Make page_referenced() container aware. Without this patch, page_referenced() can cause a page to be skipped while reclaiming pages. This patch ensures that other containers do not hold pages in a particular container hostage. It is required to ensure that shared pages are freed from a container when they are not actively referenced from the container that brought them in Signed-off-by: Balbir Singh --- include/linux/rmap.h | 5 +++-- mm/rmap.c | 26 ++++++++++++++++++++------ mm/vmscan.c | 4 ++-- 3 files changed, 25 insertions(+), 10 deletions(-) diff -puN mm/vmscan.c~rss-implement-per-container-page-referenced mm/vmscan.c --- linux-2.6.20/mm/vmscan.c~rss-implement-per-container-page-referenced 2007-04-26 23:28:44.000000000 +0530 +++ linux-2.6.20-balbir/mm/vmscan.c 2007-04-27 00:04:38.000000000 +0530 @@ -489,7 +489,7 @@ static unsigned long shrink_page_list(st if (PageWriteback(page)) goto keep_locked; - referenced = page_referenced(page, 1); + referenced = page_referenced(page, 1, sc->cnt); /* In active use or really unfreeable? Activate it. */ if (referenced && page_mapping_inuse(page)) goto activate_locked; @@ -852,7 +852,7 @@ force_reclaim_mapped: if (page_mapped(page)) { if (!reclaim_mapped || (total_swap_pages == 0 && PageAnon(page)) || - page_referenced(page, 0)) { + page_referenced(page, 0, sc->cnt)) { list_add(&page->lru, &l_active); continue; } diff -puN mm/rmap.c~rss-implement-per-container-page-referenced mm/rmap.c --- linux-2.6.20/mm/rmap.c~rss-implement-per-container-page-referenced 2007-04-26 23:28:44.000000000 +0530 +++ linux-2.6.20-balbir/mm/rmap.c 2007-04-26 23:33:41.000000000 +0530 @@ -318,7 +318,7 @@ out: return referenced; } -static int page_referenced_anon(struct page *page) +static int page_referenced_anon(struct page *page, struct rss_container *cnt) { unsigned int mapcount; struct anon_vma *anon_vma; @@ -331,6 +331,13 @@ static int page_referenced_anon(struct p mapcount = page_mapcount(page); list_for_each_entry(vma, &anon_vma->head, anon_vma_node) { + /* + * If we are reclaiming on behalf of a container, skip + * counting on behalf of references from different + * containers + */ + if (cnt && (vma->vm_mm->rss_container != cnt)) + continue; referenced += page_referenced_one(page, vma, &mapcount); if (!mapcount) break; @@ -350,7 +357,7 @@ static int page_referenced_anon(struct p * * This function is only called from page_referenced for object-based pages. */ -static int page_referenced_file(struct page *page) +static int page_referenced_file(struct page *page, struct rss_container *cnt) { unsigned int mapcount; struct address_space *mapping = page->mapping; @@ -383,6 +390,13 @@ static int page_referenced_file(struct p mapcount = page_mapcount(page); vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) { + /* + * If we are reclaiming on behalf of a container, skip + * counting on behalf of references from different + * containers + */ + if (cnt && (vma->vm_mm->rss_container != cnt)) + continue; if ((vma->vm_flags & (VM_LOCKED|VM_MAYSHARE)) == (VM_LOCKED|VM_MAYSHARE)) { referenced++; @@ -405,7 +419,7 @@ static int page_referenced_file(struct p * Quick test_and_clear_referenced for all mappings to a page, * returns the number of ptes which referenced the page. */ -int page_referenced(struct page *page, int is_locked) +int page_referenced(struct page *page, int is_locked, struct rss_container *cnt) { int referenced = 0; @@ -417,14 +431,14 @@ int page_referenced(struct page *page, i if (page_mapped(page) && page->mapping) { if (PageAnon(page)) - referenced += page_referenced_anon(page); + referenced += page_referenced_anon(page, cnt); else if (is_locked) - referenced += page_referenced_file(page); + referenced += page_referenced_file(page, cnt); else if (TestSetPageLocked(page)) referenced++; else { if (page->mapping) - referenced += page_referenced_file(page); + referenced += page_referenced_file(page, cnt); unlock_page(page); } } diff -puN include/linux/rmap.h~rss-implement-per-container-page-referenced include/linux/rmap.h --- linux-2.6.20/include/linux/rmap.h~rss-implement-per-container-page-referenced 2007-04-26 23:28:44.000000000 +0530 +++ linux-2.6.20-balbir/include/linux/rmap.h 2007-04-26 23:29:31.000000000 +0530 @@ -8,6 +8,7 @@ #include #include #include +#include /* * The anon_vma heads a list of private "related" vmas, to scan if @@ -93,7 +94,7 @@ static inline void page_dup_rmap(struct /* * Called from mm/vmscan.c to handle paging out */ -int page_referenced(struct page *, int is_locked); +int page_referenced(struct page *, int is_locked, struct rss_container *cnt); int try_to_unmap(struct page *, int ignore_refs); /* @@ -121,7 +122,7 @@ int page_mkclean(struct page *); #define anon_vma_prepare(vma) (0) #define anon_vma_link(vma) do {} while (0) -#define page_referenced(page,l) TestClearPageReferenced(page) +#define page_referenced(page,l,cnt) TestClearPageReferenced(page) #define try_to_unmap(page, refs) SWAP_FAIL static inline int page_mkclean(struct page *page) _