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=-5.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 4E2CCC433DF for ; Tue, 18 Aug 2020 09:29:56 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id ECFCC20639 for ; Tue, 18 Aug 2020 09:29:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=samsung.com header.i=@samsung.com header.b="QyxYZvG9" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ECFCC20639 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=samsung.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 905626B002F; Tue, 18 Aug 2020 05:29:55 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8B5E76B0030; Tue, 18 Aug 2020 05:29:55 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 77F238D0003; Tue, 18 Aug 2020 05:29:55 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0063.hostedemail.com [216.40.44.63]) by kanga.kvack.org (Postfix) with ESMTP id 618AE6B002F for ; Tue, 18 Aug 2020 05:29:55 -0400 (EDT) Received: from smtpin09.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 0BCEB180AD838 for ; Tue, 18 Aug 2020 09:29:55 +0000 (UTC) X-FDA: 77163167550.09.room16_1213c2a2701e Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin09.hostedemail.com (Postfix) with ESMTP id D5A9B180AD82F for ; Tue, 18 Aug 2020 09:29:54 +0000 (UTC) X-HE-Tag: room16_1213c2a2701e X-Filterd-Recvd-Size: 8815 Received: from mailout3.samsung.com (mailout3.samsung.com [203.254.224.33]) by imf48.hostedemail.com (Postfix) with ESMTP for ; Tue, 18 Aug 2020 09:29:53 +0000 (UTC) Received: from epcas2p1.samsung.com (unknown [182.195.41.53]) by mailout3.samsung.com (KnoxPortal) with ESMTP id 20200818092950epoutp03b0d7adae7defb16beb711f5968f6b3e1~sUsjqjtlH0095100951epoutp03l for ; Tue, 18 Aug 2020 09:29:50 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 mailout3.samsung.com 20200818092950epoutp03b0d7adae7defb16beb711f5968f6b3e1~sUsjqjtlH0095100951epoutp03l DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=samsung.com; s=mail20170921; t=1597742990; bh=qdTzzaTlwqHvBMvbIXgF5S6rKlk6fyMkr6hYFJXqtio=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=QyxYZvG9us5o+WMYyHR5G43COwKJtI1os++/XgSkOQ/KzNUS0DMlcz8H01+LgPqlW KyaONuZcPeHRE935ItWqJcAwBbDzIklcn1o4xX4LFZeDq/H1vzF5VseLx9LzU+gtJ0 6NRRWHKbMUKj+B8+un6wWppSfW4XkaIZ9Ou5x+IU= Received: from epsnrtp3.localdomain (unknown [182.195.42.164]) by epcas2p1.samsung.com (KnoxPortal) with ESMTP id 20200818092949epcas2p11e1b66bfb66def3ad550ff19c99c0b5f~sUsjAoJkK2596125961epcas2p1U; Tue, 18 Aug 2020 09:29:49 +0000 (GMT) Received: from epsmges2p2.samsung.com (unknown [182.195.40.186]) by epsnrtp3.localdomain (Postfix) with ESMTP id 4BW5Gg56JHzMqYkh; Tue, 18 Aug 2020 09:29:47 +0000 (GMT) Received: from epcas2p4.samsung.com ( [182.195.41.56]) by epsmges2p2.samsung.com (Symantec Messaging Gateway) with SMTP id 00.88.18874.B8F9B3F5; Tue, 18 Aug 2020 18:29:47 +0900 (KST) Received: from epsmtrp1.samsung.com (unknown [182.195.40.13]) by epcas2p3.samsung.com (KnoxPortal) with ESMTPA id 20200818092947epcas2p363a961385151345686f7fd8824d32f93~sUsgVCWDV2125821258epcas2p3v; Tue, 18 Aug 2020 09:29:47 +0000 (GMT) Received: from epsmgms1p1new.samsung.com (unknown [182.195.42.41]) by epsmtrp1.samsung.com (KnoxPortal) with ESMTP id 20200818092947epsmtrp1afa11c9c5e74fa3c3da4a0d4e7dee4bd~sUsgUU_wy1606416064epsmtrp1x; Tue, 18 Aug 2020 09:29:47 +0000 (GMT) X-AuditID: b6c32a46-503ff700000049ba-22-5f3b9f8bc354 Received: from epsmtip2.samsung.com ( [182.195.34.31]) by epsmgms1p1new.samsung.com (Symantec Messaging Gateway) with SMTP id D7.1A.08382.A8F9B3F5; Tue, 18 Aug 2020 18:29:46 +0900 (KST) Received: from KEI (unknown [12.36.155.227]) by epsmtip2.samsung.com (KnoxPortal) with ESMTPA id 20200818092946epsmtip2c133b94e0339ad2350a851cb09acf1bd~sUsgH_Fse1630716307epsmtip2P; Tue, 18 Aug 2020 09:29:46 +0000 (GMT) Date: Tue, 18 Aug 2020 18:22:15 +0900 From: Cho KyongHo To: Minchan Kim Cc: Matthew Wilcox , Andrew Morton , linux-mm , Joonsoo Kim , Vlastimil Babka , John Dias , Suren Baghdasaryan , hyesoo.yu@samsung.com, janghyuck.kim@samsung.com Subject: Re: [RFC 0/7] Support high-order page bulk allocation Message-ID: <20200818092215.GA191752@KEI> MIME-Version: 1.0 In-Reply-To: <20200814205558.GA2814941@google.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFtrCJsWRmVeSWpSXmKPExsWy7bCmhW73fOt4gwNrNSzmrF/DZvG38wKr xcruZjaLzXOKLb4veMRscW/Nf1aLZV/fs1tMvrSAzWJ2Yx+jxe8fc9gcuDwWbCr12LxCy2PT qk42j02fJrF7dL29wuRxYsZvFo++LasYPc4sOMIewBGVY5ORmpiSWqSQmpecn5KZl26r5B0c 7xxvamZgqGtoaWGupJCXmJtqq+TiE6DrlpkDdKKSQlliTilQKCCxuFhJ386mKL+0JFUhI7+4 xFYptSAlp8DQsECvODG3uDQvXS85P9fK0MDAyBSoMiEnY/XaiewF14UrZr/9yd7AuIm/i5GT Q0LAROLKpKNMXYxcHEICOxgltq58xwbhfGKU+HW8gxXC+cYo0X/7PytMy9tXH6Gq9jJKfP/f xgySEBJ4yCjxpcsPxGYRUJXY0n+YHcRmE9CSWD33OCOILSKgIvHn6T9GkGZmgb1MEtf/vgRa zsEhLGAnsXenIkgNr4CmxLz+o6wQtqDEyZlPWEBsTgEjialrH7OClIsCzXl1sB5kjITAUg6J h1Nms0Ac5yLxY/5BRghbWOLV8S3sELaUxMv+NnaIhumMEu/mH2KDSGxmlPi2WxDCNpaY9awd rJlZIENi2qWrjCDLJASUJY7cYoEI80l0HP7LDhHmlehoE4LoVJHYOfUaC8yqvr03oGwPicnH etghYfWUUeLiym7GCYzys5C8NgvJNghbR2LB7k9ss4BWMAtISyz/xwFhakqs36W/gJF1FaNY akFxbnpqsVGBEXJkb2IEJ18ttx2MU95+0DvEyMTBeIhRgoNZSYQ36YR5vBBvSmJlVWpRfnxR aU5q8SFGU2A8TWSWEk3OB6b/vJJ4Q1MjMzMDS1MLUzMjCyVx3nrFC3FCAumJJanZqakFqUUw fUwcnFINTDbO+r2b9P7x1Ogy8VmqBOfdu7X0le9kg6cqc7/EnptRoSbZ/bz20QebV+vO6Z7+ y3Nc7PWC24uCTpsd+yqiIf6O0+aMwLeypVsvrdF/K3V0WaHRQRbvzJiY/4wnzK0VJtf+m2Sa 5dTufev+p02WNSstDn26qKajWO1R+/ml3aM0Uz2pxDOmKp/P2vW6Xm0+evWC5+lTlk8XJR5e 8P6Fk9aTTm1711ZX90MlEWH/eXs2KnALMrD4TRAzEmi3cmI7lvpAvUwtkSnx7Sf2X/Yy5et+ Bsqn7Tphekbse3d3YILN+a8TnN8E2Wek8kxgTe56I9N16Etg0YTUUgW/sqMLbT63TOFKvrNq p8RNsyJtJZbijERDLeai4kQAcvrmnEcEAAA= X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFvrOLMWRmVeSWpSXmKPExsWy7bCSvG73fOt4g0myFnPWr2Gz+Nt5gdVi ZXczm8XmOcUW3xc8Yra4t+Y/q8Wyr+/ZLSZfWsBmMbuxj9Hi9485bA5cHgs2lXpsXqHlsWlV J5vHpk+T2D263l5h8jgx4zeLR9+WVYweZxYcYQ/giOKySUnNySxLLdK3S+DKuPL2P1vBdMGK b53/2BsYu3m7GDk5JARMJN6++sjWxcjFISSwm1FiU99SJoiElMS87rVQtrDE/ZYjrBBF9xkl OrobWUASLAKqElv6D7OD2GwCWhKr5x5nBLFFBFQk/jz9xwjSwCywn0li/6nbQN0cHMICdhJ7 dyqC1PAKaErM6z/KCmILCTxllJi0MR8iLihxcuYTsPnMQDNv/HvJBNLKLCAtsfwfB0iYU8BI Yurax2ATRYFWvTpYP4FRcBaS5llImmchNC9gZF7FKJlaUJybnltsWGCYl1quV5yYW1yal66X nJ+7iREcN1qaOxi3r/qgd4iRiYPxEKMEB7OSCG/SCfN4Id6UxMqq1KL8+KLSnNTiQ4zSHCxK 4rw3ChfGCQmkJ5akZqemFqQWwWSZODilGph28nj7+l+Xjzn+96Te57wvD3L/X9OZ+nv37Y3K 8418G60j2KJnXmZ/LDypUD7r09SfmwPm7+QSTKsVsPLUfLNIQmjJ/Wl7rcx+c9joCgadmBIQ t50zxqmG785Pq+jdu+ZF/0vU8XsyJ/rk3TsLuG4cLfsWup+7YU/y0fjnfdwhWWm+0j1L0pq1 4zSml+v+j/JgW8u0+//deolrkm1TDQ44CrC/78zbKnJPeuKznf0Ls8zZ/wYLJznOFL+43ew/ 222/iXHGiYdLynYeSPylF/RY4XE5z0uuooR/Z3o/3PG8bqjOvOHB89Vnc2r9JmUrrVv6lkE/ 88Xs+EwJng/cjxrjG+5O6To7+f4Kf/3yR9eVWIozEg21mIuKEwGgfPSzCgMAAA== X-CMS-MailID: 20200818092947epcas2p363a961385151345686f7fd8824d32f93 X-Msg-Generator: CA Content-Type: multipart/mixed; boundary="----gThi6U1shImpkjjsILNGKqES4Uk8qk2Gal-jc_NwJ8V0sbs9=_29d83_" X-Sendblock-Type: AUTO_CONFIDENTIAL CMS-TYPE: 102P DLP-Filter: Pass X-CFilter-Loop: Reflected X-CMS-RootMailID: 20200814205604epcas2p33600c4c687dfd1ec211807c95cdcf762 References: <20200814173131.2803002-1-minchan@kernel.org> <20200814174020.GX17456@casper.infradead.org> <20200814205558.GA2814941@google.com> X-Rspamd-Queue-Id: D5A9B180AD82F X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam05 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: ------gThi6U1shImpkjjsILNGKqES4Uk8qk2Gal-jc_NwJ8V0sbs9=_29d83_ Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline On Fri, Aug 14, 2020 at 01:55:58PM -0700, Minchan Kim wrote: > On Fri, Aug 14, 2020 at 06:40:20PM +0100, Matthew Wilcox wrote: > > On Fri, Aug 14, 2020 at 10:31:24AM -0700, Minchan Kim wrote: > > > There is a need for special HW to require bulk allocation of > > > high-order pages. For example, 4800 * order-4 pages. > > > > ... but you haven't shown that user. > > Kyoungho is working on it. > I am not sure how much he could share but hopefully, he could > show some. Kyoungho? > Hyesoo posted a patch series that uses alloc_pages_bulk() in a dma-heap; please take a look at: https://lore.kernel.org/linux-mm/20200818080415.7531-1-hyesoo.yu@samsung.com/ The patch series introduces a new type of dma-heap, chunk heap which is initialized by a device tree node. The chunk heap also needs its device tree node should have a phandle to reserved memory node with "reusable" property. > > > > > int alloc_pages_bulk(unsigned long start, unsigned long end, > > > unsigned int migratetype, gfp_t gfp_mask, > > > unsigned int order, unsigned int nr_elem, > > > struct page **pages); > > > > > > It will investigate the [start, end) and migrate movable pages > > > out there by best effort(by upcoming patches) to make requested > > > order's free pages. > > > > > > The allocated pages will be returned using pages parameter. > > > Return value represents how many of requested order pages we got. > > > It could be less than user requested by nr_elem. > > > > I don't understand why a user would need to know the PFNs to allocate > > between. This seems like something that's usually specified by GFP_DMA32 > > or similar. > > I wanted to let the API wok from CMA area and/or movable zone where are > always fulled with migrable pages. > If we carry on only zone flags without pfn range, it couldn't fulfil cma > area cases. > Other reason is if user see fewer pages returned, he could try subsequent > ranges to get remained ones. > > > Is it useful to return fewer pages than requested? > > It's useful because user could ask further than what they need or retry. > ------gThi6U1shImpkjjsILNGKqES4Uk8qk2Gal-jc_NwJ8V0sbs9=_29d83_ Content-Type: text/plain; charset="utf-8" ------gThi6U1shImpkjjsILNGKqES4Uk8qk2Gal-jc_NwJ8V0sbs9=_29d83_--