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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 28E74C07E9D for ; Tue, 27 Sep 2022 16:28:23 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B22B18E00E2; Tue, 27 Sep 2022 12:28:22 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id AD1A58E00C1; Tue, 27 Sep 2022 12:28:22 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 973C88E00E2; Tue, 27 Sep 2022 12:28:22 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 872588E00C1 for ; Tue, 27 Sep 2022 12:28:22 -0400 (EDT) Received: from smtpin08.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 396E480FE5 for ; Tue, 27 Sep 2022 16:28:22 +0000 (UTC) X-FDA: 79958398044.08.B797AA7 Received: from mail-pl1-f182.google.com (mail-pl1-f182.google.com [209.85.214.182]) by imf30.hostedemail.com (Postfix) with ESMTP id 9134480017 for ; Tue, 27 Sep 2022 16:28:21 +0000 (UTC) Received: by mail-pl1-f182.google.com with SMTP id v1so9538366plo.9 for ; Tue, 27 Sep 2022 09:28:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date; bh=AsJY41XMXFwgdgJedGBIEW9iEXdmuZaxFchvtZgLRts=; b=m6GcP6wWedee5WJZJaWbkT5RTdd55uan6Np016DjpR8muG6vIptBwf3QzE4ERNpttX affNl+gUFcSzOYXosWJ/VRNjxYXy6FJfUHO5liFb7f0D5IstX1F597GLJSGrDA7jLhUD agxRfB3pWC7X6zWYvj7pwv0ePgUXr9cf1klPUuTHnNmaQhlQA0/PzaK0mKwVXiZUPXMj OZSsmozTQGpDPKL7eaUGXjsln2FL4L4E1wk/WU0AWbsxNpjOvcdECApM3/JSfUfxUR1B /ivlVLd+zH8EmphX+KW4fYQo4eRP8Tu2zNIh1l1qyg+uW8hsnnAiVXXZYMF2KwGSTiBq rHnA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date; bh=AsJY41XMXFwgdgJedGBIEW9iEXdmuZaxFchvtZgLRts=; b=msFbZqvOw3+/GX+kyaPkMtgNig1ptxqoxGrVJNNDfEZE59CO3U4c4gdQc8ncnK6rM1 PB1XbVrr+bA3Ub5/bx4mevjxQg8OW1bN6eOY6W73S8IX4QeGSpAGQ0MdgvdRujDX/8rI oKWLA/MP7Iv/FnMoNOT/Rp6OUzSbL6JYdz+wqJG9RIcURYJioSpFGz5MB8Ay+MspfGNU N1mJeUPuwD4w+0f1U5jXlTXi/hO9aLClCwHJwUn8pUCNgjRQl5c0zIAyAk7r5GT/27vx DSUQKb2UzSkUPqCfqbMrMp4KjHy/KVQ5SGTh5bATLEn/fskaAHTblADe3jQ7YT/pDAq/ r2Mg== X-Gm-Message-State: ACrzQf2EhtrtuPvPQaQq4lMZJuKYkfqGPBMIAGTsFT7Ji0dyhen7gq7w uIZGXiZSlPaNQkN8Oag4XRY= X-Google-Smtp-Source: AMsMyM718HLi2PtSjot1gUUVGevKickODf7v55QPmyvyloREZ18G25HdbEpAcyTcqIr1Rfcie5ZhUg== X-Received: by 2002:a17:90b:3e86:b0:205:d88c:616d with SMTP id rj6-20020a17090b3e8600b00205d88c616dmr4387498pjb.78.1664296100553; Tue, 27 Sep 2022 09:28:20 -0700 (PDT) Received: from archlinux.localdomain ([140.121.198.213]) by smtp.googlemail.com with ESMTPSA id 9-20020a17090a0f0900b001f333fab3d6sm8602360pjy.18.2022.09.27.09.28.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 27 Sep 2022 09:28:19 -0700 (PDT) From: Chih-En Lin To: Andrew Morton , Qi Zheng , David Hildenbrand , Matthew Wilcox , Christophe Leroy Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Luis Chamberlain , Kees Cook , Iurii Zaikin , Vlastimil Babka , William Kucharski , "Kirill A . Shutemov" , Peter Xu , Suren Baghdasaryan , Arnd Bergmann , Tong Tiangen , Pasha Tatashin , Li kunyu , Nadav Amit , Anshuman Khandual , Minchan Kim , Yang Shi , Song Liu , Miaohe Lin , Thomas Gleixner , Sebastian Andrzej Siewior , Andy Lutomirski , Fenghua Yu , Dinglan Peng , Pedro Fonseca , Jim Huang , Huichun Feng , Chih-En Lin Subject: [RFC PATCH v2 8/9] mm: Handle COW PTE with reclaim algorithm Date: Wed, 28 Sep 2022 00:29:56 +0800 Message-Id: <20220927162957.270460-9-shiyn.lin@gmail.com> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20220927162957.270460-1-shiyn.lin@gmail.com> References: <20220927162957.270460-1-shiyn.lin@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1664296101; a=rsa-sha256; cv=none; b=jweZMZ3ujlJ/7NNxbcyPvMzCHvr1L7fMFmtX42JSdUjVORrC2PTj/cZZeAo9LPfYoffKwv ob1VPMEXijDcVueUSJsGdSGryEEzgCS1BB0FNdqchtinDPDOiCjDSrT+vvrifgIu7NgQtB zfzeOzYfRnZhacCYd4PnFOCouMKRnHU= ARC-Authentication-Results: i=1; imf30.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=m6GcP6wW; spf=pass (imf30.hostedemail.com: domain of shiyn.lin@gmail.com designates 209.85.214.182 as permitted sender) smtp.mailfrom=shiyn.lin@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1664296101; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=AsJY41XMXFwgdgJedGBIEW9iEXdmuZaxFchvtZgLRts=; b=K/6mRRE6RNzKak20d9ZtHcLsaWyErW3PLNilUz+MwgusOgCBLpteqCV++ifSjj3WhvJYFc d1+M1ELuf/JL1xGAzARE5zZI4wLgVRVtL62RED5nHZG+aM5DBsSW83+w3Lk3q94FnoPOz/ teyrbUUEheAxjr5zZ3Xw0yFX7nDGa4s= X-Stat-Signature: 5cfz4ziadrfqwpjpchoo5i9dbnyaz8nd X-Rspamd-Queue-Id: 9134480017 X-Rspam-User: Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=m6GcP6wW; spf=pass (imf30.hostedemail.com: domain of shiyn.lin@gmail.com designates 209.85.214.182 as permitted sender) smtp.mailfrom=shiyn.lin@gmail.com; dmarc=pass (policy=none) header.from=gmail.com X-Rspamd-Server: rspam01 X-HE-Tag: 1664296101-431261 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: To avoid the PFRA reclaiming the page resided in the COWed PTE table, break COW when it using rmap to unmap all the processes. Signed-off-by: Chih-En Lin --- include/linux/rmap.h | 2 ++ mm/page_vma_mapped.c | 5 +++++ mm/rmap.c | 2 +- mm/swapfile.c | 1 + mm/vmscan.c | 1 + 5 files changed, 10 insertions(+), 1 deletion(-) diff --git a/include/linux/rmap.h b/include/linux/rmap.h index b89b4b86951f8..5c7e3bedc068b 100644 --- a/include/linux/rmap.h +++ b/include/linux/rmap.h @@ -312,6 +312,8 @@ int make_device_exclusive_range(struct mm_struct *mm, unsigned long start, #define PVMW_SYNC (1 << 0) /* Look for migration entries rather than present PTEs */ #define PVMW_MIGRATION (1 << 1) +/* Break COW PTE during the walking */ +#define PVMW_COW_PTE (1 << 2) struct page_vma_mapped_walk { unsigned long pfn; diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c index 8e9e574d535aa..5008957bbe4a7 100644 --- a/mm/page_vma_mapped.c +++ b/mm/page_vma_mapped.c @@ -251,6 +251,11 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw) step_forward(pvmw, PMD_SIZE); continue; } + + /* TODO: Does breaking COW PTE here is correct? */ + if (pvmw->flags & PVMW_COW_PTE) + handle_cow_pte(vma, pvmw->pmd, pvmw->address, false); + if (!map_pte(pvmw)) goto next_pte; this_pte: diff --git a/mm/rmap.c b/mm/rmap.c index 93d5a6f793d20..8f737cb44e48a 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1477,7 +1477,7 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma, unsigned long address, void *arg) { struct mm_struct *mm = vma->vm_mm; - DEFINE_FOLIO_VMA_WALK(pvmw, folio, vma, address, 0); + DEFINE_FOLIO_VMA_WALK(pvmw, folio, vma, address, PVMW_COW_PTE); pte_t pteval; struct page *subpage; bool anon_exclusive, ret = true; diff --git a/mm/swapfile.c b/mm/swapfile.c index 1fdccd2f1422e..ef4d3d81a824b 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -1916,6 +1916,7 @@ static inline int unuse_pmd_range(struct vm_area_struct *vma, pud_t *pud, do { cond_resched(); next = pmd_addr_end(addr, end); + handle_cow_pte(vma, pmd, addr, false); if (pmd_none_or_trans_huge_or_clear_bad(pmd)) continue; ret = unuse_pte_range(vma, pmd, addr, next, type); diff --git a/mm/vmscan.c b/mm/vmscan.c index b2b1431352dcd..030fad3d310d9 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1822,6 +1822,7 @@ static unsigned int shrink_page_list(struct list_head *page_list, /* * The folio is mapped into the page tables of one or more * processes. Try to unmap it here. + * It will write to the page tables, break COW PTE here. */ if (folio_mapped(folio)) { enum ttu_flags flags = TTU_BATCH_FLUSH; -- 2.37.3