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=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 6883DC433DB for ; Mon, 15 Mar 2021 13:04:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1CF4264E99 for ; Mon, 15 Mar 2021 13:04:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229815AbhCONEC (ORCPT ); Mon, 15 Mar 2021 09:04:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60768 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229808AbhCONDx (ORCPT ); Mon, 15 Mar 2021 09:03:53 -0400 Received: from mail-lj1-x236.google.com (mail-lj1-x236.google.com [IPv6:2a00:1450:4864:20::236]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D7B4DC06175F for ; Mon, 15 Mar 2021 06:03:52 -0700 (PDT) Received: by mail-lj1-x236.google.com with SMTP id u10so4649390lju.7 for ; Mon, 15 Mar 2021 06:03:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=shutemov-name.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=/qOUfo30PmDfy59I8NSJRneNR2Umpzy9YtVUdna4m5M=; b=qIqESwX8UcVPz/tRxKsCHl4esn02ZSSAlHCPzPZLxv99wXfXzlp6VFAza1Vy0JT2/L Wt138+S5W3UxXpRTA7+owK6XaBvAnSHZGkNuqj8v+ZQQ8/RPH+hOTMGuZTDqWwwssYVM mx5UQuIqmmb5Cbf8/Ne/bE11VLMvw65g4YajJvAq4NytDSWbYPoQASv7w/tSsieTjPfQ g2PHlQjquIIbXarHbYwFIxvM9rQ6X0eC7E1GT3Y6OafGhvguqHdT/tcj01G/Wu7EKjiX ChIrinG5Dt3i2OU8UpS6sID56lC72dTJdnz0V+6y/2j7PL4/T+6W4so0usK7fVpYnlhu JWjw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=/qOUfo30PmDfy59I8NSJRneNR2Umpzy9YtVUdna4m5M=; b=hIg1aSn/2eogCWRC2XLdV+e7GubORBmc3MvoOB+e3rru9K94qwM2esAT+ZyGQtDjCg qdqjl/nRrqNE81UvE77mf5ma7tHHtTlNN6NbWZVqaMU8RYFN0pRd7VKzIjB6fQvJJYjp nO3cdSy48Z/ZGNdxD3jlnzLAYeH6SLGVzZm85I7s+7SellX8DDFYLtDQmmp1jMWPajcQ OyxWTEIZ0Yg9Uy5Nsk1r4HhirE0s5RNGayy4zlWsGDhydqBZMbVVqLrxc+RLot/cEocs au5vVNnDWKh/tnkFEmBmrvG3m7bogLlKQW0SgS+BpWFld5ShyFESVXiuo0Uro5Azm2tq QJ8Q== X-Gm-Message-State: AOAM5307ogS+j8d0xFeJ5WGpV6sB9mniuNLAdtkKnpPP9N2rVMmj1Xc5 ZCIffhOmaaRrZUyxFyMZ6MsoFQ== X-Google-Smtp-Source: ABdhPJxEDfiWnL0bsJmjqgGw1L2I1bSYjlSd5sFV7BIVlK0Jo8Vgmws3GfPCG9Ng9wnj9nKM4zVG/Q== X-Received: by 2002:a2e:9a97:: with SMTP id p23mr10233046lji.375.1615813431310; Mon, 15 Mar 2021 06:03:51 -0700 (PDT) Received: from box.localdomain ([86.57.175.117]) by smtp.gmail.com with ESMTPSA id v23sm2674810lfd.259.2021.03.15.06.03.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 15 Mar 2021 06:03:49 -0700 (PDT) Received: by box.localdomain (Postfix, from userid 1000) id 7CCE710246E; Mon, 15 Mar 2021 16:03:53 +0300 (+03) Date: Mon, 15 Mar 2021 16:03:53 +0300 From: "Kirill A. Shutemov" To: David Hildenbrand Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andrew Morton , Arnd Bergmann , Michal Hocko , Oscar Salvador , Matthew Wilcox , Andrea Arcangeli , Minchan Kim , Jann Horn , Jason Gunthorpe , Dave Hansen , Hugh Dickins , Rik van Riel , "Michael S . Tsirkin" , "Kirill A . Shutemov" , Vlastimil Babka , Richard Henderson , Ivan Kokshaysky , Matt Turner , Thomas Bogendoerfer , "James E.J. Bottomley" , Helge Deller , Chris Zankel , Max Filippov , Mike Kravetz , Peter Xu , Rolf Eike Beer , linux-alpha@vger.kernel.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linux-xtensa@linux-xtensa.org, linux-arch@vger.kernel.org, Linux API Subject: Re: [PATCH RFCv2] mm/madvise: introduce MADV_POPULATE_(READ|WRITE) to prefault/prealloc memory Message-ID: <20210315130353.iqnwsnp2c2wpt4y2@box> References: <20210308164520.18323-1-david@redhat.com> <20210315122213.k52wtlbbhsw42pks@box> <7d607d1c-efd5-3888-39bb-9e5f8bc08185@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <7d607d1c-efd5-3888-39bb-9e5f8bc08185@redhat.com> Precedence: bulk List-ID: X-Mailing-List: linux-parisc@vger.kernel.org On Mon, Mar 15, 2021 at 01:25:40PM +0100, David Hildenbrand wrote: > On 15.03.21 13:22, Kirill A. Shutemov wrote: > > On Mon, Mar 08, 2021 at 05:45:20PM +0100, David Hildenbrand wrote: > > > + case -EHWPOISON: /* Skip over any poisoned pages. */ > > > + start += PAGE_SIZE; > > > + continue; > > > > Why is it good approach? It's not abvious to me. > > My main motivation was to simplify return code handling. I don't want to > return -EHWPOISON to user space Why? Hiding the problem under the rug doesn't help anybody. SIGBUS later is not better than an error upfront. -- Kirill A. Shutemov From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Kirill A. Shutemov" Subject: Re: [PATCH RFCv2] mm/madvise: introduce MADV_POPULATE_(READ|WRITE) to prefault/prealloc memory Date: Mon, 15 Mar 2021 16:03:53 +0300 Message-ID: <20210315130353.iqnwsnp2c2wpt4y2@box> References: <20210308164520.18323-1-david@redhat.com> <20210315122213.k52wtlbbhsw42pks@box> <7d607d1c-efd5-3888-39bb-9e5f8bc08185@redhat.com> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=shutemov-name.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=/qOUfo30PmDfy59I8NSJRneNR2Umpzy9YtVUdna4m5M=; b=qIqESwX8UcVPz/tRxKsCHl4esn02ZSSAlHCPzPZLxv99wXfXzlp6VFAza1Vy0JT2/L Wt138+S5W3UxXpRTA7+owK6XaBvAnSHZGkNuqj8v+ZQQ8/RPH+hOTMGuZTDqWwwssYVM mx5UQuIqmmb5Cbf8/Ne/bE11VLMvw65g4YajJvAq4NytDSWbYPoQASv7w/tSsieTjPfQ g2PHlQjquIIbXarHbYwFIxvM9rQ6X0eC7E1GT3Y6OafGhvguqHdT/tcj01G/Wu7EKjiX ChIrinG5Dt3i2OU8UpS6sID56lC72dTJdnz0V+6y/2j7PL4/T+6W4so0usK7fVpYnlhu JWjw== Content-Disposition: inline In-Reply-To: <7d607d1c-efd5-3888-39bb-9e5f8bc08185@redhat.com> List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: David Hildenbrand Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andrew Morton , Arnd Bergmann , Michal Hocko , Oscar Salvador , Matthew Wilcox , Andrea Arcangeli , Minchan Kim , Jann Horn , Jason Gunthorpe , Dave Hansen , Hugh Dickins , Rik van Riel , "Michael S . Tsirkin" , "Kirill A . Shutemov" , Vlastimil Babka , Richard Henderson , Ivan Kokshaysky , Matt Turner , Thomas Bogendoerfer On Mon, Mar 15, 2021 at 01:25:40PM +0100, David Hildenbrand wrote: > On 15.03.21 13:22, Kirill A. Shutemov wrote: > > On Mon, Mar 08, 2021 at 05:45:20PM +0100, David Hildenbrand wrote: > > > + case -EHWPOISON: /* Skip over any poisoned pages. */ > > > + start += PAGE_SIZE; > > > + continue; > > > > Why is it good approach? It's not abvious to me. > > My main motivation was to simplify return code handling. I don't want to > return -EHWPOISON to user space Why? Hiding the problem under the rug doesn't help anybody. SIGBUS later is not better than an error upfront. -- Kirill A. Shutemov