Messages in this thread | | | Date | Tue, 25 Aug 2015 16:03:22 +0200 | From | Michal Hocko <> | Subject | Re: [PATCH v2] mm/page_alloc: add a helper function to check page before alloc/free |
| |
On Tue 25-08-15 21:26:30, Yaowei Bai wrote: [...] > static inline int check_new_page(struct page *page) > { > - const char *bad_reason = NULL; > - unsigned long bad_flags = 0; > - > - if (unlikely(page_mapcount(page))) > - bad_reason = "nonzero mapcount"; > - if (unlikely(page->mapping != NULL)) > - bad_reason = "non-NULL mapping"; > - if (unlikely(atomic_read(&page->_count) != 0)) > - bad_reason = "nonzero _count"; > - if (unlikely(page->flags & __PG_HWPOISON)) { > - bad_reason = "HWPoisoned (hardware-corrupted)"; > - bad_flags = __PG_HWPOISON; > - }
You have removed this check AFAICS. Now looking at 39ad4f19671d ("mm: check __PG_HWPOISON separately from PAGE_FLAGS_CHECK_AT_*") I am not sure it is correct to check it in the free path as it was removed from the mask by this commit.
> - if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_PREP)) { > - bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag set"; > - bad_flags = PAGE_FLAGS_CHECK_AT_PREP; > - } > -#ifdef CONFIG_MEMCG > - if (unlikely(page->mem_cgroup)) > - bad_reason = "page still charged to cgroup"; > -#endif > - if (unlikely(bad_reason)) { > - bad_page(page, bad_reason, bad_flags); > - return 1; > - } > - return 0; > + return check_one_page(page, PAGE_FLAGS_CHECK_AT_PREP); > } > > static int prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags, > -- > 1.9.1 >
-- Michal Hocko SUSE Labs
| |