From b20a35035f983f4ac7e29c4a68f30e43510007e0 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Wed, 22 Mar 2006 00:09:12 -0800 Subject: [PATCH] page migration reorg Centralize the page migration functions in anticipation of additional tinkering. Creates a new file mm/migrate.c 1. Extract buffer_migrate_page() from fs/buffer.c 2. Extract central migration code from vmscan.c 3. Extract some components from mempolicy.c 4. Export pageout() and remove_from_swap() from vmscan.c 5. Make it possible to configure NUMA systems without page migration and non-NUMA systems with page migration. I had to so some #ifdeffing in mempolicy.c that may need a cleanup. Signed-off-by: Christoph Lameter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/mempolicy.c | 113 ++++++++++++--------------------------------------------- 1 file changed, 23 insertions(+), 90 deletions(-) (limited to 'mm/mempolicy.c') diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 96195dcb62e..e93cc740c22 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -86,6 +86,7 @@ #include #include #include +#include #include #include @@ -95,9 +96,6 @@ #define MPOL_MF_INVERT (MPOL_MF_INTERNAL << 1) /* Invert check for nodemask */ #define MPOL_MF_STATS (MPOL_MF_INTERNAL << 2) /* Gather statistics */ -/* The number of pages to migrate per call to migrate_pages() */ -#define MIGRATE_CHUNK_SIZE 256 - static struct kmem_cache *policy_cache; static struct kmem_cache *sn_cache; @@ -331,17 +329,10 @@ check_range(struct mm_struct *mm, unsigned long start, unsigned long end, struct vm_area_struct *first, *vma, *prev; if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) { - /* Must have swap device for migration */ - if (nr_swap_pages <= 0) - return ERR_PTR(-ENODEV); - /* - * Clear the LRU lists so pages can be isolated. - * Note that pages may be moved off the LRU after we have - * drained them. Those pages will fail to migrate like other - * pages that may be busy. - */ - lru_add_drain_all(); + err = migrate_prep(); + if (err) + return ERR_PTR(err); } first = find_vma(mm, start); @@ -550,92 +541,18 @@ long do_get_mempolicy(int *policy, nodemask_t *nmask, return err; } +#ifdef CONFIG_MIGRATION /* * page migration */ - static void migrate_page_add(struct page *page, struct list_head *pagelist, unsigned long flags) { /* * Avoid migrating a page that is shared with others. */ - if ((flags & MPOL_MF_MOVE_ALL) || page_mapcount(page) == 1) { - if (isolate_lru_page(page)) - list_add_tail(&page->lru, pagelist); - } -} - -/* - * Migrate the list 'pagelist' of pages to a certain destination. - * - * Specify destination with either non-NULL vma or dest_node >= 0 - * Return the number of pages not migrated or error code - */ -static int migrate_pages_to(struct list_head *pagelist, - struct vm_area_struct *vma, int dest) -{ - LIST_HEAD(newlist); - LIST_HEAD(moved); - LIST_HEAD(failed); - int err = 0; - unsigned long offset = 0; - int nr_pages; - struct page *page; - struct list_head *p; - -redo: - nr_pages = 0; - list_for_each(p, pagelist) { - if (vma) { - /* - * The address passed to alloc_page_vma is used to - * generate the proper interleave behavior. We fake - * the address here by an increasing offset in order - * to get the proper distribution of pages. - * - * No decision has been made as to which page - * a certain old page is moved to so we cannot - * specify the correct address. - */ - page = alloc_page_vma(GFP_HIGHUSER, vma, - offset + vma->vm_start); - offset += PAGE_SIZE; - } - else - page = alloc_pages_node(dest, GFP_HIGHUSER, 0); - - if (!page) { - err = -ENOMEM; - goto out; - } - list_add_tail(&page->lru, &newlist); - nr_pages++; - if (nr_pages > MIGRATE_CHUNK_SIZE) - break; - } - err = migrate_pages(pagelist, &newlist, &moved, &failed); - - putback_lru_pages(&moved); /* Call release pages instead ?? */ - - if (err >= 0 && list_empty(&newlist) && !list_empty(pagelist)) - goto redo; -out: - /* Return leftover allocated pages */ - while (!list_empty(&newlist)) { - page = list_entry(newlist.next, struct page, lru); - list_del(&page->lru); - __free_page(page); - } - list_splice(&failed, pagelist); - if (err < 0) - return err; - - /* Calculate number of leftover pages */ - nr_pages = 0; - list_for_each(p, pagelist) - nr_pages++; - return nr_pages; + if ((flags & MPOL_MF_MOVE_ALL) || page_mapcount(page) == 1) + isolate_lru_page(page, pagelist); } /* @@ -742,8 +659,23 @@ int do_migrate_pages(struct mm_struct *mm, if (err < 0) return err; return busy; + } +#else + +static void migrate_page_add(struct page *page, struct list_head *pagelist, + unsigned long flags) +{ +} + +int do_migrate_pages(struct mm_struct *mm, + const nodemask_t *from_nodes, const nodemask_t *to_nodes, int flags) +{ + return -ENOSYS; +} +#endif + long do_mbind(unsigned long start, unsigned long len, unsigned long mode, nodemask_t *nmask, unsigned long flags) { @@ -808,6 +740,7 @@ long do_mbind(unsigned long start, unsigned long len, if (!err && nr_failed && (flags & MPOL_MF_STRICT)) err = -EIO; } + if (!list_empty(&pagelist)) putback_lru_pages(&pagelist); -- cgit v1.2.3