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 04E8FC7EE29 for ; Mon, 22 May 2023 12:37:47 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 5F96F900004; Mon, 22 May 2023 08:37:47 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 5A978900003; Mon, 22 May 2023 08:37:47 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4BF49900004; Mon, 22 May 2023 08:37:47 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 3DC01900003 for ; Mon, 22 May 2023 08:37:47 -0400 (EDT) Received: from smtpin26.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id D03BE1C6FCE for ; Mon, 22 May 2023 12:37:46 +0000 (UTC) X-FDA: 80817842532.26.2A1DF70 Received: from out-2.mta1.migadu.com (out-2.mta1.migadu.com [95.215.58.2]) by imf03.hostedemail.com (Postfix) with ESMTP id B9EA720019 for ; Mon, 22 May 2023 12:37:44 +0000 (UTC) Authentication-Results: imf03.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=jXaiovzB; spf=pass (imf03.hostedemail.com: domain of qi.zheng@linux.dev designates 95.215.58.2 as permitted sender) smtp.mailfrom=qi.zheng@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1684759065; 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-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=8Vf55yronjbw4sVFWMpRa3/wf12y9L5bS4sB8okVwQ4=; b=hfeBplK33WinesvE2Vh79T6eIrrcFrb4g1jOLXJN7wDhxpr5BcaIWRLAmm8V0T8xpr3X01 2yBvvIZRIQNa04cDIECS0Gc8fUvyyyEBDnB1Ilo/igU4G16RqmPC9GPblvpxuQbnvR2MKl m2I1tol6FBbRsDJ59zF3trEVdFb5+C8= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1684759065; a=rsa-sha256; cv=none; b=lpLav2KP3htyeD3M4HVL+eWAJ1pKP98mVOGP5Z7vbxHoKonSNUAxFP1BDboUOWABtgqWZl kIFAnE3xMqkjrC7/PwNSYVzjpfzf5IQErMsJidQMDNKQon2GB/PwPUp5replM24jXYRMDY aKQfyViaZmfccLnxiQtGNFPIo3g2+b0= ARC-Authentication-Results: i=1; imf03.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=jXaiovzB; spf=pass (imf03.hostedemail.com: domain of qi.zheng@linux.dev designates 95.215.58.2 as permitted sender) smtp.mailfrom=qi.zheng@linux.dev; dmarc=pass (policy=none) header.from=linux.dev Message-ID: <07317766-c901-34a9-360a-e916db4b9045@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1684759063; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=8Vf55yronjbw4sVFWMpRa3/wf12y9L5bS4sB8okVwQ4=; b=jXaiovzBiCse3JJSew7ABrQpqiKz5q/ZNG2KpsWelvRJoTKqKtEfMjviU4AIEkWIALNHIa kKysD7sKdNbc9KmProLOOQcLCexRdc8wGwbuYN5BCz6J4Jzg4/JZOqmE7pZ2Nv7Capzcto RSdtUQKNc2JoTgSP/J8hXW/Vtmv5SXs= Date: Mon, 22 May 2023 20:37:31 +0800 MIME-Version: 1.0 Subject: Re: [PATCH 17/31] mm/various: give up if pte_offset_map[_lock]() fails Content-Language: en-US To: Hugh Dickins , Andrew Morton Cc: Mike Kravetz , Mike Rapoport , "Kirill A. Shutemov" , Matthew Wilcox , David Hildenbrand , Suren Baghdasaryan , Qi Zheng , Yang Shi , Mel Gorman , Peter Xu , Peter Zijlstra , Will Deacon , Yu Zhao , Alistair Popple , Ralph Campbell , Ira Weiny , Steven Price , SeongJae Park , Naoya Horiguchi , Christophe Leroy , Zack Rusin , Jason Gunthorpe , Axel Rasmussen , Anshuman Khandual , Pasha Tatashin , Miaohe Lin , Minchan Kim , Christoph Hellwig , Song Liu , Thomas Hellstrom , linux-kernel@vger.kernel.org, linux-mm@kvack.org References: <68a97fbe-5c1e-7ac6-72c-7b9c6290b370@google.com> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Qi Zheng In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Rspamd-Queue-Id: B9EA720019 X-Rspam-User: X-Stat-Signature: 445nrjuy7i88dwdwirzyw9rhj14ojcpk X-Rspamd-Server: rspam03 X-HE-Tag: 1684759064-399330 X-HE-Meta: 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 UdFWIAxe xTC8IG8U3lFBe/bCVXkVunJWVQ6tCH+iXuKYEUSCBw3SuG9pciZxIYbfeohKTuLqTNuBSqNQzNyQqaFtzY7hLeSFHglUplKtMabNaUcrADCy1uUM3B2lREYVLlIPcjl5R63erzJVbU3lniK+luUvYfjioGxNUyxSjemKW 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: On 2023/5/22 20:24, Qi Zheng wrote: > > > On 2023/5/22 13:10, Hugh Dickins wrote: >> Following the examples of nearby code, various functions can just give >> up if pte_offset_map() or pte_offset_map_lock() fails.  And there's no >> need for a preliminary pmd_trans_unstable() or other such check, since >> such cases are now safely handled inside. >> >> Signed-off-by: Hugh Dickins >> --- >>   mm/gup.c            | 9 ++++++--- >>   mm/ksm.c            | 7 ++++--- >>   mm/memcontrol.c     | 8 ++++---- >>   mm/memory-failure.c | 8 +++++--- >>   mm/migrate.c        | 3 +++ >>   mm/swap_state.c     | 3 +++ >>   6 files changed, 25 insertions(+), 13 deletions(-) >> > > [...] > >> diff --git a/mm/migrate.c b/mm/migrate.c >> index 3ecb7a40075f..308a56f0b156 100644 >> --- a/mm/migrate.c >> +++ b/mm/migrate.c >> @@ -305,6 +305,9 @@ void migration_entry_wait(struct mm_struct *mm, >> pmd_t *pmd, >>       swp_entry_t entry; >>       ptep = pte_offset_map_lock(mm, pmd, address, &ptl); >> +    if (!ptep) >> +        return; > > Maybe we should return false and let the caller handle the failure. > >> + >>       pte = *ptep; >>       pte_unmap(ptep); >> diff --git a/mm/swap_state.c b/mm/swap_state.c >> index b76a65ac28b3..db2ec85ef332 100644 >> --- a/mm/swap_state.c >> +++ b/mm/swap_state.c >> @@ -734,6 +734,9 @@ static void swap_ra_info(struct vm_fault *vmf, >>       /* Copy the PTEs because the page table may be unmapped */ >>       orig_pte = pte = pte_offset_map(vmf->pmd, faddr); >> +    if (!pte) >> +        return; > > Ditto? Oh, I see that you handle it in the PATCH[22/31]. > >> + >>       if (fpfn == pfn + 1) { >>           lpfn = fpfn; >>           rpfn = fpfn + win; > -- Thanks, Qi