From 980ac1672e7edaa927557a5186f1967cd45afcf5 Mon Sep 17 00:00:00 2001 From: Joonsoo Kim Date: Fri, 7 Oct 2016 16:58:27 -0700 Subject: mm/page_ext: support extra space allocation by page_ext user Until now, if some page_ext users want to use it's own field on page_ext, it should be defined in struct page_ext by hard-coding. It has a problem that wastes memory in following situation. struct page_ext { #ifdef CONFIG_A int a; #endif #ifdef CONFIG_B int b; #endif }; Assume that kernel is built with both CONFIG_A and CONFIG_B. Even if we enable feature A and doesn't enable feature B at runtime, each entry of struct page_ext takes two int rather than one int. It's undesirable result so this patch tries to fix it. To solve above problem, this patch implements to support extra space allocation at runtime. When need() callback returns true, it's extra memory requirement is summed to entry size of page_ext. Also, offset for each user's extra memory space is returned. With this offset, user can use this extra space and there is no need to define needed field on page_ext by hard-coding. This patch only implements an infrastructure. Following patch will use it for page_owner which is only user having it's own fields on page_ext. Link: http://lkml.kernel.org/r/1471315879-32294-6-git-send-email-iamjoonsoo.kim@lge.com Signed-off-by: Joonsoo Kim Acked-by: Vlastimil Babka Cc: Minchan Kim Cc: Michal Hocko Cc: Sergey Senozhatsky Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/page_ext.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/page_ext.h') diff --git a/include/linux/page_ext.h b/include/linux/page_ext.h index 03f2a3e7d76d..179bdc4a470c 100644 --- a/include/linux/page_ext.h +++ b/include/linux/page_ext.h @@ -7,6 +7,8 @@ struct pglist_data; struct page_ext_operations { + size_t offset; + size_t size; bool (*need)(void); void (*init)(void); }; -- cgit v1.2.3 From 9300d8dfd282bd1473395c5c4c76bfdc90b05978 Mon Sep 17 00:00:00 2001 From: Joonsoo Kim Date: Fri, 7 Oct 2016 16:58:30 -0700 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@lge.com Signed-off-by: Joonsoo Kim Acked-by: Vlastimil Babka Cc: Minchan Kim Cc: Michal Hocko Cc: Sergey Senozhatsky Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/page_ext.h | 6 ---- mm/page_owner.c | 83 +++++++++++++++++++++++++++++++++--------------- 2 files changed, 58 insertions(+), 31 deletions(-) (limited to 'include/linux/page_ext.h') diff --git a/include/linux/page_ext.h b/include/linux/page_ext.h index 179bdc4a470c..9298c393ddaa 100644 --- a/include/linux/page_ext.h +++ b/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 --git a/mm/page_owner.c b/mm/page_owner.c index 0f4246d109a0..60634dc53a88 100644 --- a/mm/page_owner.c +++ b/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 page *page, unsigned int order, 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 page *page, unsigned int order, 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 *oldpage, struct page *newpage) { 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(struct seq_file *m, { 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(struct seq_file *m, 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(struct seq_file *m, 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(struct seq_file *m, 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_t count, unsigned long pfn, 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_t count, unsigned long pfn, 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 __user *buf, size_t count, loff_t *ppos) 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 __user *buf, size_t count, loff_t *ppos) 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 __user *buf, size_t count, loff_t *ppos) *ppos = (pfn - min_low_pfn) + 1; return print_page_owner(buf, count, pfn, page, - page_ext, handle); + page_owner, handle); } return 0; -- cgit v1.2.3