[PATCH 1/2 v2] mm: Factor out memory isolate functions

From: Minchan Kim
Date: Wed Jun 27 2012 - 03:51:47 EST


Now mm/page_alloc.c has some memory isolation functions but they
are used oly when we enable CONFIG_{CMA|MEMORY_HOTPLUG|MEMORY_FAILURE}.
So let's make it configurable by new CONFIG_MEMORY_ISOLATION so that it
can reduce binary size and we can check it simple by
CONFIG_MEMORY_ISOLATION,
not if defined CONFIG_{CMA|MEMORY_HOTPLUG|MEMORY_FAILURE}.

This patch is based on next-20120626

* from v1
- rebase on next-20120626

Cc: Andi Kleen <andi@xxxxxxxxxxxxxx>
Cc: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx>
---

Andrew, I know this patch is conflict with current mmotm totally but
I don't know what tree I should use. I hope it's a git tree instead of
quit-based version. Anyway, If you feel it's inconvenient,
let me know it and I will resend it on tree you mention.
Thanks.

drivers/base/Kconfig | 1 +
include/linux/page-isolation.h | 8 ++---
mm/Kconfig | 5 +++
mm/Makefile | 4 +--
mm/page_alloc.c | 71 ----------------------------------------
mm/page_isolation.c | 71 ++++++++++++++++++++++++++++++++++++++++
6 files changed, 83 insertions(+), 77 deletions(-)

diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig
index 9b21469..08b4c52 100644
--- a/drivers/base/Kconfig
+++ b/drivers/base/Kconfig
@@ -196,6 +196,7 @@ config CMA
bool "Contiguous Memory Allocator (EXPERIMENTAL)"
depends on HAVE_DMA_CONTIGUOUS && HAVE_MEMBLOCK && EXPERIMENTAL
select MIGRATION
+ select MEMORY_ISOLATION
help
This enables the Contiguous Memory Allocator which allows drivers
to allocate big physically-contiguous blocks of memory for use with
diff --git a/include/linux/page-isolation.h b/include/linux/page-isolation.h
index 3bdcab3..0569a3e 100644
--- a/include/linux/page-isolation.h
+++ b/include/linux/page-isolation.h
@@ -10,7 +10,7 @@
* free all pages in the range. test_page_isolated() can be used for
* test it.
*/
-extern int
+int
start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn,
unsigned migratetype);

@@ -18,7 +18,7 @@ start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn,
* Changes MIGRATE_ISOLATE to MIGRATE_MOVABLE.
* target range is [start_pfn, end_pfn)
*/
-extern int
+int
undo_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn,
unsigned migratetype);

@@ -30,8 +30,8 @@ int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn);
/*
* Internal functions. Changes pageblock's migrate type.
*/
-extern int set_migratetype_isolate(struct page *page);
-extern void unset_migratetype_isolate(struct page *page, unsigned migratetype);
+int set_migratetype_isolate(struct page *page);
+void unset_migratetype_isolate(struct page *page, unsigned migratetype);


#endif
diff --git a/mm/Kconfig b/mm/Kconfig
index 82fed4e..d5c8019 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -140,9 +140,13 @@ config ARCH_DISCARD_MEMBLOCK
config NO_BOOTMEM
boolean

+config MEMORY_ISOLATION
+ boolean
+
# eventually, we can have this option just 'select SPARSEMEM'
config MEMORY_HOTPLUG
bool "Allow for memory hot-add"
+ select MEMORY_ISOLATION
depends on SPARSEMEM || X86_64_ACPI_NUMA
depends on HOTPLUG && ARCH_ENABLE_MEMORY_HOTPLUG
depends on (IA64 || X86 || PPC_BOOK3S_64 || SUPERH || S390)
@@ -272,6 +276,7 @@ config MEMORY_FAILURE
depends on MMU
depends on ARCH_SUPPORTS_MEMORY_FAILURE
bool "Enable recovery from hardware memory errors"
+ select MEMORY_ISOLATION
help
Enables code to recover from some memory failures on systems
with MCA recovery. This allows a system to continue running
diff --git a/mm/Makefile b/mm/Makefile
index 25e8002..a0c7725 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -15,8 +15,7 @@ obj-y := filemap.o mempool.o oom_kill.o fadvise.o \
maccess.o page_alloc.o page-writeback.o \
readahead.o swap.o truncate.o vmscan.o shmem.o \
prio_tree.o util.o mmzone.o vmstat.o backing-dev.o \
- page_isolation.o mm_init.o mmu_context.o percpu.o \
- compaction.o $(mmu-y)
+ mm_init.o mmu_context.o percpu.o compaction.o $(mmu-y)
obj-y += init-mm.o

ifdef CONFIG_NO_BOOTMEM
@@ -55,3 +54,4 @@ obj-$(CONFIG_HWPOISON_INJECT) += hwpoison-inject.o
obj-$(CONFIG_DEBUG_KMEMLEAK) += kmemleak.o
obj-$(CONFIG_DEBUG_KMEMLEAK_TEST) += kmemleak-test.o
obj-$(CONFIG_CLEANCACHE) += cleancache.o
+obj-$(CONFIG_MEMORY_ISOLATION) += page_isolation.o
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 2c29b1c..c175fa9 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -51,7 +51,6 @@
#include <linux/page_cgroup.h>
#include <linux/debugobjects.h>
#include <linux/kmemleak.h>
-#include <linux/memory.h>
#include <linux/compaction.h>
#include <trace/events/kmem.h>
#include <linux/ftrace_event.h>
@@ -5555,76 +5554,6 @@ bool is_pageblock_removable_nolock(struct page *page)
return __count_immobile_pages(zone, page, 0);
}

-int set_migratetype_isolate(struct page *page)
-{
- struct zone *zone;
- unsigned long flags, pfn;
- struct memory_isolate_notify arg;
- int notifier_ret;
- int ret = -EBUSY;
-
- zone = page_zone(page);
-
- spin_lock_irqsave(&zone->lock, flags);
-
- 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 (__count_immobile_pages(zone, page, arg.pages_found))
- ret = 0;
-
- /*
- * immobile means "not-on-lru" paes. If immobile is larger than
- * removable-by-driver pages reported by notifier, we'll fail.
- */
-
-out:
- if (!ret) {
- set_pageblock_migratetype(page, MIGRATE_ISOLATE);
- move_freepages_block(zone, page, MIGRATE_ISOLATE);
- }
-
- spin_unlock_irqrestore(&zone->lock, flags);
- if (!ret)
- drain_all_pages();
- return ret;
-}
-
-void unset_migratetype_isolate(struct page *page, unsigned migratetype)
-{
- struct zone *zone;
- unsigned long flags;
- zone = page_zone(page);
- spin_lock_irqsave(&zone->lock, flags);
- if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
- goto out;
- set_pageblock_migratetype(page, migratetype);
- move_freepages_block(zone, page, migratetype);
-out:
- spin_unlock_irqrestore(&zone->lock, flags);
-}
-
#ifdef CONFIG_CMA

static unsigned long pfn_max_align_down(unsigned long pfn)
diff --git a/mm/page_isolation.c b/mm/page_isolation.c
index c9f0477..1a9cb36 100644
--- a/mm/page_isolation.c
+++ b/mm/page_isolation.c
@@ -5,8 +5,79 @@
#include <linux/mm.h>
#include <linux/page-isolation.h>
#include <linux/pageblock-flags.h>
+#include <linux/memory.h>
#include "internal.h"

+int set_migratetype_isolate(struct page *page)
+{
+ struct zone *zone;
+ unsigned long flags, pfn;
+ struct memory_isolate_notify arg;
+ int notifier_ret;
+ int ret = -EBUSY;
+
+ zone = page_zone(page);
+
+ spin_lock_irqsave(&zone->lock, flags);
+
+ 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 (__count_immobile_pages(zone, page, arg.pages_found))
+ ret = 0;
+
+ /*
+ * immobile means "not-on-lru" paes. If immobile is larger than
+ * removable-by-driver pages reported by notifier, we'll fail.
+ */
+
+out:
+ if (!ret) {
+ set_pageblock_migratetype(page, MIGRATE_ISOLATE);
+ move_freepages_block(zone, page, MIGRATE_ISOLATE);
+ }
+
+ spin_unlock_irqrestore(&zone->lock, flags);
+ if (!ret)
+ drain_all_pages();
+ return ret;
+}
+
+void unset_migratetype_isolate(struct page *page, unsigned migratetype)
+{
+ struct zone *zone;
+ unsigned long flags;
+ zone = page_zone(page);
+ spin_lock_irqsave(&zone->lock, flags);
+ if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
+ goto out;
+ set_pageblock_migratetype(page, migratetype);
+ move_freepages_block(zone, page, migratetype);
+out:
+ spin_unlock_irqrestore(&zone->lock, flags);
+}
+
static inline struct page *
__first_valid_page(unsigned long pfn, unsigned long nr_pages)
{
--
1.7.9.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/