Messages in this thread | | | Date | Tue, 4 Jun 2013 09:17:26 +0800 | Subject | Re: [v5][PATCH 5/6] mm: vmscan: batch shrink_page_list() locking operations | From | Hillf Danton <> |
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On Tue, Jun 4, 2013 at 4:02 AM, Dave Hansen <dave@sr71.net> wrote: > +/* > + * pages come in here (via remove_list) locked and leave unlocked > + * (on either ret_pages or free_pages) > + * > + * We do this batching so that we free batches of pages with a > + * single mapping->tree_lock acquisition/release. This optimization > + * only makes sense when the pages on remove_list all share a > + * page_mapping(). If this is violated you will BUG_ON(). > + */ > +static int __remove_mapping_batch(struct list_head *remove_list, > + struct list_head *ret_pages, > + struct list_head *free_pages) > +{ > + int nr_reclaimed = 0; > + struct address_space *mapping; > + struct page *page; > + LIST_HEAD(need_free_mapping); > + > + if (list_empty(remove_list)) > + return 0; > + > + mapping = page_mapping(lru_to_page(remove_list)); > + spin_lock_irq(&mapping->tree_lock); > + while (!list_empty(remove_list)) { > + page = lru_to_page(remove_list); > + BUG_ON(!PageLocked(page)); > + BUG_ON(page_mapping(page) != mapping); > + list_del(&page->lru); > + > + if (!__remove_mapping(mapping, page)) { > + unlock_page(page); > + list_add(&page->lru, ret_pages); > + continue; > + } > + list_add(&page->lru, &need_free_mapping); > + } > + spin_unlock_irq(&mapping->tree_lock); > + While reclaiming pages, can we open ears upon IRQ controller, if the page list length is over 10, or even 20?
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