From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751857AbdB0OyC (ORCPT ); Mon, 27 Feb 2017 09:54:02 -0500 Received: from mx2.suse.de ([195.135.220.15]:44073 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751571AbdB0Ox4 (ORCPT ); Mon, 27 Feb 2017 09:53:56 -0500 Date: Mon, 27 Feb 2017 15:53:47 +0100 From: Michal Hocko To: Shaohua Li Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Kernel-team@fb.com, minchan@kernel.org, hughd@google.com, hannes@cmpxchg.org, riel@redhat.com, mgorman@techsingularity.net, akpm@linux-foundation.org Subject: Re: [PATCH V5 3/6] mm: move MADV_FREE pages into LRU_INACTIVE_FILE list Message-ID: <20170227145347.GF26504@dhcp22.suse.cz> References: <2f87063c1e9354677b7618c647abde77b07561e5.1487965799.git.shli@fb.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2f87063c1e9354677b7618c647abde77b07561e5.1487965799.git.shli@fb.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri 24-02-17 13:31:46, Shaohua Li wrote: > madv MADV_FREE indicate pages are 'lazyfree'. They are still anonymous > pages, but they can be freed without pageout. To destinguish them > against normal anonymous pages, we clear their SwapBacked flag. > > MADV_FREE pages could be freed without pageout, so they pretty much like > used once file pages. For such pages, we'd like to reclaim them once > there is memory pressure. Also it might be unfair reclaiming MADV_FREE > pages always before used once file pages and we definitively want to > reclaim the pages before other anonymous and file pages. > > To speed up MADV_FREE pages reclaim, we put the pages into > LRU_INACTIVE_FILE list. The rationale is LRU_INACTIVE_FILE list is tiny > nowadays and should be full of used once file pages. Reclaiming > MADV_FREE pages will not have much interfere of anonymous and active > file pages. And the inactive file pages and MADV_FREE pages will be > reclaimed according to their age, so we don't reclaim too many MADV_FREE > pages too. Putting the MADV_FREE pages into LRU_INACTIVE_FILE_LIST also > means we can reclaim the pages without swap support. This idea is > suggested by Johannes. > > This patch doesn't move MADV_FREE pages to LRU_INACTIVE_FILE list yet to > avoid bisect failure, next patch will do it. This patch also changes behavior of madv_freed pages on the active list because they are not moved to the inactive list but considering how anon pages are reclaimed these days I do not really think this will be noticeable. > The patch is based on Minchan's original patch. > > Cc: Michal Hocko > Cc: Minchan Kim > Cc: Hugh Dickins > Cc: Rik van Riel > Cc: Mel Gorman > Cc: Andrew Morton > Suggested-by: Johannes Weiner > Signed-off-by: Shaohua Li Acked-by: Michal Hocko > --- > include/linux/swap.h | 2 +- > include/linux/vm_event_item.h | 2 +- > mm/huge_memory.c | 3 --- > mm/madvise.c | 2 -- > mm/swap.c | 50 ++++++++++++++++++++++++------------------- > mm/vmstat.c | 1 + > 6 files changed, 31 insertions(+), 29 deletions(-) > > diff --git a/include/linux/swap.h b/include/linux/swap.h > index 45e91dd..486494e 100644 > --- a/include/linux/swap.h > +++ b/include/linux/swap.h > @@ -279,7 +279,7 @@ 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 mark_page_lazyfree(struct page *page); > extern void swap_setup(void); > > extern void add_page_to_unevictable_list(struct page *page); > diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h > index 6aa1b6c..94e58da 100644 > --- a/include/linux/vm_event_item.h > +++ b/include/linux/vm_event_item.h > @@ -25,7 +25,7 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT, > FOR_ALL_ZONES(PGALLOC), > FOR_ALL_ZONES(ALLOCSTALL), > FOR_ALL_ZONES(PGSCAN_SKIP), > - PGFREE, PGACTIVATE, PGDEACTIVATE, > + PGFREE, PGACTIVATE, PGDEACTIVATE, PGLAZYFREE, > PGFAULT, PGMAJFAULT, > PGLAZYFREED, > PGREFILL, > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index cf9fb46..3b7ee0c 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -1562,9 +1562,6 @@ bool madvise_free_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, > ClearPageDirty(page); > unlock_page(page); > > - if (PageActive(page)) > - deactivate_page(page); > - > if (pmd_young(orig_pmd) || pmd_dirty(orig_pmd)) { > orig_pmd = pmdp_huge_get_and_clear_full(tlb->mm, addr, pmd, > tlb->fullmm); > diff --git a/mm/madvise.c b/mm/madvise.c > index dc5927c..61e10b1 100644 > --- a/mm/madvise.c > +++ b/mm/madvise.c > @@ -411,8 +411,6 @@ 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 c4910f1..c4fb4b9 100644 > --- a/mm/swap.c > +++ b/mm/swap.c > @@ -46,7 +46,7 @@ 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); > +static DEFINE_PER_CPU(struct pagevec, lru_lazyfree_pvecs); > #ifdef CONFIG_SMP > static DEFINE_PER_CPU(struct pagevec, activate_page_pvecs); > #endif > @@ -561,20 +561,26 @@ static void lru_deactivate_file_fn(struct page *page, struct lruvec *lruvec, > } > > > -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) && PageActive(page) && !PageUnevictable(page)) { > - int file = page_is_file_cache(page); > - int lru = page_lru_base_type(page); > + if (PageLRU(page) && PageAnon(page) && PageSwapBacked(page) && > + !PageUnevictable(page)) { > + bool active = PageActive(page); > > - del_page_from_lru_list(page, lruvec, lru + LRU_ACTIVE); > + del_page_from_lru_list(page, lruvec, LRU_INACTIVE_ANON + active); > ClearPageActive(page); > ClearPageReferenced(page); > - add_page_to_lru_list(page, lruvec, lru); > + /* > + * lazyfree pages are clean anonymous pages. They have > + * SwapBacked flag cleared to distinguish normal anonymous > + * pages > + */ > + ClearPageSwapBacked(page); > + add_page_to_lru_list(page, lruvec, LRU_INACTIVE_FILE); > > - __count_vm_event(PGDEACTIVATE); > - update_page_reclaim_stat(lruvec, file, 0); > + __count_vm_events(PGLAZYFREE, hpage_nr_pages(page)); > + update_page_reclaim_stat(lruvec, 1, 0); > } > } > > @@ -604,9 +610,9 @@ 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); > + pvec = &per_cpu(lru_lazyfree_pvecs, cpu); > if (pagevec_count(pvec)) > - pagevec_lru_move_fn(pvec, lru_deactivate_fn, NULL); > + pagevec_lru_move_fn(pvec, lru_lazyfree_fn, NULL); > > activate_page_drain(cpu); > } > @@ -638,22 +644,22 @@ void deactivate_file_page(struct page *page) > } > > /** > - * deactivate_page - deactivate a page > + * mark_page_lazyfree - make an anon page lazyfree > * @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. > + * mark_page_lazyfree() moves @page to the inactive file list. > + * 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); > +void mark_page_lazyfree(struct page *page) > + { > + if (PageLRU(page) && PageAnon(page) && PageSwapBacked(page) && > + !PageUnevictable(page)) { > + struct pagevec *pvec = &get_cpu_var(lru_lazyfree_pvecs); > > get_page(page); > if (!pagevec_add(pvec, page) || PageCompound(page)) > - pagevec_lru_move_fn(pvec, lru_deactivate_fn, NULL); > - put_cpu_var(lru_deactivate_pvecs); > + pagevec_lru_move_fn(pvec, lru_lazyfree_fn, NULL); > + put_cpu_var(lru_lazyfree_pvecs); > } > } > > @@ -704,7 +710,7 @@ 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)) || > + pagevec_count(&per_cpu(lru_lazyfree_pvecs, cpu)) || > need_activate_page_drain(cpu)) { > INIT_WORK(work, lru_add_drain_per_cpu); > queue_work_on(cpu, lru_add_drain_wq, work); > diff --git a/mm/vmstat.c b/mm/vmstat.c > index 69f9aff..7774196 100644 > --- a/mm/vmstat.c > +++ b/mm/vmstat.c > @@ -992,6 +992,7 @@ const char * const vmstat_text[] = { > "pgfree", > "pgactivate", > "pgdeactivate", > + "pglazyfree", > > "pgfault", > "pgmajfault", > -- > 2.9.3 > -- Michal Hocko SUSE Labs