From patchwork Tue Mar 3 03:37:38 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Huang, Ying" X-Patchwork-Id: 11417113 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 424E8138D for ; Tue, 3 Mar 2020 03:37:58 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 187DA2173E for ; Tue, 3 Mar 2020 03:37:58 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 187DA2173E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 449116B0006; Mon, 2 Mar 2020 22:37:57 -0500 (EST) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 3F92A6B0007; Mon, 2 Mar 2020 22:37:57 -0500 (EST) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 337486B0008; Mon, 2 Mar 2020 22:37:57 -0500 (EST) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0246.hostedemail.com [216.40.44.246]) by kanga.kvack.org (Postfix) with ESMTP id 1CB5E6B0006 for ; Mon, 2 Mar 2020 22:37:57 -0500 (EST) Received: from smtpin16.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 006901AA8E for ; Tue, 3 Mar 2020 03:37:56 +0000 (UTC) X-FDA: 76552642152.16.cover22_626ca3a6ccf24 X-Spam-Summary: 1,0,0,,d41d8cd98f00b204,ying.huang@intel.com,,RULES_HIT:30003:30012:30025:30054:30064:30070,0,RBL:134.134.136.100:@intel.com:.lbl8.mailshell.net-64.95.201.95 62.18.0.100,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:ft,MSBL:0,DNSBL:none,Custom_rules:0:0:0,LFtime:23,LUA_SUMMARY:none X-HE-Tag: cover22_626ca3a6ccf24 X-Filterd-Recvd-Size: 7384 Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by imf41.hostedemail.com (Postfix) with ESMTP for ; Tue, 3 Mar 2020 03:37:56 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 02 Mar 2020 19:37:54 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,509,1574150400"; d="scan'208";a="258229649" Received: from yhuang-dev.sh.intel.com ([10.239.159.23]) by orsmga002.jf.intel.com with ESMTP; 02 Mar 2020 19:37:51 -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: [PATCH] mm: Add PageLayzyFree() helper functions for MADV_FREE Date: Tue, 3 Mar 2020 11:37:38 +0800 Message-Id: <20200303033738.281908-1-ying.huang@intel.com> X-Mailer: git-send-email 2.25.0 MIME-Version: 1.0 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Huang Ying Now PageSwapBacked() is used as the helper function to check whether pages have been freed lazily via MADV_FREE. This isn't very obvious. So Dave suggested to add PageLazyFree() family helper functions 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;