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=-3.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 221DBC433E0 for ; Wed, 3 Jun 2020 23:00:27 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id CC1C520B80 for ; Wed, 3 Jun 2020 23:00:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="GSLR7Szb" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CC1C520B80 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 778EB280047; Wed, 3 Jun 2020 19:00:26 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 729B4280003; Wed, 3 Jun 2020 19:00:26 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6664C280047; Wed, 3 Jun 2020 19:00:26 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0224.hostedemail.com [216.40.44.224]) by kanga.kvack.org (Postfix) with ESMTP id 49EE1280003 for ; Wed, 3 Jun 2020 19:00:26 -0400 (EDT) Received: from smtpin25.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 108B31EE6 for ; Wed, 3 Jun 2020 23:00:26 +0000 (UTC) X-FDA: 76889421252.25.stone04_20d156e972d4c Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin25.hostedemail.com (Postfix) with ESMTP id E2E2D1804E3A0 for ; Wed, 3 Jun 2020 23:00:25 +0000 (UTC) X-HE-Tag: stone04_20d156e972d4c X-Filterd-Recvd-Size: 9021 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf20.hostedemail.com (Postfix) with ESMTP for ; Wed, 3 Jun 2020 23:00:25 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 41536208E4; Wed, 3 Jun 2020 23:00:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591225224; bh=0TgDIPU4/9+dHAyBxn7+RfgrqRWvoEu2Jsw3p2Rw59g=; h=Date:From:To:Subject:In-Reply-To:From; b=GSLR7Szbg4x4B4rU74rIj2Ew4lPWBVw9QhmiP0yEZRD/aEZzrKXrZyuQS5tP1rGWb usaqjOoNtnFqyNvgd/zg4n7Iuv44dyh9IKnm+yv6MRzs/80dWEfeLBq6EaVhyQOv6i 4skdoaRFEWDD89h4RCs9WCaChe/KozgYGVDNTtD0= Date: Wed, 03 Jun 2020 16:00:23 -0700 From: Andrew Morton To: aarcange@redhat.com, akpm@linux-foundation.org, jhubbard@nvidia.com, kirill.shutemov@linux.intel.com, linux-mm@kvack.org, mike.kravetz@oracle.com, mm-commits@vger.kernel.org, rcampbell@nvidia.com, torvalds@linux-foundation.org, william.kucharski@oracle.com, yang.shi@linux.alibaba.com, ziy@nvidia.com Subject: [patch 066/131] khugepaged: allow to collapse PTE-mapped compound pages Message-ID: <20200603230023.ZyVnewr_F%akpm@linux-foundation.org> In-Reply-To: <20200603155549.e041363450869eaae4c7f05b@linux-foundation.org> User-Agent: s-nail v14.8.16 X-Rspamd-Queue-Id: E2E2D1804E3A0 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam03 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: "Kirill A. Shutemov" Subject: khugepaged: allow to collapse PTE-mapped compound pages We can collapse PTE-mapped compound pages. We only need to avoid handling them more than once: lock/unlock page only once if it's present in the PMD range multiple times as it handled on compound level. The same goes for LRU isolation and putback. Link: http://lkml.kernel.org/r/20200416160026.16538-7-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov Reviewed-by: William Kucharski Reviewed-by: Zi Yan Tested-by: Zi Yan Acked-by: Yang Shi Cc: Andrea Arcangeli Cc: John Hubbard Cc: Mike Kravetz Cc: Ralph Campbell Signed-off-by: Andrew Morton --- mm/khugepaged.c | 99 ++++++++++++++++++++++++++++++---------------- 1 file changed, 65 insertions(+), 34 deletions(-) --- a/mm/khugepaged.c~khugepaged-allow-to-collapse-pte-mapped-compound-pages +++ a/mm/khugepaged.c @@ -512,17 +512,30 @@ void __khugepaged_exit(struct mm_struct static void release_pte_page(struct page *page) { - dec_node_page_state(page, NR_ISOLATED_ANON + page_is_file_lru(page)); + mod_node_page_state(page_pgdat(page), + NR_ISOLATED_ANON + page_is_file_lru(page), + -compound_nr(page)); unlock_page(page); putback_lru_page(page); } -static void release_pte_pages(pte_t *pte, pte_t *_pte) +static void release_pte_pages(pte_t *pte, pte_t *_pte, + struct list_head *compound_pagelist) { + struct page *page, *tmp; + while (--_pte >= pte) { pte_t pteval = *_pte; - if (!pte_none(pteval) && !is_zero_pfn(pte_pfn(pteval))) - release_pte_page(pte_page(pteval)); + + page = pte_page(pteval); + if (!pte_none(pteval) && !is_zero_pfn(pte_pfn(pteval)) && + !PageCompound(page)) + release_pte_page(page); + } + + list_for_each_entry_safe(page, tmp, compound_pagelist, lru) { + list_del(&page->lru); + release_pte_page(page); } } @@ -539,7 +552,8 @@ static bool is_refcount_suitable(struct static int __collapse_huge_page_isolate(struct vm_area_struct *vma, unsigned long address, - pte_t *pte) + pte_t *pte, + struct list_head *compound_pagelist) { struct page *page = NULL; pte_t *_pte; @@ -569,13 +583,21 @@ static int __collapse_huge_page_isolate( goto out; } - /* TODO: teach khugepaged to collapse THP mapped with pte */ + VM_BUG_ON_PAGE(!PageAnon(page), page); + if (PageCompound(page)) { - result = SCAN_PAGE_COMPOUND; - goto out; - } + struct page *p; + page = compound_head(page); - VM_BUG_ON_PAGE(!PageAnon(page), page); + /* + * Check if we have dealt with the compound page + * already + */ + list_for_each_entry(p, compound_pagelist, lru) { + if (page == p) + goto next; + } + } /* * We can do it before isolate_lru_page because the @@ -604,19 +626,15 @@ static int __collapse_huge_page_isolate( result = SCAN_PAGE_COUNT; goto out; } - if (pte_write(pteval)) { - writable = true; - } else { - if (PageSwapCache(page) && - !reuse_swap_page(page, NULL)) { - unlock_page(page); - result = SCAN_SWAP_CACHE_PAGE; - goto out; - } + if (!pte_write(pteval) && PageSwapCache(page) && + !reuse_swap_page(page, NULL)) { /* - * Page is not in the swap cache. It can be collapsed - * into a THP. + * Page is in the swap cache and cannot be re-used. + * It cannot be collapsed into a THP. */ + unlock_page(page); + result = SCAN_SWAP_CACHE_PAGE; + goto out; } /* @@ -628,16 +646,23 @@ static int __collapse_huge_page_isolate( result = SCAN_DEL_PAGE_LRU; goto out; } - inc_node_page_state(page, - NR_ISOLATED_ANON + page_is_file_lru(page)); + mod_node_page_state(page_pgdat(page), + NR_ISOLATED_ANON + page_is_file_lru(page), + compound_nr(page)); VM_BUG_ON_PAGE(!PageLocked(page), page); VM_BUG_ON_PAGE(PageLRU(page), page); + if (PageCompound(page)) + list_add_tail(&page->lru, compound_pagelist); +next: /* There should be enough young pte to collapse the page */ if (pte_young(pteval) || page_is_young(page) || PageReferenced(page) || mmu_notifier_test_young(vma->vm_mm, address)) referenced++; + + if (pte_write(pteval)) + writable = true; } if (likely(writable)) { if (likely(referenced)) { @@ -651,7 +676,7 @@ static int __collapse_huge_page_isolate( } out: - release_pte_pages(pte, _pte); + release_pte_pages(pte, _pte, compound_pagelist); trace_mm_collapse_huge_page_isolate(page, none_or_zero, referenced, writable, result); return 0; @@ -660,13 +685,14 @@ out: static void __collapse_huge_page_copy(pte_t *pte, struct page *page, struct vm_area_struct *vma, unsigned long address, - spinlock_t *ptl) + spinlock_t *ptl, + struct list_head *compound_pagelist) { + struct page *src_page, *tmp; pte_t *_pte; for (_pte = pte; _pte < pte + HPAGE_PMD_NR; _pte++, page++, address += PAGE_SIZE) { pte_t pteval = *_pte; - struct page *src_page; if (pte_none(pteval) || is_zero_pfn(pte_pfn(pteval))) { clear_user_highpage(page, address); @@ -686,7 +712,8 @@ static void __collapse_huge_page_copy(pt } else { src_page = pte_page(pteval); copy_user_highpage(page, src_page, address, vma); - release_pte_page(src_page); + if (!PageCompound(src_page)) + release_pte_page(src_page); /* * ptl mostly unnecessary, but preempt has to * be disabled to update the per-cpu stats @@ -703,6 +730,11 @@ static void __collapse_huge_page_copy(pt free_page_and_swap_cache(src_page); } } + + list_for_each_entry_safe(src_page, tmp, compound_pagelist, lru) { + list_del(&src_page->lru); + release_pte_page(src_page); + } } static void khugepaged_alloc_sleep(void) @@ -961,6 +993,7 @@ static void collapse_huge_page(struct mm struct page **hpage, int node, int referenced, int unmapped) { + LIST_HEAD(compound_pagelist); pmd_t *pmd, _pmd; pte_t *pte; pgtable_t pgtable; @@ -1061,7 +1094,8 @@ static void collapse_huge_page(struct mm mmu_notifier_invalidate_range_end(&range); spin_lock(pte_ptl); - isolated = __collapse_huge_page_isolate(vma, address, pte); + isolated = __collapse_huge_page_isolate(vma, address, pte, + &compound_pagelist); spin_unlock(pte_ptl); if (unlikely(!isolated)) { @@ -1086,7 +1120,8 @@ static void collapse_huge_page(struct mm */ anon_vma_unlock_write(vma->anon_vma); - __collapse_huge_page_copy(pte, new_page, vma, address, pte_ptl); + __collapse_huge_page_copy(pte, new_page, vma, address, pte_ptl, + &compound_pagelist); pte_unmap(pte); __SetPageUptodate(new_page); pgtable = pmd_pgtable(_pmd); @@ -1205,11 +1240,7 @@ static int khugepaged_scan_pmd(struct mm goto out_unmap; } - /* TODO: teach khugepaged to collapse THP mapped with pte */ - if (PageCompound(page)) { - result = SCAN_PAGE_COMPOUND; - goto out_unmap; - } + page = compound_head(page); /* * Record which node the original page is from and save this _