| Message ID | a5341defeef27c9ac7b85c97f030f93e4368bbc1.1711694852.git.baolin.wang@linux.alibaba.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm: huge_memory: add the missing folio_test_pmd_mappable() for THP split statistics | expand |
Hey Baolin, Maybe I spotted a bug and made a change to this patch as follows. diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 824eff9211db..f3c4e08c6d30 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2994,6 +2994,7 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list, XA_STATE_ORDER(xas, &folio->mapping->i_pages, folio->index, new_order); struct anon_vma *anon_vma = NULL; struct address_space *mapping = NULL; + int order = folio_order(folio); int extra_pins, ret; pgoff_t end; bool is_hzp; @@ -3172,7 +3173,7 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list, i_mmap_unlock_read(mapping); out: xas_destroy(&xas); - if (folio_test_pmd_mappable(folio)) IIUC, if we split the folio successfully, it won’t be large here. + if (order >= HPAGE_PMD_ORDER) count_vm_event(!ret ? THP_SPLIT_PAGE : THP_SPLIT_PAGE_FAILED); return ret; } Thanks, Lance
On 2024/4/22 14:17, Lance Yang wrote: > Hey Baolin, > > Maybe I spotted a bug and made a change to this patch as follows. > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index 824eff9211db..f3c4e08c6d30 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -2994,6 +2994,7 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list, > XA_STATE_ORDER(xas, &folio->mapping->i_pages, folio->index, new_order); > struct anon_vma *anon_vma = NULL; > struct address_space *mapping = NULL; > + int order = folio_order(folio); > int extra_pins, ret; > pgoff_t end; > bool is_hzp; > @@ -3172,7 +3173,7 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list, > i_mmap_unlock_read(mapping); > out: > xas_destroy(&xas); > - if (folio_test_pmd_mappable(folio)) > > IIUC, if we split the folio successfully, it won’t be large here. Yes, good catch. I did a blindly copy-paste. Will fix in next version. Thanks for reviewing. > + if (order >= HPAGE_PMD_ORDER) > count_vm_event(!ret ? THP_SPLIT_PAGE : THP_SPLIT_PAGE_FAILED); > return ret; > } > > Thanks, > Lance
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 1683de78c313..3ca9282a0dc9 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -3109,7 +3109,8 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list, i_mmap_unlock_read(mapping); out: xas_destroy(&xas); - count_vm_event(!ret ? THP_SPLIT_PAGE : THP_SPLIT_PAGE_FAILED); + if (folio_test_pmd_mappable(folio)) + count_vm_event(!ret ? THP_SPLIT_PAGE : THP_SPLIT_PAGE_FAILED); return ret; } @@ -3171,7 +3172,8 @@ void deferred_split_folio(struct folio *folio) spin_lock_irqsave(&ds_queue->split_queue_lock, flags); if (list_empty(&folio->_deferred_list)) { - count_vm_event(THP_DEFERRED_SPLIT_PAGE); + if (folio_test_pmd_mappable(folio)) + count_vm_event(THP_DEFERRED_SPLIT_PAGE); list_add_tail(&folio->_deferred_list, &ds_queue->split_queue); ds_queue->split_queue_len++; #ifdef CONFIG_MEMCG
Now the mTHP can also be split or added into the deferred list, so add folio_test_pmd_mappable() validation for PMD mapped THP, to avoid confusion with PMD mapped THP related statistics. Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> --- mm/huge_memory.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)