Commit 9300d8df authored by Joonsoo Kim's avatar Joonsoo Kim Committed by Linus Torvalds
Browse files

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: default avatarJoonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 980ac167

include/linux/page_ext.h

+0 −6
Original line number Diff line number Diff line
@@ -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);

mm/page_owner.c

+58 −25
Original line number Diff line number Diff line
@@ -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;

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