This patch adds basic functionality to put huge page into page cache. At the moment we only put huge pages into radix-tree if the range covered by the huge page is empty. Handling of shadow entires will be added later.
Signed-off-by: Kirill A. Shutemov <[email protected]> --- include/linux/fs.h | 5 +++ include/linux/pagemap.h | 21 +++++++-- mm/filemap.c | 113 ++++++++++++++++++++++++++++++++++++++++++------ 3 files changed, 122 insertions(+), 17 deletions(-) diff --git a/include/linux/fs.h b/include/linux/fs.h index b7c9198d3f54..0208b41d8de2 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1861,6 +1861,11 @@ struct super_operations { #else #define S_DAX 0 /* Make all the DAX code disappear */ #endif +#define S_HUGE_MODE 0xc000 +#define S_HUGE_NEVER 0x0000 +#define S_HUGE_ALWAYS 0x4000 +#define S_HUGE_WITHIN_SIZE 0x8000 +#define S_HUGE_ADVISE 0xc000 /* * Note that nosuid etc flags are inode-specific: setting some file-system diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 81363b834900..d9cf4e0f35dc 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -191,14 +191,20 @@ static inline int page_cache_add_speculative(struct page *page, int count) } #ifdef CONFIG_NUMA -extern struct page *__page_cache_alloc(gfp_t gfp); +extern struct page *__page_cache_alloc_order(gfp_t gfp, unsigned int order); #else -static inline struct page *__page_cache_alloc(gfp_t gfp) +static inline struct page *__page_cache_alloc_order(gfp_t gfp, + unsigned int order) { - return alloc_pages(gfp, 0); + return alloc_pages(gfp, order); } #endif +static inline struct page *__page_cache_alloc(gfp_t gfp) +{ + return __page_cache_alloc_order(gfp, 0); +} + static inline struct page *page_cache_alloc(struct address_space *x) { return __page_cache_alloc(mapping_gfp_mask(x)); @@ -215,6 +221,15 @@ static inline gfp_t readahead_gfp_mask(struct address_space *x) __GFP_COLD | __GFP_NORETRY | __GFP_NOWARN; } +extern bool __page_cache_allow_huge(struct address_space *x, pgoff_t offset); +static inline bool page_cache_allow_huge(struct address_space *x, + pgoff_t offset) +{ + if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) + return false; + return __page_cache_allow_huge(x, offset); +} + typedef int filler_t(void *, struct page *); pgoff_t page_cache_next_hole(struct address_space *mapping, diff --git a/mm/filemap.c b/mm/filemap.c index 7daedd910cf4..a3183e688718 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -636,14 +636,14 @@ static int __add_to_page_cache_locked(struct page *page, pgoff_t offset, gfp_t gfp_mask, void **shadowp) { - int huge = PageHuge(page); + int hugetlb = PageHuge(page); struct mem_cgroup *memcg; int error; VM_BUG_ON_PAGE(!PageLocked(page), page); VM_BUG_ON_PAGE(PageSwapBacked(page), page); - if (!huge) { + if (!hugetlb) { error = mem_cgroup_try_charge(page, current->mm, gfp_mask, &memcg, false); if (error) @@ -652,7 +652,7 @@ static int __add_to_page_cache_locked(struct page *page, error = radix_tree_maybe_preload(gfp_mask & ~__GFP_HIGHMEM); if (error) { - if (!huge) + if (!hugetlb) mem_cgroup_cancel_charge(page, memcg, false); return error; } @@ -662,16 +662,30 @@ static int __add_to_page_cache_locked(struct page *page, page->index = offset; spin_lock_irq(&mapping->tree_lock); - error = page_cache_tree_insert(mapping, page, shadowp); + if (PageTransHuge(page)) { + /* TODO: shadow handling */ + error = __radix_tree_insert(&mapping->page_tree, offset, + compound_order(page), page); + + if (!error) { + count_vm_event(THP_FILE_ALLOC); + mapping->nrpages += HPAGE_PMD_NR; + *shadowp = NULL; + __inc_node_page_state(page, NR_FILE_THPS); + } + } else { + error = page_cache_tree_insert(mapping, page, shadowp); + } radix_tree_preload_end(); if (unlikely(error)) goto err_insert; /* hugetlb pages do not participate in page cache accounting. */ - if (!huge) - __inc_node_page_state(page, NR_FILE_PAGES); + if (!hugetlb) + __mod_node_page_state(page_pgdat(page), NR_FILE_PAGES, + hpage_nr_pages(page)); spin_unlock_irq(&mapping->tree_lock); - if (!huge) + if (!hugetlb) mem_cgroup_commit_charge(page, memcg, false, false); trace_mm_filemap_add_to_page_cache(page); return 0; @@ -679,7 +693,7 @@ err_insert: page->mapping = NULL; /* Leave page->index set: truncation relies upon it */ spin_unlock_irq(&mapping->tree_lock); - if (!huge) + if (!hugetlb) mem_cgroup_cancel_charge(page, memcg, false); put_page(page); return error; @@ -736,7 +750,7 @@ int add_to_page_cache_lru(struct page *page, struct address_space *mapping, EXPORT_SYMBOL_GPL(add_to_page_cache_lru); #ifdef CONFIG_NUMA -struct page *__page_cache_alloc(gfp_t gfp) +struct page *__page_cache_alloc_order(gfp_t gfp, unsigned int order) { int n; struct page *page; @@ -746,14 +760,14 @@ struct page *__page_cache_alloc(gfp_t gfp) do { cpuset_mems_cookie = read_mems_allowed_begin(); n = cpuset_mem_spread_node(); - page = __alloc_pages_node(n, gfp, 0); + page = __alloc_pages_node(n, gfp, order); } while (!page && read_mems_allowed_retry(cpuset_mems_cookie)); return page; } - return alloc_pages(gfp, 0); + return alloc_pages(gfp, order); } -EXPORT_SYMBOL(__page_cache_alloc); +EXPORT_SYMBOL(__page_cache_alloc_order); #endif /* @@ -1148,6 +1162,59 @@ repeat: } EXPORT_SYMBOL(find_lock_entry); +bool __page_cache_allow_huge(struct address_space *mapping, pgoff_t offset) +{ + struct inode *inode = mapping->host; + void __rcu **results; + unsigned long idx; + + offset = round_down(offset, HPAGE_PMD_NR); + + switch (inode->i_flags & S_HUGE_MODE) { + case S_HUGE_NEVER: + return false; + case S_HUGE_ALWAYS: + break; + case S_HUGE_WITHIN_SIZE: + if (DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE) < + offset + HPAGE_PMD_NR) + return false; + break; + case S_HUGE_ADVISE: + /* TODO */ + return false; + default: + WARN_ON_ONCE(1); + return false; + } + + rcu_read_lock(); + if (radix_tree_gang_lookup_slot(&mapping->page_tree, &results, &idx, + offset, 1) && idx < offset + HPAGE_PMD_NR) { + rcu_read_unlock(); + return false; + } + rcu_read_unlock(); + + return true; + +} + +static struct page *page_cache_alloc_huge(struct address_space *mapping, + pgoff_t offset, gfp_t gfp_mask) +{ + struct page *page; + + if (!page_cache_allow_huge(mapping, offset)) + return NULL; + + gfp_mask |= __GFP_COMP | __GFP_NORETRY | __GFP_NOWARN; + page = __page_cache_alloc_order(gfp_mask, HPAGE_PMD_ORDER); + if (page) + prep_transhuge_page(page); + return page; +} + /** * pagecache_get_page - find and get a page reference * @mapping: the address_space to search @@ -2016,19 +2083,37 @@ static int page_cache_read(struct file *file, pgoff_t offset, gfp_t gfp_mask) { struct address_space *mapping = file->f_mapping; struct page *page; + pgoff_t hoffset; int ret; do { - page = __page_cache_alloc(gfp_mask|__GFP_COLD); + page = page_cache_alloc_huge(mapping, offset, gfp_mask); +no_huge: + if (!page) + page = __page_cache_alloc(gfp_mask|__GFP_COLD); if (!page) return -ENOMEM; - ret = add_to_page_cache_lru(page, mapping, offset, gfp_mask & GFP_KERNEL); + if (PageTransHuge(page)) + hoffset = round_down(offset, HPAGE_PMD_NR); + else + hoffset = offset; + + ret = add_to_page_cache_lru(page, mapping, hoffset, + gfp_mask & GFP_KERNEL); if (ret == 0) ret = mapping->a_ops->readpage(file, page); else if (ret == -EEXIST) ret = 0; /* losing race to add is OK */ + if (ret && PageTransHuge(page)) { + delete_from_page_cache(page); + unlock_page(page); + put_page(page); + page = NULL; + goto no_huge; + } + put_page(page); } while (ret == AOP_TRUNCATED_PAGE); -- 2.8.1 -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
