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=-9.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,T_DKIMWL_WL_HIGH,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 9AD4AC282DD for ; Mon, 10 Jun 2019 11:13:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 54C42208E3 for ; Mon, 10 Jun 2019 11:13:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560165216; bh=byRx5Dt5zmak1RFVWT6YJH7O5F4SoCFatjtO/QRgf9w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=eZbb2KJ3Cw0P3mPQ93OiY8H3+WOCuk6sLl1oxvRuGXH3fyoIQoTj5iRPMwq+u6j76 3PTge7EBh9KG/O71CUtyqDJm5crI143CK11GbgNhjxcA44woUmpbiSQbksvG8sVIJn yI90+BDAK96s+OTKdxYV8TD7q0EgEtqcS98l97p0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389707AbfFJLNf (ORCPT ); Mon, 10 Jun 2019 07:13:35 -0400 Received: from mail-pf1-f193.google.com ([209.85.210.193]:46062 "EHLO mail-pf1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388570AbfFJLNe (ORCPT ); Mon, 10 Jun 2019 07:13:34 -0400 Received: by mail-pf1-f193.google.com with SMTP id s11so5101383pfm.12; Mon, 10 Jun 2019 04:13:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=rPG+ROWOzHjK16mIcQ4C+hvTtB/BQwTOXkhzxALsNDM=; b=NmKhfQn2/0M7QiWafaLEoMeyTHABnSvZPFy8O2V0AL4u+lJgz3njJVO5H5zxGzSy4h xqy2KzD/DPsBMirf/T36qYm88jTFj8X6yvNuTsL1Bi5EzG+aT6xZ3Iuqua1UWhM+k0yO GKY2t/Fyiv9LwekT+YjjHt3Sp5yhJKexKC6lqjeGNtd6uVcz0EntdyZo6eFsoNTHjVQX uu12cLDdBNqTnwdJib0hsQJdAgoElWA9sdMeGjxMzFwrJywj8p6yYGc+mjPf2MrEQ8DK jjyRMG/Vyt0JFVhWG1IBivNsQnuK1M/mpK5CR5Iu+DnuKJ8+3YdEGPIafurC55SsJ7PA We0w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-transfer-encoding; bh=rPG+ROWOzHjK16mIcQ4C+hvTtB/BQwTOXkhzxALsNDM=; b=TSNFuYJnpKE8QsTiDOn1IyuZ0iAObReFpgaL+rspuPqBRR84DNeYCgnevaDe0t37c7 eCTNphI4lJIbagI+I9mgOfW6YkYl6MCqrullb3w+pB+V8q0+HUcSHTLrykf40EwFSENj X3NZPHLP8nIi/N+/KRbdn0TxcT6wqvipnOR2OPnwHkTQ4N2KkH0SsWl6Du9/NCrkE/rO Ulrhw0aoqETsoN2ELzod+pU1gIMxuNAZdbA6udgBHSU11VHUi8CLAOK556h/QV9uGBXp IIROFLAOCiDBpe8ZIWiR7ltpCNtlZmsO5SFDZtj3EbLpdrfv3PdhATv5zB0cDYSuDpgl IoIQ== X-Gm-Message-State: APjAAAXfTP7zliQw/CYDBZtMv37OgoeMduPxsQGqdxizVXS4TIYGDb78 4saseAx7emlj/et2Xfj1KIA= X-Google-Smtp-Source: APXvYqzY4WtiEyc3qVwXA80Fry7VpC5HipNq59JihUKhfrGRMamA0pPT4cEFDQGwJD6Cz7sjB8iumw== X-Received: by 2002:aa7:8193:: with SMTP id g19mr67599446pfi.162.1560165213314; Mon, 10 Jun 2019 04:13:33 -0700 (PDT) Received: from bbox-2.seo.corp.google.com ([2401:fa00:d:0:98f1:8b3d:1f37:3e8]) by smtp.gmail.com with ESMTPSA id h14sm9224633pgj.8.2019.06.10.04.13.27 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Mon, 10 Jun 2019 04:13:32 -0700 (PDT) From: Minchan Kim To: Andrew Morton Cc: linux-mm , LKML , linux-api@vger.kernel.org, Michal Hocko , Johannes Weiner , Tim Murray , Joel Fernandes , Suren Baghdasaryan , Daniel Colascione , Shakeel Butt , Sonny Rao , Brian Geffon , jannh@google.com, oleg@redhat.com, christian@brauner.io, oleksandr@redhat.com, hdanton@sina.com, lizeb@google.com, Minchan Kim , "Kirill A. Shutemov" , Christopher Lameter Subject: [PATCH v2 5/5] mm: factor out pmd young/dirty bit handling and THP split Date: Mon, 10 Jun 2019 20:12:52 +0900 Message-Id: <20190610111252.239156-6-minchan@kernel.org> X-Mailer: git-send-email 2.22.0.rc2.383.gf4fbbf30c2-goog In-Reply-To: <20190610111252.239156-1-minchan@kernel.org> References: <20190610111252.239156-1-minchan@kernel.org> 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 Now, there are common part among MADV_COLD|PAGEOUT|FREE to reset access/dirty bit resetting or split the THP page to handle part of subpages in the THP page. This patch factor out the common part. Cc: "Kirill A. Shutemov" Cc: Christopher Lameter Signed-off-by: Minchan Kim --- include/linux/huge_mm.h | 3 - mm/huge_memory.c | 74 ------------- mm/madvise.c | 234 +++++++++++++++++++++++----------------- 3 files changed, 135 insertions(+), 176 deletions(-) diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index 7cd5c150c21d..2667e1aa3ce5 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -29,9 +29,6 @@ extern struct page *follow_trans_huge_pmd(struct vm_area_struct *vma, unsigned long addr, pmd_t *pmd, unsigned int flags); -extern bool madvise_free_huge_pmd(struct mmu_gather *tlb, - struct vm_area_struct *vma, - pmd_t *pmd, unsigned long addr, unsigned long next); extern int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, pmd_t *pmd, unsigned long addr); diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 9f8bce9a6b32..22e20f929463 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1668,80 +1668,6 @@ vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf, pmd_t pmd) return 0; } -/* - * Return true if we do MADV_FREE successfully on entire pmd page. - * Otherwise, return false. - */ -bool madvise_free_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, - pmd_t *pmd, unsigned long addr, unsigned long next) -{ - spinlock_t *ptl; - pmd_t orig_pmd; - struct page *page; - struct mm_struct *mm = tlb->mm; - bool ret = false; - - tlb_change_page_size(tlb, HPAGE_PMD_SIZE); - - ptl = pmd_trans_huge_lock(pmd, vma); - if (!ptl) - goto out_unlocked; - - orig_pmd = *pmd; - if (is_huge_zero_pmd(orig_pmd)) - goto out; - - if (unlikely(!pmd_present(orig_pmd))) { - VM_BUG_ON(thp_migration_supported() && - !is_pmd_migration_entry(orig_pmd)); - goto out; - } - - page = pmd_page(orig_pmd); - /* - * If other processes are mapping this page, we couldn't discard - * the page unless they all do MADV_FREE so let's skip the page. - */ - if (page_mapcount(page) != 1) - goto out; - - if (!trylock_page(page)) - goto out; - - /* - * If user want to discard part-pages of THP, split it so MADV_FREE - * will deactivate only them. - */ - if (next - addr != HPAGE_PMD_SIZE) { - get_page(page); - spin_unlock(ptl); - split_huge_page(page); - unlock_page(page); - put_page(page); - goto out_unlocked; - } - - if (PageDirty(page)) - ClearPageDirty(page); - unlock_page(page); - - if (pmd_young(orig_pmd) || pmd_dirty(orig_pmd)) { - pmdp_invalidate(vma, addr, pmd); - orig_pmd = pmd_mkold(orig_pmd); - orig_pmd = pmd_mkclean(orig_pmd); - - set_pmd_at(mm, addr, pmd, orig_pmd); - tlb_remove_pmd_tlb_entry(tlb, pmd, addr); - } - - mark_page_lazyfree(page); - ret = true; -out: - spin_unlock(ptl); -out_unlocked: - return ret; -} - static inline void zap_deposited_table(struct mm_struct *mm, pmd_t *pmd) { pgtable_t pgtable; diff --git a/mm/madvise.c b/mm/madvise.c index 3b9d2ba421b1..bb1906bb75fd 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -310,6 +310,91 @@ static long madvise_willneed(struct vm_area_struct *vma, return 0; } +enum madv_pmdp_reset_t { + MADV_PMDP_RESET, /* pmd was reset successfully */ + MADV_PMDP_SPLIT, /* pmd was split */ + MADV_PMDP_ERROR, +}; + +static enum madv_pmdp_reset_t madvise_pmdp_reset_or_split(struct mm_walk *walk, + pmd_t *pmd, spinlock_t *ptl, + unsigned long addr, unsigned long end, + bool young, bool dirty) +{ + pmd_t orig_pmd; + unsigned long next; + struct page *page; + struct mmu_gather *tlb = walk->private; + struct mm_struct *mm = walk->mm; + struct vm_area_struct *vma = walk->vma; + bool reset_young = false; + bool reset_dirty = false; + enum madv_pmdp_reset_t ret = MADV_PMDP_ERROR; + + orig_pmd = *pmd; + if (is_huge_zero_pmd(orig_pmd)) + return ret; + + if (unlikely(!pmd_present(orig_pmd))) { + VM_BUG_ON(thp_migration_supported() && + !is_pmd_migration_entry(orig_pmd)); + return ret; + } + + next = pmd_addr_end(addr, end); + page = pmd_page(orig_pmd); + if (next - addr != HPAGE_PMD_SIZE) { + /* + * THP collapsing is not cheap so only split the page is + * private to the this process. + */ + if (page_mapcount(page) != 1) + return ret; + get_page(page); + spin_unlock(ptl); + lock_page(page); + if (!split_huge_page(page)) + ret = MADV_PMDP_SPLIT; + unlock_page(page); + put_page(page); + return ret; + } + + if (young && pmd_young(orig_pmd)) + reset_young = true; + if (dirty && pmd_dirty(orig_pmd)) + reset_dirty = true; + + /* + * Other process could rely on the PG_dirty for data consistency, + * not pte_dirty so we could reset PG_dirty only when we are owner + * of the page. + */ + if (reset_dirty) { + if (page_mapcount(page) != 1) + goto out; + if (!trylock_page(page)) + goto out; + if (PageDirty(page)) + ClearPageDirty(page); + unlock_page(page); + } + + ret = MADV_PMDP_RESET; + if (reset_young || reset_dirty) { + tlb_change_page_size(tlb, HPAGE_PMD_SIZE); + pmdp_invalidate(vma, addr, pmd); + if (reset_young) + orig_pmd = pmd_mkold(orig_pmd); + if (reset_dirty) + orig_pmd = pmd_mkclean(orig_pmd); + set_pmd_at(mm, addr, pmd, orig_pmd); + tlb_remove_pmd_tlb_entry(tlb, pmd, addr); + } +out: + return ret; +} + static int madvise_cold_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, struct mm_walk *walk) { @@ -319,64 +404,31 @@ static int madvise_cold_pte_range(pmd_t *pmd, unsigned long addr, pte_t *orig_pte, *pte, ptent; spinlock_t *ptl; struct page *page; - unsigned long next; - next = pmd_addr_end(addr, end); if (pmd_trans_huge(*pmd)) { - pmd_t orig_pmd; - - tlb_change_page_size(tlb, HPAGE_PMD_SIZE); ptl = pmd_trans_huge_lock(pmd, vma); if (!ptl) return 0; - orig_pmd = *pmd; - if (is_huge_zero_pmd(orig_pmd)) - goto huge_unlock; - - if (unlikely(!pmd_present(orig_pmd))) { - VM_BUG_ON(thp_migration_supported() && - !is_pmd_migration_entry(orig_pmd)); - goto huge_unlock; - } - - page = pmd_page(orig_pmd); - if (next - addr != HPAGE_PMD_SIZE) { - int err; - - if (page_mapcount(page) != 1) - goto huge_unlock; - - get_page(page); + switch (madvise_pmdp_reset_or_split(walk, pmd, ptl, addr, end, + true, false)) { + case MADV_PMDP_RESET: spin_unlock(ptl); - lock_page(page); - err = split_huge_page(page); - unlock_page(page); - put_page(page); - if (!err) - goto regular_page; - return 0; - } - - if (pmd_young(orig_pmd)) { - pmdp_invalidate(vma, addr, pmd); - orig_pmd = pmd_mkold(orig_pmd); - - set_pmd_at(mm, addr, pmd, orig_pmd); - tlb_remove_pmd_tlb_entry(tlb, pmd, addr); + page = pmd_page(*pmd); + test_and_clear_page_young(page); + deactivate_page(page); + goto next; + case MADV_PMDP_ERROR: + spin_unlock(ptl); + goto next; + case MADV_PMDP_SPLIT: + ; /* go through */ } - - test_and_clear_page_young(page); - deactivate_page(page); -huge_unlock: - spin_unlock(ptl); - return 0; } if (pmd_trans_unstable(pmd)) return 0; -regular_page: tlb_change_page_size(tlb, PAGE_SIZE); orig_pte = pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); flush_tlb_batched_pending(mm); @@ -414,6 +466,7 @@ static int madvise_cold_pte_range(pmd_t *pmd, unsigned long addr, arch_enter_lazy_mmu_mode(); pte_unmap_unlock(orig_pte, ptl); +next: cond_resched(); return 0; @@ -464,70 +517,38 @@ static int madvise_pageout_pte_range(pmd_t *pmd, unsigned long addr, LIST_HEAD(page_list); struct page *page; int isolated = 0; - unsigned long next; if (fatal_signal_pending(current)) return -EINTR; - next = pmd_addr_end(addr, end); if (pmd_trans_huge(*pmd)) { - pmd_t orig_pmd; - - tlb_change_page_size(tlb, HPAGE_PMD_SIZE); ptl = pmd_trans_huge_lock(pmd, vma); if (!ptl) return 0; - orig_pmd = *pmd; - if (is_huge_zero_pmd(orig_pmd)) - goto huge_unlock; - - if (unlikely(!pmd_present(orig_pmd))) { - VM_BUG_ON(thp_migration_supported() && - !is_pmd_migration_entry(orig_pmd)); - goto huge_unlock; - } - - page = pmd_page(orig_pmd); - if (next - addr != HPAGE_PMD_SIZE) { - int err; - - if (page_mapcount(page) != 1) - goto huge_unlock; - get_page(page); + switch (madvise_pmdp_reset_or_split(walk, pmd, ptl, addr, end, + true, false)) { + case MADV_PMDP_RESET: + page = pmd_page(*pmd); spin_unlock(ptl); - lock_page(page); - err = split_huge_page(page); - unlock_page(page); - put_page(page); - if (!err) - goto regular_page; - return 0; - } - - if (isolate_lru_page(page)) - goto huge_unlock; - - if (pmd_young(orig_pmd)) { - pmdp_invalidate(vma, addr, pmd); - orig_pmd = pmd_mkold(orig_pmd); - - set_pmd_at(mm, addr, pmd, orig_pmd); - tlb_remove_tlb_entry(tlb, pmd, addr); + if (isolate_lru_page(page)) + return 0; + ClearPageReferenced(page); + test_and_clear_page_young(page); + list_add(&page->lru, &page_list); + reclaim_pages(&page_list); + goto next; + case MADV_PMDP_ERROR: + spin_unlock(ptl); + goto next; + case MADV_PMDP_SPLIT: + ; /* go through */ } - - ClearPageReferenced(page); - test_and_clear_page_young(page); - list_add(&page->lru, &page_list); -huge_unlock: - spin_unlock(ptl); - reclaim_pages(&page_list); - return 0; } if (pmd_trans_unstable(pmd)) return 0; -regular_page: + tlb_change_page_size(tlb, PAGE_SIZE); orig_pte = pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); flush_tlb_batched_pending(mm); @@ -569,6 +590,7 @@ static int madvise_pageout_pte_range(pmd_t *pmd, unsigned long addr, arch_leave_lazy_mmu_mode(); pte_unmap_unlock(orig_pte, ptl); reclaim_pages(&page_list); +next: cond_resched(); return 0; @@ -620,12 +642,26 @@ static int madvise_free_pte_range(pmd_t *pmd, unsigned long addr, pte_t *orig_pte, *pte, ptent; struct page *page; int nr_swap = 0; - unsigned long next; - next = pmd_addr_end(addr, end); - if (pmd_trans_huge(*pmd)) - if (madvise_free_huge_pmd(tlb, vma, pmd, addr, next)) + if (pmd_trans_huge(*pmd)) { + ptl = pmd_trans_huge_lock(pmd, vma); + if (!ptl) + return 0; + + switch (madvise_pmdp_reset_or_split(walk, pmd, ptl, addr, end, + true, true)) { + case MADV_PMDP_RESET: + page = pmd_page(*pmd); + spin_unlock(ptl); + mark_page_lazyfree(page); goto next; + case MADV_PMDP_ERROR: + spin_unlock(ptl); + goto next; + case MADV_PMDP_SPLIT: + ; /* go through */ + } + } if (pmd_trans_unstable(pmd)) return 0; @@ -737,8 +773,8 @@ static int madvise_free_pte_range(pmd_t *pmd, unsigned long addr, } arch_leave_lazy_mmu_mode(); pte_unmap_unlock(orig_pte, ptl); - cond_resched(); next: + cond_resched(); return 0; } -- 2.22.0.rc2.383.gf4fbbf30c2-goog