------------------------- > > 1 file changed, 26 insertions(+), 26 deletions(-) > > > > diff --git a/mm/khugepaged.c b/mm/khugepaged.c > > index 88433cc25d8a..f46a7a7c489f 100644 > > --- a/mm/khugepaged.c > > +++ b/mm/khugepaged.c > > @@ -541,7 +541,7 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma, > > struct collapse_control *cc, > > struct list_head *compound_pagelist) > > { > > - struct page *page = NULL; > > + struct folio *folio = NULL; > > pte_t *_pte; > > int none_or_zero = 0, shared = 0, result = SCAN_FAIL, referenced = 0; > > bool writable = false; > > @@ -570,15 +570,15 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma, > > result = SCAN_PTE_UFFD_WP; > > goto out; > > } > > - page = vm_normal_page(vma, address, pteval); > > - if (unlikely(!page) || unlikely(is_zone_device_page(page))) { > > + folio = vm_normal_folio(vma, address, pteval); > > + if (unlikely(!folio) || unlikely(folio_is_zone_device(folio))) { > > result = SCAN_PAGE_NULL; > > goto out; > > } > > > > - VM_BUG_ON_PAGE(!PageAnon(page), page); > > + VM_BUG_ON_FOLIO(!folio_test_anon(folio), folio); > > > > - if (page_mapcount(page) > 1) { > > + if (folio_estimated_sharers(folio) > 1) { > > For a tail page of a PTE-mapped THP this is not the same. > > The possible side effects this might have should be spelled out in the > patch description. Ok, I'll add the side effects to the commit message in v2.
diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 88433cc25d8a..f46a7a7c489f 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -541,7 +541,7 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma, struct collapse_control *cc, struct list_head *compound_pagelist) { - struct page *page = NULL; + struct folio *folio = NULL; pte_t *_pte; int none_or_zero = 0, shared = 0, result = SCAN_FAIL, referenced = 0; bool writable = false; @@ -570,15 +570,15 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma, result = SCAN_PTE_UFFD_WP; goto out; } - page = vm_normal_page(vma, address, pteval); - if (unlikely(!page) || unlikely(is_zone_device_page(page))) { + folio = vm_normal_folio(vma, address, pteval); + if (unlikely(!folio) || unlikely(folio_is_zone_device(folio))) { result = SCAN_PAGE_NULL; goto out; } - VM_BUG_ON_PAGE(!PageAnon(page), page); + VM_BUG_ON_FOLIO(!folio_test_anon(folio), folio); - if (page_mapcount(page) > 1) { + if (folio_estimated_sharers(folio) > 1) { ++shared; if (cc->is_khugepaged && shared > khugepaged_max_ptes_shared) { @@ -588,16 +588,15 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma, } } - if (PageCompound(page)) { - struct page *p; - page = compound_head(page); + if (folio_test_large(folio)) { + struct folio *f; /* * Check if we have dealt with the compound page * already */ - list_for_each_entry(p, compound_pagelist, lru) { - if (page == p) + list_for_each_entry(f, compound_pagelist, lru) { + if (folio == f) goto next; } } @@ -608,7 +607,7 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma, * is needed to serialize against split_huge_page * when invoked from the VM. */ - if (!trylock_page(page)) { + if (!folio_trylock(folio)) { result = SCAN_PAGE_LOCK; goto out; } @@ -624,8 +623,8 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma, * but not from this process. The other process cannot write to * the page, only trigger CoW. */ - if (!is_refcount_suitable(page)) { - unlock_page(page); + if (!is_refcount_suitable(&folio->page)) { + folio_unlock(folio); result = SCAN_PAGE_COUNT; goto out; } @@ -634,32 +633,33 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma, * Isolate the page to avoid collapsing an hugepage * currently in use by the VM. */ - if (!isolate_lru_page(page)) { - unlock_page(page); + if (!folio_isolate_lru(folio)) { + folio_unlock(folio); result = SCAN_DEL_PAGE_LRU; goto out; } - mod_node_page_state(page_pgdat(page), - NR_ISOLATED_ANON + page_is_file_lru(page), - compound_nr(page)); - VM_BUG_ON_PAGE(!PageLocked(page), page); - VM_BUG_ON_PAGE(PageLRU(page), page); + node_stat_mod_folio(folio, + NR_ISOLATED_ANON + folio_is_file_lru(folio), + folio_nr_pages(folio)); + VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio); + VM_BUG_ON_FOLIO(folio_test_lru(folio), folio); - if (PageCompound(page)) - list_add_tail(&page->lru, compound_pagelist); + if (folio_test_large(folio)) + list_add_tail(&folio->lru, compound_pagelist); next: /* * If collapse was initiated by khugepaged, check that there is * enough young pte to justify collapsing the page */ if (cc->is_khugepaged && - (pte_young(pteval) || page_is_young(page) || - PageReferenced(page) || mmu_notifier_test_young(vma->vm_mm, + (pte_young(pteval) || folio_test_young(folio) || + folio_test_referenced(folio) || mmu_notifier_test_young(vma->vm_mm, address))) referenced++; if (pte_write(pteval)) writable = true; + } if (unlikely(!writable)) { @@ -668,13 +668,13 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma, result = SCAN_LACK_REFERENCED_PAGE; } else { result = SCAN_SUCCEED; - trace_mm_collapse_huge_page_isolate(page, none_or_zero, + trace_mm_collapse_huge_page_isolate(&folio->page, none_or_zero, referenced, writable, result); return result; } out: release_pte_pages(pte, _pte, compound_pagelist); - trace_mm_collapse_huge_page_isolate(page, none_or_zero, + trace_mm_collapse_huge_page_isolate(&folio->page, none_or_zero, referenced, writable, result); return result; }
This is in preparation for the removal of the khugepaged compound_pagelist. Replaces 11 calls to compound_head() with 1, and removes 499 bytes of kernel text. Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> --- mm/khugepaged.c | 52 ++++++++++++++++++++++++------------------------- 1 file changed, 26 insertions(+), 26 deletions(-)