From 6fe6b7e35785e3232ffe7f81d3893f1316710a02 Mon Sep 17 00:00:00 2001 From: Wu Fengguang Date: Tue, 16 Jun 2009 15:33:05 -0700 Subject: [PATCH] vmscan: report vm_flags in page_referenced() Collect vma->vm_flags of the VMAs that actually referenced the page. This is preparing for more informed reclaim heuristics, eg. to protect executable file pages more aggressively. For now only the VM_EXEC bit will be used by the caller. Thanks to Johannes, Peter and Minchan for all the good tips. Acked-by: Peter Zijlstra Reviewed-by: Rik van Riel Reviewed-by: Minchan Kim Reviewed-by: Johannes Weiner Signed-off-by: Wu Fengguang Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/rmap.h | 5 +++-- mm/rmap.c | 37 ++++++++++++++++++++++++++----------- mm/vmscan.c | 7 +++++-- 3 files changed, 34 insertions(+), 15 deletions(-) diff --git a/include/linux/rmap.h b/include/linux/rmap.h index 619379a1dd98..216d024f830d 100644 --- a/include/linux/rmap.h +++ b/include/linux/rmap.h @@ -83,7 +83,8 @@ static inline void page_dup_rmap(struct page *page, struct vm_area_struct *vma, /* * Called from mm/vmscan.c to handle paging out */ -int page_referenced(struct page *, int is_locked, struct mem_cgroup *cnt); +int page_referenced(struct page *, int is_locked, + struct mem_cgroup *cnt, unsigned long *vm_flags); int try_to_unmap(struct page *, int ignore_refs); /* @@ -117,7 +118,7 @@ int try_to_munlock(struct page *); #define anon_vma_prepare(vma) (0) #define anon_vma_link(vma) do {} while (0) -#define page_referenced(page,l,cnt) TestClearPageReferenced(page) +#define page_referenced(page, locked, cnt, flags) TestClearPageReferenced(page) #define try_to_unmap(page, refs) SWAP_FAIL static inline int page_mkclean(struct page *page) diff --git a/mm/rmap.c b/mm/rmap.c index 316c9d6930ad..c9ccc1a72dc3 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -333,7 +333,9 @@ static int page_mapped_in_vma(struct page *page, struct vm_area_struct *vma) * repeatedly from either page_referenced_anon or page_referenced_file. */ static int page_referenced_one(struct page *page, - struct vm_area_struct *vma, unsigned int *mapcount) + struct vm_area_struct *vma, + unsigned int *mapcount, + unsigned long *vm_flags) { struct mm_struct *mm = vma->vm_mm; unsigned long address; @@ -381,11 +383,14 @@ out_unmap: (*mapcount)--; pte_unmap_unlock(pte, ptl); out: + if (referenced) + *vm_flags |= vma->vm_flags; return referenced; } static int page_referenced_anon(struct page *page, - struct mem_cgroup *mem_cont) + struct mem_cgroup *mem_cont, + unsigned long *vm_flags) { unsigned int mapcount; struct anon_vma *anon_vma; @@ -405,7 +410,8 @@ static int page_referenced_anon(struct page *page, */ if (mem_cont && !mm_match_cgroup(vma->vm_mm, mem_cont)) continue; - referenced += page_referenced_one(page, vma, &mapcount); + referenced += page_referenced_one(page, vma, + &mapcount, vm_flags); if (!mapcount) break; } @@ -418,6 +424,7 @@ static int page_referenced_anon(struct page *page, * page_referenced_file - referenced check for object-based rmap * @page: the page we're checking references on. * @mem_cont: target memory controller + * @vm_flags: collect encountered vma->vm_flags who actually referenced the page * * For an object-based mapped page, find all the places it is mapped and * check/clear the referenced flag. This is done by following the page->mapping @@ -427,7 +434,8 @@ static int page_referenced_anon(struct page *page, * This function is only called from page_referenced for object-based pages. */ static int page_referenced_file(struct page *page, - struct mem_cgroup *mem_cont) + struct mem_cgroup *mem_cont, + unsigned long *vm_flags) { unsigned int mapcount; struct address_space *mapping = page->mapping; @@ -467,7 +475,8 @@ static int page_referenced_file(struct page *page, */ if (mem_cont && !mm_match_cgroup(vma->vm_mm, mem_cont)) continue; - referenced += page_referenced_one(page, vma, &mapcount); + referenced += page_referenced_one(page, vma, + &mapcount, vm_flags); if (!mapcount) break; } @@ -481,29 +490,35 @@ static int page_referenced_file(struct page *page, * @page: the page to test * @is_locked: caller holds lock on the page * @mem_cont: target memory controller + * @vm_flags: collect encountered vma->vm_flags who actually referenced the page * * 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, - struct mem_cgroup *mem_cont) +int page_referenced(struct page *page, + int is_locked, + struct mem_cgroup *mem_cont, + unsigned long *vm_flags) { int referenced = 0; if (TestClearPageReferenced(page)) referenced++; + *vm_flags = 0; if (page_mapped(page) && page->mapping) { if (PageAnon(page)) - referenced += page_referenced_anon(page, mem_cont); + referenced += page_referenced_anon(page, mem_cont, + vm_flags); else if (is_locked) - referenced += page_referenced_file(page, mem_cont); + referenced += page_referenced_file(page, mem_cont, + vm_flags); else if (!trylock_page(page)) referenced++; else { if (page->mapping) - referenced += - page_referenced_file(page, mem_cont); + referenced += page_referenced_file(page, + mem_cont, vm_flags); unlock_page(page); } } diff --git a/mm/vmscan.c b/mm/vmscan.c index 52339dd7bf85..6be2068f61c8 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -577,6 +577,7 @@ static unsigned long shrink_page_list(struct list_head *page_list, struct pagevec freed_pvec; int pgactivate = 0; unsigned long nr_reclaimed = 0; + unsigned long vm_flags; cond_resched(); @@ -627,7 +628,8 @@ static unsigned long shrink_page_list(struct list_head *page_list, goto keep_locked; } - referenced = page_referenced(page, 1, sc->mem_cgroup); + referenced = page_referenced(page, 1, + sc->mem_cgroup, &vm_flags); /* In active use or really unfreeable? Activate it. */ if (sc->order <= PAGE_ALLOC_COSTLY_ORDER && referenced && page_mapping_inuse(page)) @@ -1208,6 +1210,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone, { unsigned long pgmoved; unsigned long pgscanned; + unsigned long vm_flags; LIST_HEAD(l_hold); /* The pages which were snipped off */ LIST_HEAD(l_inactive); struct page *page; @@ -1248,7 +1251,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone, /* page_referenced clears PageReferenced */ if (page_mapping_inuse(page) && - page_referenced(page, 0, sc->mem_cgroup)) + page_referenced(page, 0, sc->mem_cgroup, &vm_flags)) pgmoved++; list_add(&page->lru, &l_inactive);