[PATCH v1 11/12] mm: remove the memory isolate notifier

David Hildenbrand
2019-10-31T14:30:50Z

Luckily, we have no users left, so we can get rid of it.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Michal Hocko <mhocko@suse.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>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
drivers/base/memory.c | 19 -------------------
include/linux/memory.h | 27 ---------------------------
mm/page_isolation.c | 27 ++-------------------------
3 files changed, 2 insertions(+), 71 deletions(-)

diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index a757d9ed88a7..03c18c97c2bf 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -73,20 +73,6 @@ 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);
@@ -178,11 +164,6 @@ 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
diff --git a/include/linux/memory.h b/include/linux/memory.h
index 0ebb105eb261..d3fde2d0d94b 100644
--- a/include/linux/memory.h
+++ b/include/linux/memory.h
@@ -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,
diff --git a/mm/page_isolation.c b/mm/page_isolation.c
index 04ee1663cdbe..20d87d18c7cc 100644
--- a/mm/page_isolation.c
+++ b/mm/page_isolation.c
@@ -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);
@@ -35,32 +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))
+ if (!has_unmovable_pages(zone, page, 0, migratetype, isol_flags))
ret = 0;

/*
--
2.21.0