diff options
| -rw-r--r-- | mm/vmscan.c | 56 |
1 files changed, 43 insertions, 13 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c index 5cbf64dd79c..ba4e87df3fc 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -579,6 +579,40 @@ redo: put_page(page); /* drop ref from isolate */ } +enum page_references { + PAGEREF_RECLAIM, + PAGEREF_RECLAIM_CLEAN, + PAGEREF_ACTIVATE, +}; + +static enum page_references page_check_references(struct page *page, + struct scan_control *sc) +{ + unsigned long vm_flags; + int referenced; + + referenced = page_referenced(page, 1, sc->mem_cgroup, &vm_flags); + if (!referenced) + return PAGEREF_RECLAIM; + + /* Lumpy reclaim - ignore references */ + if (sc->order > PAGE_ALLOC_COSTLY_ORDER) + return PAGEREF_RECLAIM; + + /* + * Mlock lost the isolation race with us. Let try_to_unmap() + * move the page to the unevictable list. + */ + if (vm_flags & VM_LOCKED) + return PAGEREF_RECLAIM; + + if (page_mapping_inuse(page)) + return PAGEREF_ACTIVATE; + + /* Reclaim if clean, defer dirty pages to writeback */ + return PAGEREF_RECLAIM_CLEAN; +} + /* * shrink_page_list() returns the number of reclaimed pages */ @@ -590,16 +624,15 @@ 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(); pagevec_init(&freed_pvec, 1); while (!list_empty(page_list)) { + enum page_references references; struct address_space *mapping; struct page *page; int may_enter_fs; - int referenced; cond_resched(); @@ -641,17 +674,14 @@ static unsigned long shrink_page_list(struct list_head *page_list, goto keep_locked; } - referenced = page_referenced(page, 1, - sc->mem_cgroup, &vm_flags); - /* - * In active use or really unfreeable? Activate it. - * If page which have PG_mlocked lost isoltation race, - * try_to_unmap moves it to unevictable list - */ - if (sc->order <= PAGE_ALLOC_COSTLY_ORDER && - referenced && page_mapping_inuse(page) - && !(vm_flags & VM_LOCKED)) + references = page_check_references(page, sc); + switch (references) { + case PAGEREF_ACTIVATE: goto activate_locked; + case PAGEREF_RECLAIM: + case PAGEREF_RECLAIM_CLEAN: + ; /* try to reclaim the page below */ + } /* * Anonymous process memory has backing store? @@ -685,7 +715,7 @@ static unsigned long shrink_page_list(struct list_head *page_list, } if (PageDirty(page)) { - if (sc->order <= PAGE_ALLOC_COSTLY_ORDER && referenced) + if (references == PAGEREF_RECLAIM_CLEAN) goto keep_locked; if (!may_enter_fs) goto keep_locked; |