From: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Subject: mm/page_owner: don't define fields on struct page_ext by hard-coding There is a memory waste problem if we define field on struct page_ext by hard-coding. Entry size of struct page_ext includes the size of those fields even if it is disabled at runtime. Now, extra memory request at runtime is possible so page_owner don't need to define it's own fields by hard-coding. This patch removes hard-coded define and uses extra memory for storing page_owner information in page_owner. Most of code are just mechanical changes. Link: http://lkml.kernel.org/r/1471315879-32294-7-git-send-email-iamjoonsoo.kim@xxxxxxx Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Acked-by: Vlastimil Babka <vbabka@xxxxxxx> Cc: Minchan Kim <minchan@xxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxxxx> Cc: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/page_ext.h | 6 -- mm/page_owner.c | 83 +++++++++++++++++++++++++------------ 2 files changed, 58 insertions(+), 31 deletions(-) diff -puN include/linux/page_ext.h~mm-page_owner-dont-define-fields-on-struct-page_ext-by-hard-coding include/linux/page_ext.h --- a/include/linux/page_ext.h~mm-page_owner-dont-define-fields-on-struct-page_ext-by-hard-coding +++ a/include/linux/page_ext.h @@ -44,12 +44,6 @@ enum page_ext_flags { */ struct page_ext { unsigned long flags; -#ifdef CONFIG_PAGE_OWNER - unsigned int order; - gfp_t gfp_mask; - int last_migrate_reason; - depot_stack_handle_t handle; -#endif }; extern void pgdat_page_ext_init(struct pglist_data *pgdat); diff -puN mm/page_owner.c~mm-page_owner-dont-define-fields-on-struct-page_ext-by-hard-coding mm/page_owner.c --- a/mm/page_owner.c~mm-page_owner-dont-define-fields-on-struct-page_ext-by-hard-coding +++ a/mm/page_owner.c @@ -18,6 +18,13 @@ */ #define PAGE_OWNER_STACK_DEPTH (16) +struct page_owner { + unsigned int order; + gfp_t gfp_mask; + int last_migrate_reason; + depot_stack_handle_t handle; +}; + static bool page_owner_disabled = true; DEFINE_STATIC_KEY_FALSE(page_owner_inited); @@ -86,10 +93,16 @@ static void init_page_owner(void) } struct page_ext_operations page_owner_ops = { + .size = sizeof(struct page_owner), .need = need_page_owner, .init = init_page_owner, }; +static inline struct page_owner *get_page_owner(struct page_ext *page_ext) +{ + return (void *)page_ext + page_owner_ops.offset; +} + void __reset_page_owner(struct page *page, unsigned int order) { int i; @@ -156,14 +169,16 @@ noinline void __set_page_owner(struct pa gfp_t gfp_mask) { struct page_ext *page_ext = lookup_page_ext(page); + struct page_owner *page_owner; if (unlikely(!page_ext)) return; - page_ext->handle = save_stack(gfp_mask); - page_ext->order = order; - page_ext->gfp_mask = gfp_mask; - page_ext->last_migrate_reason = -1; + page_owner = get_page_owner(page_ext); + page_owner->handle = save_stack(gfp_mask); + page_owner->order = order; + page_owner->gfp_mask = gfp_mask; + page_owner->last_migrate_reason = -1; __set_bit(PAGE_EXT_OWNER, &page_ext->flags); } @@ -171,21 +186,26 @@ noinline void __set_page_owner(struct pa void __set_page_owner_migrate_reason(struct page *page, int reason) { struct page_ext *page_ext = lookup_page_ext(page); + struct page_owner *page_owner; + if (unlikely(!page_ext)) return; - page_ext->last_migrate_reason = reason; + page_owner = get_page_owner(page_ext); + page_owner->last_migrate_reason = reason; } void __split_page_owner(struct page *page, unsigned int order) { int i; struct page_ext *page_ext = lookup_page_ext(page); + struct page_owner *page_owner; if (unlikely(!page_ext)) return; - page_ext->order = 0; + page_owner = get_page_owner(page_ext); + page_owner->order = 0; for (i = 1; i < (1 << order); i++) __copy_page_owner(page, page + i); } @@ -194,14 +214,18 @@ void __copy_page_owner(struct page *oldp { struct page_ext *old_ext = lookup_page_ext(oldpage); struct page_ext *new_ext = lookup_page_ext(newpage); + struct page_owner *old_page_owner, *new_page_owner; if (unlikely(!old_ext || !new_ext)) return; - new_ext->order = old_ext->order; - new_ext->gfp_mask = old_ext->gfp_mask; - new_ext->last_migrate_reason = old_ext->last_migrate_reason; - new_ext->handle = old_ext->handle; + old_page_owner = get_page_owner(old_ext); + new_page_owner = get_page_owner(new_ext); + new_page_owner->order = old_page_owner->order; + new_page_owner->gfp_mask = old_page_owner->gfp_mask; + new_page_owner->last_migrate_reason = + old_page_owner->last_migrate_reason; + new_page_owner->handle = old_page_owner->handle; /* * We don't clear the bit on the oldpage as it's going to be freed @@ -220,6 +244,7 @@ void pagetypeinfo_showmixedcount_print(s { struct page *page; struct page_ext *page_ext; + struct page_owner *page_owner; unsigned long pfn = zone->zone_start_pfn, block_end_pfn; unsigned long end_pfn = pfn + zone->spanned_pages; unsigned long count[MIGRATE_TYPES] = { 0, }; @@ -270,7 +295,9 @@ void pagetypeinfo_showmixedcount_print(s if (!test_bit(PAGE_EXT_OWNER, &page_ext->flags)) continue; - page_mt = gfpflags_to_migratetype(page_ext->gfp_mask); + page_owner = get_page_owner(page_ext); + page_mt = gfpflags_to_migratetype( + page_owner->gfp_mask); if (pageblock_mt != page_mt) { if (is_migrate_cma(pageblock_mt)) count[MIGRATE_MOVABLE]++; @@ -280,7 +307,7 @@ void pagetypeinfo_showmixedcount_print(s pfn = block_end_pfn; break; } - pfn += (1UL << page_ext->order) - 1; + pfn += (1UL << page_owner->order) - 1; } } @@ -293,7 +320,7 @@ void pagetypeinfo_showmixedcount_print(s static ssize_t print_page_owner(char __user *buf, size_t count, unsigned long pfn, - struct page *page, struct page_ext *page_ext, + struct page *page, struct page_owner *page_owner, depot_stack_handle_t handle) { int ret; @@ -313,15 +340,15 @@ print_page_owner(char __user *buf, size_ ret = snprintf(kbuf, count, "Page allocated via order %u, mask %#x(%pGg)\n", - page_ext->order, page_ext->gfp_mask, - &page_ext->gfp_mask); + page_owner->order, page_owner->gfp_mask, + &page_owner->gfp_mask); if (ret >= count) goto err; /* Print information relevant to grouping pages by mobility */ pageblock_mt = get_pageblock_migratetype(page); - page_mt = gfpflags_to_migratetype(page_ext->gfp_mask); + page_mt = gfpflags_to_migratetype(page_owner->gfp_mask); ret += snprintf(kbuf + ret, count - ret, "PFN %lu type %s Block %lu type %s Flags %#lx(%pGp)\n", pfn, @@ -338,10 +365,10 @@ print_page_owner(char __user *buf, size_ if (ret >= count) goto err; - if (page_ext->last_migrate_reason != -1) { + if (page_owner->last_migrate_reason != -1) { ret += snprintf(kbuf + ret, count - ret, "Page has been migrated, last migrate reason: %s\n", - migrate_reason_names[page_ext->last_migrate_reason]); + migrate_reason_names[page_owner->last_migrate_reason]); if (ret >= count) goto err; } @@ -364,6 +391,7 @@ err: void __dump_page_owner(struct page *page) { struct page_ext *page_ext = lookup_page_ext(page); + struct page_owner *page_owner; unsigned long entries[PAGE_OWNER_STACK_DEPTH]; struct stack_trace trace = { .nr_entries = 0, @@ -379,7 +407,9 @@ void __dump_page_owner(struct page *page pr_alert("There is not page extension available.\n"); return; } - gfp_mask = page_ext->gfp_mask; + + page_owner = get_page_owner(page_ext); + gfp_mask = page_owner->gfp_mask; mt = gfpflags_to_migratetype(gfp_mask); if (!test_bit(PAGE_EXT_OWNER, &page_ext->flags)) { @@ -387,7 +417,7 @@ void __dump_page_owner(struct page *page return; } - handle = READ_ONCE(page_ext->handle); + handle = READ_ONCE(page_owner->handle); if (!handle) { pr_alert("page_owner info is not active (free page?)\n"); return; @@ -395,12 +425,12 @@ void __dump_page_owner(struct page *page depot_fetch_stack(handle, &trace); pr_alert("page allocated via order %u, migratetype %s, gfp_mask %#x(%pGg)\n", - page_ext->order, migratetype_names[mt], gfp_mask, &gfp_mask); + page_owner->order, migratetype_names[mt], gfp_mask, &gfp_mask); print_stack_trace(&trace, 0); - if (page_ext->last_migrate_reason != -1) + if (page_owner->last_migrate_reason != -1) pr_alert("page has been migrated, last migrate reason: %s\n", - migrate_reason_names[page_ext->last_migrate_reason]); + migrate_reason_names[page_owner->last_migrate_reason]); } static ssize_t @@ -409,6 +439,7 @@ read_page_owner(struct file *file, char unsigned long pfn; struct page *page; struct page_ext *page_ext; + struct page_owner *page_owner; depot_stack_handle_t handle; if (!static_branch_unlikely(&page_owner_inited)) @@ -458,11 +489,13 @@ read_page_owner(struct file *file, char if (!test_bit(PAGE_EXT_OWNER, &page_ext->flags)) continue; + page_owner = get_page_owner(page_ext); + /* * Access to page_ext->handle isn't synchronous so we should * be careful to access it. */ - handle = READ_ONCE(page_ext->handle); + handle = READ_ONCE(page_owner->handle); if (!handle) continue; @@ -470,7 +503,7 @@ read_page_owner(struct file *file, char *ppos = (pfn - min_low_pfn) + 1; return print_page_owner(buf, count, pfn, page, - page_ext, handle); + page_owner, handle); } return 0; _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
