From e965f9630c651fa4249039fd4b80c9392d07a856 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Wed, 1 Feb 2006 03:05:41 -0800 Subject: [PATCH] Direct Migration V9: Avoid writeback / page_migrate() method Migrate a page with buffers without requiring writeback This introduces a new address space operation migratepage() that may be used by a filesystem to implement its own version of page migration. A version is provided that migrates buffers attached to pages. Some filesystems (ext2, ext3, xfs) are modified to utilize this feature. The swapper address space operation are modified so that a regular migrate_page() will occur for anonymous pages without writeback (migrate_pages forces every anonymous page to have a swap entry). Signed-off-by: Mike Kravetz Signed-off-by: Christoph Lameter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/vmscan.c | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) (limited to 'mm/vmscan.c') diff --git a/mm/vmscan.c b/mm/vmscan.c index 5e98b86feb74..5a610804cd06 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -614,6 +614,15 @@ int putback_lru_pages(struct list_head *l) return count; } +/* + * Non migratable page + */ +int fail_migrate_page(struct page *newpage, struct page *page) +{ + return -EIO; +} +EXPORT_SYMBOL(fail_migrate_page); + /* * swapout a single page * page is locked upon entry, unlocked on exit @@ -659,6 +668,7 @@ unlock_retry: retry: return -EAGAIN; } +EXPORT_SYMBOL(swap_page); /* * Page migration was first developed in the context of the memory hotplug @@ -674,7 +684,7 @@ retry: * Remove references for a page and establish the new page with the correct * basic settings to be able to stop accesses to the page. */ -static int migrate_page_remove_references(struct page *newpage, +int migrate_page_remove_references(struct page *newpage, struct page *page, int nr_refs) { struct address_space *mapping = page_mapping(page); @@ -749,6 +759,7 @@ static int migrate_page_remove_references(struct page *newpage, return 0; } +EXPORT_SYMBOL(migrate_page_remove_references); /* * Copy the page to its new location @@ -788,6 +799,7 @@ void migrate_page_copy(struct page *newpage, struct page *page) if (PageWriteback(newpage)) end_page_writeback(newpage); } +EXPORT_SYMBOL(migrate_page_copy); /* * Common logic to directly migrate a single page suitable for @@ -815,6 +827,7 @@ int migrate_page(struct page *newpage, struct page *page) remove_from_swap(newpage); return 0; } +EXPORT_SYMBOL(migrate_page); /* * migrate_pages @@ -914,6 +927,11 @@ redo: if (!mapping) goto unlock_both; + if (mapping->a_ops->migratepage) { + rc = mapping->a_ops->migratepage(newpage, page); + goto unlock_both; + } + /* * Trigger writeout if page is dirty */ -- cgit v1.2.3