From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E6BF4C3F2CF for ; Fri, 28 Feb 2020 03:38:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C7CB924690 for ; Fri, 28 Feb 2020 03:38:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730846AbgB1Dio (ORCPT ); Thu, 27 Feb 2020 22:38:44 -0500 Received: from mga09.intel.com ([134.134.136.24]:36522 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730835AbgB1Dio (ORCPT ); Thu, 27 Feb 2020 22:38:44 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 27 Feb 2020 19:38:43 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,493,1574150400"; d="scan'208";a="232107370" Received: from yhuang-dev.sh.intel.com ([10.239.159.23]) by orsmga008.jf.intel.com with ESMTP; 27 Feb 2020 19:38:40 -0800 From: "Huang, Ying" To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Huang Ying , Dave Hansen , David Hildenbrand , Mel Gorman , Vlastimil Babka , Zi Yan , Michal Hocko , Peter Zijlstra , Minchan Kim , Johannes Weiner , Hugh Dickins Subject: [RFC 2/3] mm: Add a new page flag PageLayzyFree() for MADV_FREE Date: Fri, 28 Feb 2020 11:38:18 +0800 Message-Id: <20200228033819.3857058-3-ying.huang@intel.com> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200228033819.3857058-1-ying.huang@intel.com> References: <20200228033819.3857058-1-ying.huang@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Huang Ying Now !PageSwapBacked() is used as the flag for the pages freed lazily via MADV_FREE. This isn't obvious enough. So Dave suggested to add a new page flag for that to improve the code readability. Signed-off-by: "Huang, Ying" Suggested-by: Dave Hansen Cc: David Hildenbrand Cc: Mel Gorman Cc: Vlastimil Babka Cc: Zi Yan Cc: Michal Hocko Cc: Peter Zijlstra Cc: Minchan Kim Cc: Johannes Weiner Cc: Hugh Dickins --- include/linux/page-flags.h | 25 +++++++++++++++++++++++++ mm/rmap.c | 6 +++--- mm/swap.c | 11 +++-------- mm/vmscan.c | 7 +++---- 4 files changed, 34 insertions(+), 15 deletions(-) diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 49c2697046b9..759748fbcfad 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -498,6 +498,31 @@ static __always_inline int PageKsm(struct page *page) TESTPAGEFLAG_FALSE(Ksm) #endif +/* + * For pages freed lazily via MADV_FREE. lazyfree pages are clean + * anonymous pages. They have SwapBacked flag cleared to distinguish + * with normal anonymous pages + */ +static __always_inline int PageLazyFree(struct page *page) +{ + page = compound_head(page); + return PageAnon(page) && !PageSwapBacked(page); +} + +static __always_inline void SetPageLazyFree(struct page *page) +{ + VM_BUG_ON_PAGE(PageTail(page), page); + VM_BUG_ON_PAGE(!PageAnon(page), page); + ClearPageSwapBacked(page); +} + +static __always_inline void ClearPageLazyFree(struct page *page) +{ + VM_BUG_ON_PAGE(PageTail(page), page); + VM_BUG_ON_PAGE(!PageAnon(page), page); + SetPageSwapBacked(page); +} + u64 stable_page_flags(struct page *page); static inline int PageUptodate(struct page *page) diff --git a/mm/rmap.c b/mm/rmap.c index 03c5b116d30e..1dcbb1771dd7 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1598,7 +1598,7 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma, * Store the swap location in the pte. * See handle_pte_fault() ... */ - if (unlikely(PageSwapBacked(page) != PageSwapCache(page))) { + if (unlikely(PageLazyFree(page) == PageSwapCache(page))) { WARN_ON_ONCE(1); ret = false; /* We have to invalidate as we cleared the pte */ @@ -1609,7 +1609,7 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma, } /* MADV_FREE page check */ - if (!PageSwapBacked(page)) { + if (PageLazyFree(page)) { if (!PageDirty(page)) { /* Invalidate as we cleared the pte */ mmu_notifier_invalidate_range(mm, @@ -1623,7 +1623,7 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma, * discarded. Remap the page to page table. */ set_pte_at(mm, address, pvmw.pte, pteval); - SetPageSwapBacked(page); + ClearPageLazyFree(page); ret = false; page_vma_mapped_walk_done(&pvmw); break; diff --git a/mm/swap.c b/mm/swap.c index f502a2155e85..bd5e40e14c94 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -564,7 +564,7 @@ static void lru_deactivate_fn(struct page *page, struct lruvec *lruvec, static void lru_lazyfree_fn(struct page *page, struct lruvec *lruvec, void *arg) { - if (PageLRU(page) && PageAnon(page) && PageSwapBacked(page) && + if (PageLRU(page) && PageAnon(page) && !PageLazyFree(page) && !PageSwapCache(page) && !PageUnevictable(page)) { bool active = PageActive(page); @@ -572,12 +572,7 @@ static void lru_lazyfree_fn(struct page *page, struct lruvec *lruvec, LRU_INACTIVE_ANON + active); ClearPageActive(page); ClearPageReferenced(page); - /* - * lazyfree pages are clean anonymous pages. They have - * SwapBacked flag cleared to distinguish normal anonymous - * pages - */ - ClearPageSwapBacked(page); + SetPageLazyFree(page); add_page_to_lru_list(page, lruvec, LRU_INACTIVE_FILE); __count_vm_events(PGLAZYFREE, hpage_nr_pages(page)); @@ -678,7 +673,7 @@ void deactivate_page(struct page *page) */ void mark_page_lazyfree(struct page *page) { - if (PageLRU(page) && PageAnon(page) && PageSwapBacked(page) && + if (PageLRU(page) && PageAnon(page) && !PageLazyFree(page) && !PageSwapCache(page) && !PageUnevictable(page)) { struct pagevec *pvec = &get_cpu_var(lru_lazyfree_pvecs); diff --git a/mm/vmscan.c b/mm/vmscan.c index f14c8c6069a6..0aaee7052fb0 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1043,8 +1043,7 @@ static void page_check_dirty_writeback(struct page *page, * Anonymous pages are not handled by flushers and must be written * from reclaim context. Do not stall reclaim based on them */ - if (!page_is_file_cache(page) || - (PageAnon(page) && !PageSwapBacked(page))) { + if (!page_is_file_cache(page) || PageLazyFree(page)) { *dirty = false; *writeback = false; return; @@ -1235,7 +1234,7 @@ static unsigned long shrink_page_list(struct list_head *page_list, * Try to allocate it some swap space here. * Lazyfree page could be freed directly */ - if (PageAnon(page) && PageSwapBacked(page)) { + if (PageAnon(page) && !PageLazyFree(page)) { if (!PageSwapCache(page)) { if (!(sc->gfp_mask & __GFP_IO)) goto keep_locked; @@ -1411,7 +1410,7 @@ static unsigned long shrink_page_list(struct list_head *page_list, } } - if (PageAnon(page) && !PageSwapBacked(page)) { + if (PageLazyFree(page)) { /* follow __remove_mapping for reference */ if (!page_ref_freeze(page, 1)) goto keep_locked; -- 2.25.0