Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753304AbbK3Gj6 (ORCPT ); Mon, 30 Nov 2015 01:39:58 -0500 Received: from LGEAMRELO11.lge.com ([156.147.23.51]:33675 "EHLO lgeamrelo11.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753098AbbK3Gj3 (ORCPT ); Mon, 30 Nov 2015 01:39:29 -0500 X-Original-SENDERIP: 156.147.1.125 X-Original-MAILFROM: minchan@kernel.org X-Original-SENDERIP: 10.177.223.161 X-Original-MAILFROM: minchan@kernel.org From: Minchan Kim To: Andrew Morton Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Michael Kerrisk , linux-api@vger.kernel.org, Hugh Dickins , Johannes Weiner , Rik van Riel , Mel Gorman , KOSAKI Motohiro , Jason Evans , Daniel Micay , "Kirill A. Shutemov" , Shaohua Li , Michal Hocko , yalin.wang2010@gmail.com, Andy Lutomirski , Minchan Kim Subject: [PATCH v5 05/12] mm: move lazily freed pages to inactive list Date: Mon, 30 Nov 2015 15:39:36 +0900 Message-Id: <1448865583-2446-6-git-send-email-minchan@kernel.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1448865583-2446-1-git-send-email-minchan@kernel.org> References: <1448865583-2446-1-git-send-email-minchan@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5352 Lines: 150 MADV_FREE is a hint that it's okay to discard pages if there is memory pressure and we use reclaimers(ie, kswapd and direct reclaim) to free them so there is no value keeping them in the active anonymous LRU so this patch moves them to inactive LRU list's head. This means that MADV_FREE-ed pages which were living on the inactive list are reclaimed first because they are more likely to be cold rather than recently active pages. An arguable issue for the approach would be whether we should put the page to the head or tail of the inactive list. I chose head because the kernel cannot make sure it's really cold or warm for every MADV_FREE usecase but at least we know it's not *hot*, so landing of inactive head would be a comprimise for various usecases. This fixes suboptimal behavior of MADV_FREE when pages living on the active list will sit there for a long time even under memory pressure while the inactive list is reclaimed heavily. This basically breaks the whole purpose of using MADV_FREE to help the system to free memory which is might not be used. Cc: Johannes Weiner Cc: Mel Gorman Cc: Rik van Riel Cc: Shaohua Li Acked-by: Hugh Dickins Acked-by: Michal Hocko Signed-off-by: Minchan Kim --- include/linux/swap.h | 1 + mm/madvise.c | 2 ++ mm/swap.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 47 insertions(+) diff --git a/include/linux/swap.h b/include/linux/swap.h index 457181844b6e..d08feef3d047 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -308,6 +308,7 @@ extern void lru_add_drain_cpu(int cpu); extern void lru_add_drain_all(void); extern void rotate_reclaimable_page(struct page *page); extern void deactivate_file_page(struct page *page); +extern void deactivate_page(struct page *page); extern void swap_setup(void); extern void add_page_to_unevictable_list(struct page *page); diff --git a/mm/madvise.c b/mm/madvise.c index 8de3d9a636c9..975e24e4c134 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -366,6 +366,8 @@ static int madvise_free_pte_range(pmd_t *pmd, unsigned long addr, ptent = pte_mkold(ptent); ptent = pte_mkclean(ptent); set_pte_at(mm, addr, pte, ptent); + if (PageActive(page)) + deactivate_page(page); tlb_remove_tlb_entry(tlb, pte, addr); } } diff --git a/mm/swap.c b/mm/swap.c index abffc33bb975..674e2c93da4e 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -45,6 +45,7 @@ int page_cluster; static DEFINE_PER_CPU(struct pagevec, lru_add_pvec); static DEFINE_PER_CPU(struct pagevec, lru_rotate_pvecs); static DEFINE_PER_CPU(struct pagevec, lru_deactivate_file_pvecs); +static DEFINE_PER_CPU(struct pagevec, lru_deactivate_pvecs); /* * This path almost never happens for VM activity - pages are normally @@ -554,6 +555,24 @@ static void lru_deactivate_file_fn(struct page *page, struct lruvec *lruvec, update_page_reclaim_stat(lruvec, file, 0); } + +static void lru_deactivate_fn(struct page *page, struct lruvec *lruvec, + void *arg) +{ + if (PageLRU(page) && PageActive(page) && !PageUnevictable(page)) { + int file = page_is_file_cache(page); + int lru = page_lru_base_type(page); + + del_page_from_lru_list(page, lruvec, lru + LRU_ACTIVE); + ClearPageActive(page); + ClearPageReferenced(page); + add_page_to_lru_list(page, lruvec, lru); + + __count_vm_event(PGDEACTIVATE); + update_page_reclaim_stat(lruvec, file, 0); + } +} + /* * Drain pages out of the cpu's pagevecs. * Either "cpu" is the current CPU, and preemption has already been @@ -580,6 +599,10 @@ void lru_add_drain_cpu(int cpu) if (pagevec_count(pvec)) pagevec_lru_move_fn(pvec, lru_deactivate_file_fn, NULL); + pvec = &per_cpu(lru_deactivate_pvecs, cpu); + if (pagevec_count(pvec)) + pagevec_lru_move_fn(pvec, lru_deactivate_fn, NULL); + activate_page_drain(cpu); } @@ -609,6 +632,26 @@ void deactivate_file_page(struct page *page) } } +/** + * deactivate_page - deactivate a page + * @page: page to deactivate + * + * deactivate_page() moves @page to the inactive list if @page was on the active + * list and was not an unevictable page. This is done to accelerate the reclaim + * of @page. + */ +void deactivate_page(struct page *page) +{ + if (PageLRU(page) && PageActive(page) && !PageUnevictable(page)) { + struct pagevec *pvec = &get_cpu_var(lru_deactivate_pvecs); + + page_cache_get(page); + if (!pagevec_add(pvec, page)) + pagevec_lru_move_fn(pvec, lru_deactivate_fn, NULL); + put_cpu_var(lru_deactivate_pvecs); + } +} + void lru_add_drain(void) { lru_add_drain_cpu(get_cpu()); @@ -638,6 +681,7 @@ void lru_add_drain_all(void) if (pagevec_count(&per_cpu(lru_add_pvec, cpu)) || pagevec_count(&per_cpu(lru_rotate_pvecs, cpu)) || pagevec_count(&per_cpu(lru_deactivate_file_pvecs, cpu)) || + pagevec_count(&per_cpu(lru_deactivate_pvecs, cpu)) || need_activate_page_drain(cpu)) { INIT_WORK(work, lru_add_drain_per_cpu); schedule_work_on(cpu, work); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/