mm: compaction: introduce sync-light migration for use by compaction
This patch adds a lightweight sync migrate operation MIGRATE_SYNC_LIGHT
mode that avoids writing back pages to backing storage. Async compaction
maps to MIGRATE_ASYNC while sync compaction maps to MIGRATE_SYNC_LIGHT.
For other migrate_pages users such as memory hotplug, MIGRATE_SYNC is
used.
This avoids sync compaction stalling for an excessive length of time,
particularly when copying files to a USB stick where there might be a
large number of dirty pages backed by a filesystem that does not support
->writepages.
[aarcange@redhat.com: This patch is heavily based on Andrea's work]
[akpm@linux-foundation.org: fix fs/nfs/write.c build]
[akpm@linux-foundation.org: fix fs/btrfs/disk-io.c build]
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Andy Isaacson <adi@hexapodia.org>
Cc: Nai Xia <nai.xia@gmail.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 1375494..d852566 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -872,7 +872,8 @@
#ifdef CONFIG_MIGRATION
static int btree_migratepage(struct address_space *mapping,
- struct page *newpage, struct page *page, bool sync)
+ struct page *newpage, struct page *page,
+ enum migrate_mode mode)
{
/*
* we can't safely write a btree page from here,
@@ -887,7 +888,7 @@
if (page_has_private(page) &&
!try_to_release_page(page, GFP_KERNEL))
return -EAGAIN;
- return migrate_page(mapping, newpage, page, sync);
+ return migrate_page(mapping, newpage, page, mode);
}
#endif
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 06fd460..1e85a7a 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -584,7 +584,7 @@
static int hugetlbfs_migrate_page(struct address_space *mapping,
struct page *newpage, struct page *page,
- bool sync)
+ enum migrate_mode mode)
{
int rc;
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 114398a..8102db9 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -332,7 +332,7 @@
#ifdef CONFIG_MIGRATION
extern int nfs_migrate_page(struct address_space *,
- struct page *, struct page *, bool);
+ struct page *, struct page *, enum migrate_mode);
#else
#define nfs_migrate_page NULL
#endif
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 889e98b..834f0fe 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -1688,7 +1688,7 @@
#ifdef CONFIG_MIGRATION
int nfs_migrate_page(struct address_space *mapping, struct page *newpage,
- struct page *page, bool sync)
+ struct page *page, enum migrate_mode mode)
{
/*
* If PagePrivate is set, then the page is currently associated with
@@ -1703,7 +1703,7 @@
nfs_fscache_release_page(page, GFP_KERNEL);
- return migrate_page(mapping, newpage, page, sync);
+ return migrate_page(mapping, newpage, page, mode);
}
#endif