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=-2.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 B99C1C49ED9 for ; Thu, 12 Sep 2019 10:24:45 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 8E39E208C2 for ; Thu, 12 Sep 2019 10:24:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="SEWKJLVs"; dkim=fail reason="signature verification failed" (2048-bit key) header.d=shutemov-name.20150623.gappssmtp.com header.i=@shutemov-name.20150623.gappssmtp.com header.b="rjY82Sy3" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8E39E208C2 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=shutemov.name Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=GlipExXvH9UFfX5Mhnxv135ziANDMLrwE0y5/KdVZMo=; b=SEWKJLVsBtIt3r +KCgnabsWFZp8CHWpdpxm58i9DIrq+3q2Yi/BmD6kQKYpSnojxbGqxEcbkZdExF027F3RTUC3akLj UayT8wOvjrhSg9BJIRrhZ/TL49Li/pFm6c9jA3DKtZYYvSR9LDJlGnwgr3xzH4o3yq/PUSOvxB8pm ALxf9xaN0wwiJ7rysKATQqPnu2BtFoWxGszqI0+spKZdJtvbLJC98nr2OIY/qUtgNWGqiBF1aJrqP ky2LONft9nGBqAponZ9vQE+hmP5ySPiWuP8jo0e9RSha/c5sds2g79QS2YvaOlPiV/DbfnMdplBUW JpJKoWKr44CsYTBz3Puw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.2 #3 (Red Hat Linux)) id 1i8MH8-0000XD-W6; Thu, 12 Sep 2019 10:24:31 +0000 Received: from mail-ed1-x541.google.com ([2a00:1450:4864:20::541]) by bombadil.infradead.org with esmtps (Exim 4.92.2 #3 (Red Hat Linux)) id 1i8MH5-0000Wq-FJ for linux-arm-kernel@lists.infradead.org; Thu, 12 Sep 2019 10:24:28 +0000 Received: by mail-ed1-x541.google.com with SMTP id c20so14450888eds.1 for ; Thu, 12 Sep 2019 03:24:26 -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:user-agent; bh=+mmfaBX0Np9W/b7Q5MqD32lbNina1cQ/FOr9Xbx+2SA=; b=rjY82Sy3etyc/lURHAAH5Zl+/VTkVL1QfiSGIjGFzaoW/tFRFM+zEYupBdTECALHrG yPnD/zet+9v/0zbzm/E5VjxIC4kHBGoI6fG6y3ZudVWE1Fqr5jUEFHOhmpHGUgJBjFLR Pp4qZYYyCBsVXmvAX8dVxq7xFDjWJd+exfdSoleHOrbAKfryXx1FyZtARD7dR7tAJFzo JrefYLyjWx+Ptmb0NQyHMPY02QIUK5RaU1NoX/BBPIIVc7yZpU9xVdpA7vqiSPpdXXbt d5OJ8VA03djK7lmxCv6oPg+S+/UFNoBoSlbJXwZ5azlQ2uo9F1xXDa4+5x33RZHpoQkO TV/w== 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:user-agent; bh=+mmfaBX0Np9W/b7Q5MqD32lbNina1cQ/FOr9Xbx+2SA=; b=lpIMbmO8EXYlMYBTQqICJJqbnFr5Ui0lXV3BtuzeXBqgS35ZFeHaH/x8lxhukQFY4q KD0jgsO2Whqc9LE9tm0vsqFii7/lffnayRyI2VcwFWL7JIdrSBB4sHrUa/YoIjjJg4UA 33GfpkY2k5uk2bOgVZauhV74jVAtdDaSLOsC25nv1IHoH1m6XPDIubDqgLhbVGBwYLoR fRE7SswK0UoDlnSzw/8k3IblIsgUodDT71AOM9UDn2zOjALIQYI+8nW/qfi7Zq9FdvhN fI3BnQc/e0xTFDIS1heI+D/1BOb5OZsXdKzwc3qlzdjk1b/KVZ+0vjxF6/QsJpzNFxWV GrHw== X-Gm-Message-State: APjAAAUJ14QGVTfHUxOqQ2BhbMUgIy8+rM6qRGLsHOjP/s1ilDJ1rdIF KQOdp5BEjRzfkoptVNoN/t3BiQ== X-Google-Smtp-Source: APXvYqxqQuNiTjkjaC8Hs02PHF+LHAOwtw4KJLDqhBlQ3F6XmLygJAqZUw/cEZVOIq4hY2vxi9be2Q== X-Received: by 2002:a50:8961:: with SMTP id f30mr40528236edf.144.1568283865271; Thu, 12 Sep 2019 03:24:25 -0700 (PDT) Received: from box.localdomain ([86.57.175.117]) by smtp.gmail.com with ESMTPSA id qt5sm2710889ejb.11.2019.09.12.03.24.24 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 12 Sep 2019 03:24:24 -0700 (PDT) Received: by box.localdomain (Postfix, from userid 1000) id 04633100B4A; Thu, 12 Sep 2019 13:24:26 +0300 (+03) Date: Thu, 12 Sep 2019 13:24:25 +0300 From: "Kirill A. Shutemov" To: Michal Hocko Subject: Re: [PATCH v9 0/8] stg mail -e --version=v9 \ Message-ID: <20190912102425.wzhhe6ygfgg64sma@box> References: <20190907172225.10910.34302.stgit@localhost.localdomain> <20190910124209.GY2063@dhcp22.suse.cz> <20190910144713.GF2063@dhcp22.suse.cz> <20190910175213.GD4023@dhcp22.suse.cz> <1d7de9f9f4074f67c567dbb4cc1497503d739e30.camel@linux.intel.com> <20190911113619.GP4023@dhcp22.suse.cz> <20190912091925.GM4023@dhcp22.suse.cz> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190912091925.GM4023@dhcp22.suse.cz> User-Agent: NeoMutt/20180716 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190912_032427_546938_2FDE9120 X-CRM114-Status: GOOD ( 21.58 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Yang Zhang , Pankaj Gupta , kvm list , "Michael S. Tsirkin" , Catalin Marinas , Alexander Duyck , lcapitulino@redhat.com, linux-mm , Alexander Duyck , will@kernel.org, Andrea Arcangeli , virtio-dev@lists.oasis-open.org, David Hildenbrand , Matthew Wilcox , "Wang, Wei W" , Mel Gorman , ying.huang@intel.com, Rik van Riel , Vlastimil Babka , Dan Williams , linux-arm-kernel@lists.infradead.org, Oscar Salvador , Nitesh Narayan Lal , Konrad Rzeszutek Wilk , Dave Hansen , LKML , Paolo Bonzini , Andrew Morton , Fengguang Wu , "Kirill A. Shutemov" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Sep 12, 2019 at 11:19:25AM +0200, Michal Hocko wrote: > On Wed 11-09-19 08:12:03, Alexander Duyck wrote: > > On Wed, Sep 11, 2019 at 4:36 AM Michal Hocko wrote: > > > > > > On Tue 10-09-19 14:23:40, Alexander Duyck wrote: > > > [...] > > > > We don't put any limitations on the allocator other then that it needs to > > > > clean up the metadata on allocation, and that it cannot allocate a page > > > > that is in the process of being reported since we pulled it from the > > > > free_list. If the page is a "Reported" page then it decrements the > > > > reported_pages count for the free_area and makes sure the page doesn't > > > > exist in the "Boundary" array pointer value, if it does it moves the > > > > "Boundary" since it is pulling the page. > > > > > > This is still a non-trivial limitation on the page allocation from an > > > external code IMHO. I cannot give any explicit reason why an ordering on > > > the free list might matter (well except for page shuffling which uses it > > > to make physical memory pattern allocation more random) but the > > > architecture seems hacky and dubious to be honest. It shoulds like the > > > whole interface has been developed around a very particular and single > > > purpose optimization. > > > > How is this any different then the code that moves a page that will > > likely be merged to the tail though? > > I guess you are referring to the page shuffling. If that is the case > then this is an integral part of the allocator for a reason and it is > very well obvious in the code including the consequences. I do not > really like an idea of hiding similar constrains behind a generic > looking feature which is completely detached from the allocator and so > any future change of the allocator might subtly break it. I don't necessary follow why shuffling is more integral to page allocator than reporting would be. It's next to shutffle.c under mm/ and integrated in a simillar way. -- Kirill A. Shutemov _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel