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 5CDFAC433F5 for ; Fri, 10 Dec 2021 07:30:36 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 579DE6B0071; Fri, 10 Dec 2021 02:30:25 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 528F36B0072; Fri, 10 Dec 2021 02:30:25 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 417BC6B0074; Fri, 10 Dec 2021 02:30:25 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay040.a.hostedemail.com [64.99.140.40]) by kanga.kvack.org (Postfix) with ESMTP id 32A4D6B0071 for ; Fri, 10 Dec 2021 02:30:25 -0500 (EST) Received: from smtpin02.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id EC8EF9D5 for ; Fri, 10 Dec 2021 07:30:14 +0000 (UTC) X-FDA: 78901061148.02.1FBB4EF Received: from mail-pl1-f170.google.com (mail-pl1-f170.google.com [209.85.214.170]) by imf18.hostedemail.com (Postfix) with ESMTP id 523451C0007 for ; Fri, 10 Dec 2021 07:30:13 +0000 (UTC) Received: by mail-pl1-f170.google.com with SMTP id n8so5710905plf.4 for ; Thu, 09 Dec 2021 23:30:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=message-id:date:mime-version:user-agent:subject:to:cc:references :from:in-reply-to:content-transfer-encoding; bh=kqdwZyEU31KaNW+cOFp1dor6RRAOvhH6zrtcJuFenfA=; b=gqnhaZdO12ibnFTEUYTRcyNDsVi4fZjKWuF1d+1IX2QtK+zXEl/CleEzgCXcZCKWk4 DeGXeYahXgF25toJDTBvItitvosjjzyrdtCOfzBPXJUv2sNA46FGCrVbWvzev5Gqa7Ak meZ3c5sCNkdjOENTF0nlgXWFhqmZAwIOkT71xtM4OT2BCJb5l3qSGmgij0kaSHc39jlT lz+NQj74lZEDNXhnwDnJm6MBPftfgIEvxzLs37o6722DhjM05TgsyYdxT05vxKbTRo5c paO1XE+hWA5qYswHrUze+qL1vRsNsy/KmrR7y+w/OwTPs4iJXL+3vAPXn7Z6f5NDhlEr bj6A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :to:cc:references:from:in-reply-to:content-transfer-encoding; bh=kqdwZyEU31KaNW+cOFp1dor6RRAOvhH6zrtcJuFenfA=; b=6sqbZsJucif3LI0N+uu27/Maictac4LP1dkHUbkD4vCScu+/7/1Uak7JMUjVWbD2V/ 8+hW9K2tGVT14DK97s1y92+kQ9zjplq2UImX8MnO4Ug47N9Z1EFYFN3BOjBpzw3/I53T 6ubjxzP5ecJ8Tv61XqgQtZRHrTFpbsEvjhMJyl75glLTu5PTsiNuDEgM/Fm479oulhUI mDIxqD9JsZmMM/H1UT/M+qm+Uh/LxZU7qVoLvR+1084h7+6xZtT41T0E7BHNR8japF+o QBfkX6QkcVrcSsA1Uo767zDUgX3E0p+yIbgpYig4HG0L8phYBr9gKn93PgsUala+1dlq gNFg== X-Gm-Message-State: AOAM531MwQ6LVEXeswCqzZ8qU5EX0MBY0OltXG8iQyVlfeNuauoz7vz+ 9dlmWBE4o4aj1EmEzBng67g= X-Google-Smtp-Source: ABdhPJxRm9ttF7FhbBeprnb6+zsZD1lD+fI51oOUlTadE/AU/yNXP9DA3iOR8FWZWbadxSA9RFDXLw== X-Received: by 2002:a17:902:f687:b0:141:cf6b:fee7 with SMTP id l7-20020a170902f68700b00141cf6bfee7mr71919578plg.75.1639121413466; Thu, 09 Dec 2021 23:30:13 -0800 (PST) Received: from [30.240.98.4] ([205.204.117.108]) by smtp.gmail.com with ESMTPSA id c17sm185764pfc.163.2021.12.09.23.30.09 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 09 Dec 2021 23:30:13 -0800 (PST) Message-ID: <07f11dfc-f491-3b08-a2cb-3c8f5a8102d3@gmail.com> Date: Fri, 10 Dec 2021 15:30:02 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0) Gecko/20100101 Thunderbird/91.2.1 Subject: Re: [RFC PATCH v2 0/7] Use pageblock_order for cma and alloc_contig_range alignment. To: Zi Yan , David Hildenbrand , linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, Michael Ellerman , Christoph Hellwig , Marek Szyprowski , Robin Murphy , linuxppc-dev@lists.ozlabs.org, virtualization@lists.linux-foundation.org, iommu@lists.linux-foundation.org, Vlastimil Babka , Mel Gorman References: <20211209230414.2766515-1-zi.yan@sent.com> From: Eric Ren In-Reply-To: <20211209230414.2766515-1-zi.yan@sent.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: 523451C0007 X-Stat-Signature: n65u9kf7euq3b977bgriitakopes4ncm Authentication-Results: imf18.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=gqnhaZdO; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf18.hostedemail.com: domain of renzhengeek@gmail.com designates 209.85.214.170 as permitted sender) smtp.mailfrom=renzhengeek@gmail.com X-HE-Tag: 1639121413-50820 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: Hi Zi Yan, On 2021/12/10 07:04, Zi Yan wrote: > From: Zi Yan > > Hi all, > > This patchset tries to remove the MAX_ORDER - 1 alignment requirement for CMA > and alloc_contig_range(). It prepares for my upcoming changes to make MAX_ORDER > adjustable at boot time[1]. > > The MAX_ORDER - 1 alignment requirement comes from that alloc_contig_range() > isolates pageblocks to remove free memory from buddy allocator but isolating > only a subset of pageblocks within a page spanning across multiple pageblocks > causes free page accounting issues. Isolated page might not be put into the > right free list, since the code assumes the migratetype of the first pageblock > as the whole free page migratetype. This is based on the discussion at [2]. > > To remove the requirement, this patchset: > 1. still isolates pageblocks at MAX_ORDER - 1 granularity; Then, unplug fails if either pageblock of the  MAX_ORDER - 1 page has unmovable page, right? Thanks, Eric > 2. but saves the pageblock migratetypes outside the specified range of > alloc_contig_range() and restores them after all pages within the range > become free after __alloc_contig_migrate_range(); > 3. splits free pages spanning multiple pageblocks at the beginning and the end > of the range and puts the split pages to the right migratetype free lists > based on the pageblock migratetypes; > 4. returns pages not in the range as it did before this patch. > > Isolation needs to happen at MAX_ORDER - 1 granularity, because otherwise > 1) extra code is needed to detect pages (free, PageHuge, THP, or PageCompound) > to make sure all pageblocks belonging to a single page are isolated together > and later pageblocks outside the range need to have their migratetypes restored; > or 2) extra logic will need to be added during page free time to split a free > page with multi-migratetype pageblocks. > > Two optimizations might come later: > 1. only check unmovable pages within the range instead of MAX_ORDER - 1 aligned > range during isolation to increase successful rate of alloc_contig_range(). > 2. make MIGRATE_ISOLATE a separate bit to avoid saving and restoring existing > migratetypes before and after isolation respectively. > > Feel free to give comments and suggestions. Thanks. > > > [1] https://lore.kernel.org/linux-mm/20210805190253.2795604-1-zi.yan@sent.com/ > [2] https://lore.kernel.org/linux-mm/d19fb078-cb9b-f60f-e310-fdeea1b947d2@redhat.com/ > > > Zi Yan (7): > mm: page_alloc: avoid merging non-fallbackable pageblocks with others. > mm: compaction: handle non-lru compound pages properly in > isolate_migratepages_block(). > mm: migrate: allocate the right size of non hugetlb or THP compound > pages. > mm: make alloc_contig_range work at pageblock granularity > mm: cma: use pageblock_order as the single alignment > drivers: virtio_mem: use pageblock size as the minimum virtio_mem > size. > arch: powerpc: adjust fadump alignment to be pageblock aligned. > > arch/powerpc/include/asm/fadump-internal.h | 4 +- > drivers/virtio/virtio_mem.c | 6 +- > include/linux/mmzone.h | 11 +- > kernel/dma/contiguous.c | 2 +- > mm/cma.c | 6 +- > mm/compaction.c | 10 +- > mm/migrate.c | 8 +- > mm/page_alloc.c | 203 +++++++++++++++++---- > 8 files changed, 196 insertions(+), 54 deletions(-) >