Commit 3f9903b9 authored by David Hildenbrand's avatar David Hildenbrand Committed by Linus Torvalds
Browse files

mm: remove the memory isolate notifier 

Luckily, we have no users left, so we can get rid of it.  Cleanup
set_migratetype_isolate() a little bit.

Link: http://lkml.kernel.org/r/20191114131911.11783-2-david@redhat.com


Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
Reviewed-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Qian Cai <cai@lca.pw>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Pingfan Liu <kernelfans@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 3f135355

drivers/base/memory.c

+0 −19
Original line number Diff line number Diff line
@@ -70,20 +70,6 @@ void unregister_memory_notifier(struct notifier_block *nb) 
}

EXPORT_SYMBOL(unregister_memory_notifier);



static ATOMIC_NOTIFIER_HEAD(memory_isolate_chain);



int register_memory_isolate_notifier(struct notifier_block *nb)

{

	return atomic_notifier_chain_register(&memory_isolate_chain, nb);

}

EXPORT_SYMBOL(register_memory_isolate_notifier);



void unregister_memory_isolate_notifier(struct notifier_block *nb)

{

	atomic_notifier_chain_unregister(&memory_isolate_chain, nb);

}

EXPORT_SYMBOL(unregister_memory_isolate_notifier);



static void memory_block_release(struct device *dev)

{

	struct memory_block *mem = to_memory_block(dev);
@@ -175,11 +161,6 @@ int memory_notify(unsigned long val, void *v) 
	return blocking_notifier_call_chain(&memory_chain, val, v);

}



int memory_isolate_notify(unsigned long val, void *v)

{

	return atomic_notifier_call_chain(&memory_isolate_chain, val, v);

}



/*

 * The probe routines leave the pages uninitialized, just as the bootmem code

 * does. Make sure we do not access them, but instead use only information from

include/linux/memory.h

+0 −27
Original line number Diff line number Diff line
@@ -55,19 +55,6 @@ struct memory_notify { 
	int status_change_nid;

};



/*

 * During pageblock isolation, count the number of pages within the

 * range [start_pfn, start_pfn + nr_pages) which are owned by code

 * in the notifier chain.

 */

#define MEM_ISOLATE_COUNT	(1<<0)



struct memory_isolate_notify {

	unsigned long start_pfn;	/* Start of range to check */

	unsigned int nr_pages;		/* # pages in range to check */

	unsigned int pages_found;	/* # pages owned found by callbacks */

};



struct notifier_block;

struct mem_section;
@@ -94,27 +81,13 @@ static inline int memory_notify(unsigned long val, void *v) 
{

	return 0;

}

static inline int register_memory_isolate_notifier(struct notifier_block *nb)

{

	return 0;

}

static inline void unregister_memory_isolate_notifier(struct notifier_block *nb)

{

}

static inline int memory_isolate_notify(unsigned long val, void *v)

{

	return 0;

}

#else

extern int register_memory_notifier(struct notifier_block *nb);

extern void unregister_memory_notifier(struct notifier_block *nb);

extern int register_memory_isolate_notifier(struct notifier_block *nb);

extern void unregister_memory_isolate_notifier(struct notifier_block *nb);

int create_memory_block_devices(unsigned long start, unsigned long size);

void remove_memory_block_devices(unsigned long start, unsigned long size);

extern void memory_dev_init(void);

extern int memory_notify(unsigned long val, void *v);

extern int memory_isolate_notify(unsigned long val, void *v);

extern struct memory_block *find_memory_block(struct mem_section *);

typedef int (*walk_memory_blocks_func_t)(struct memory_block *, void *);

extern int walk_memory_blocks(unsigned long start, unsigned long size,

mm/page_isolation.c

+4 −34
Original line number Diff line number Diff line
@@ -18,9 +18,7 @@ 
static int set_migratetype_isolate(struct page *page, int migratetype, int isol_flags)

{

	struct zone *zone;

	unsigned long flags, pfn;

	struct memory_isolate_notify arg;

	int notifier_ret;

	unsigned long flags;

	int ret = -EBUSY;



	zone = page_zone(page);
@@ -35,41 +33,11 @@ static int set_migratetype_isolate(struct page *page, int migratetype, int isol_ 
	if (is_migrate_isolate_page(page))

		goto out;



	pfn = page_to_pfn(page);

	arg.start_pfn = pfn;

	arg.nr_pages = pageblock_nr_pages;

	arg.pages_found = 0;



	/*

	 * It may be possible to isolate a pageblock even if the

	 * migratetype is not MIGRATE_MOVABLE. The memory isolation

	 * notifier chain is used by balloon drivers to return the

	 * number of pages in a range that are held by the balloon

	 * driver to shrink memory. If all the pages are accounted for

	 * by balloons, are free, or on the LRU, isolation can continue.

	 * Later, for example, when memory hotplug notifier runs, these

	 * pages reported as "can be isolated" should be isolated(freed)

	 * by the balloon driver through the memory notifier chain.

	 */

	notifier_ret = memory_isolate_notify(MEM_ISOLATE_COUNT, &arg);

	notifier_ret = notifier_to_errno(notifier_ret);

	if (notifier_ret)

		goto out;

	/*

	 * FIXME: Now, memory hotplug doesn't call shrink_slab() by itself.

	 * We just check MOVABLE pages.

	 */

	if (!has_unmovable_pages(zone, page, arg.pages_found, migratetype,

				 isol_flags))

		ret = 0;



	/*

	 * immobile means "not-on-lru" pages. If immobile is larger than

	 * removable-by-driver pages reported by notifier, we'll fail.

	 */



out:

	if (!ret) {

	if (!has_unmovable_pages(zone, page, 0, migratetype, isol_flags)) {

		unsigned long nr_pages;

		int mt = get_pageblock_migratetype(page);
@@ -79,8 +47,10 @@ static int set_migratetype_isolate(struct page *page, int migratetype, int isol_ 
									NULL);



		__mod_zone_freepage_state(zone, -nr_pages, mt);

		ret = 0;

	}



out:

	spin_unlock_irqrestore(&zone->lock, flags);

	if (!ret)

		drain_all_pages(zone);