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[209.132.180.67]) by mx.google.com with ESMTP id bb11si19496626plb.420.2019.03.27.10.02.17; Wed, 27 Mar 2019 10:02:37 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@nvidia.com header.s=n1 header.b=IvZHSl+t; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=nvidia.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727913AbfC0RBJ (ORCPT + 99 others); Wed, 27 Mar 2019 13:01:09 -0400 Received: from hqemgate16.nvidia.com ([216.228.121.65]:17863 "EHLO hqemgate16.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727172AbfC0RBJ (ORCPT ); Wed, 27 Mar 2019 13:01:09 -0400 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqemgate16.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Wed, 27 Mar 2019 10:00:50 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Wed, 27 Mar 2019 10:00:52 -0700 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Wed, 27 Mar 2019 10:00:52 -0700 Received: from [10.2.164.169] (10.124.1.5) by HQMAIL101.nvidia.com (172.20.187.10) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Wed, 27 Mar 2019 17:00:52 +0000 From: Zi Yan To: Keith Busch CC: Yang Shi , , , , , , "Hansen, Dave" , "Busch, Keith" , "Williams, Dan J" , "Wu, Fengguang" , "Du, Fan" , "Huang, Ying" , , Subject: Re: [PATCH 06/10] mm: vmscan: demote anon DRAM pages to PMEM node Date: Wed, 27 Mar 2019 10:00:51 -0700 X-Mailer: MailMate (1.12.4r5622) Message-ID: <2C32F713-2156-4B58-B5C1-789C1821EBB9@nvidia.com> In-Reply-To: <20190327130822.GD7389@localhost.localdomain> References: <1553316275-21985-1-git-send-email-yang.shi@linux.alibaba.com> <1553316275-21985-7-git-send-email-yang.shi@linux.alibaba.com> <20190324222040.GE31194@localhost.localdomain> <20190327003541.GE4328@localhost.localdomain> <39d8fb56-df60-9382-9b47-59081d823c3c@linux.alibaba.com> <20190327130822.GD7389@localhost.localdomain> MIME-Version: 1.0 X-Originating-IP: [10.124.1.5] X-ClientProxiedBy: HQMAIL101.nvidia.com (172.20.187.10) To HQMAIL101.nvidia.com (172.20.187.10) Content-Type: multipart/signed; boundary="=_MailMate_FDAFDC66-07F4-44F7-9872-93BE2994CEDA_="; micalg=pgp-sha1; protocol="application/pgp-signature" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1553706051; bh=Io+E5uEESZPp1e9HALilVFuhRQtmhI/36F2P/dMd/ho=; h=X-PGP-Universal:From:To:CC:Subject:Date:X-Mailer:Message-ID: In-Reply-To:References:MIME-Version:X-Originating-IP: X-ClientProxiedBy:Content-Type; b=IvZHSl+tgFV6D4idQxZTXdUfHMcBl+ShUvrE5uXkfGG4Db3DX2DHDQh17O39LV+ce Ufm4OpM6vpWU7wTDnsIDvtuihTe+yCyZWkJMVuXSaQii6g+GCdajD7ejGKrXwOWFvH R2Tun0CTNZO/Vkemb6HWBLBraOi3aIdjCFOLV4Cndo0UtQ8Nk7AxveDhV+p9tD2iqm /atJ0ZPWGg+7QVN+2YnXt/yrnwtHVUneUR+WzjMOoeyKie6OewIkspWPJkeuUCLiCo EDAoZJpQJlva3Fb6BtW0Obq1cnGuDCzePtOcgsTLGk6KA/RQvAzf2JCfjvBdh5q4fr 7dbfuZb7tL7zg== Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --=_MailMate_FDAFDC66-07F4-44F7-9872-93BE2994CEDA_= Content-Type: text/plain; markup=markdown On 27 Mar 2019, at 6:08, Keith Busch wrote: > On Tue, Mar 26, 2019 at 08:41:15PM -0700, Yang Shi wrote: >> On 3/26/19 5:35 PM, Keith Busch wrote: >>> migration nodes have higher free capacity than source nodes. And since >>> your attempting THP's without ever splitting them, that also requires >>> lower fragmentation for a successful migration. >> >> Yes, it is possible. However, migrate_pages() already has logic to >> handle such case. If the target node has not enough space for migrating >> THP in a whole, it would split THP then retry with base pages. > > Oh, you're right, my mistake on splitting. So you have a good best effort > migrate, but I still think it can fail for legitimate reasons that should > have a swap fallback. Does this mean we might want to factor out the page reclaim code in shrink_page_list() and call it for each page, which fails to migrate to PMEM. Or do you still prefer to migrate one page at a time, like what you did in your patch? I ask this because I observe that migrating a list of pages can achieve higher throughput compared to migrating individual page. For example, migrating 512 4KB pages can achieve ~750MB/s throughput, whereas migrating one 4KB page might only achieve ~40MB/s throughput. The experiments were done on a two-socket machine with two Xeon E5-2650 v3 @ 2.30GHz across the QPI link. -- Best Regards, Yan Zi --=_MailMate_FDAFDC66-07F4-44F7-9872-93BE2994CEDA_= Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQJDBAEBAgAtFiEEh7yFAW3gwjwQ4C9anbJR82th+ooFAlybrEMPHHppeUBudmlk aWEuY29tAAoJEJ2yUfNrYfqK/twP/3lcO6kKxaHl/38KpTngJX//h7UJzoANsSrb le5gVdUnBGP9KnFWyltBDEbNggucShHm+U5hFBvrkDzY/fO8BJTM5ypXiPxDr7h1 5XyvCJuuBtSE24X5autv1xF4QKIHTb69N9uojoMy4WYyQmnuuuMTC6vFICUinQuL pQHHtx2VxINXRVPOcW6XMYxBopW5+MuYyXtFRrT9+tEQvJ9Fw3Gwg0JwuiEZx9Sh aUJhOrg+43Lfs0ES0i31Mw7KD+csr/uii+HVdOT/FBEtge8QvxlV2FxBnINkpHa6 xVo5cWoNbo++rdpobmnOsjQvJ01WWyoaTwvHOITU5zmH85IVraI0N7G5PsCMuexB Hvvndlo+WNcGTvF3YgQgLb/0xRjqT77Jwli7rXMNhihXLyw5cZrGTwueEJV8saou oXDw7WzLUokCPPuhdicKt8uQ+encxv20TxGxZrPCu9hL+7+s/DLZ3BhwptTkvhbF TQeGbfbCKTlifJ3AqSi1041vwxTz2C0moUz5kWIgf2rZG/NlM8S6AwPv2hHTxzLZ PEtY7fdJCEYLk5DPkkwBxpiH/JM/yyQLH0WOHYpbxWxtR/5CMnE+YR1JNL2hKs7e kOalkTxRURDb/3+uGUAPWEY+VWOhzU5DIsO28zXopEQCWB+sVYinCLhUdgroRgAD Bx5LaaKT =HFOS -----END PGP SIGNATURE----- --=_MailMate_FDAFDC66-07F4-44F7-9872-93BE2994CEDA_=--