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=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable 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 49EEDC6379D for ; Fri, 27 Nov 2020 15:17:41 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id D1EA1206CA for ; Fri, 27 Nov 2020 15:17:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D1EA1206CA Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.cz Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 65F446B006C; Fri, 27 Nov 2020 10:17:40 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 60F106B006E; Fri, 27 Nov 2020 10:17:40 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 526746B0070; Fri, 27 Nov 2020 10:17:40 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0140.hostedemail.com [216.40.44.140]) by kanga.kvack.org (Postfix) with ESMTP id 3E28D6B006C for ; Fri, 27 Nov 2020 10:17:40 -0500 (EST) Received: from smtpin17.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id F2DA2180AD820 for ; Fri, 27 Nov 2020 15:17:39 +0000 (UTC) X-FDA: 77530552680.17.frame05_421704727389 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin17.hostedemail.com (Postfix) with ESMTP id D726E180D0184 for ; Fri, 27 Nov 2020 15:17:39 +0000 (UTC) X-HE-Tag: frame05_421704727389 X-Filterd-Recvd-Size: 4298 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf42.hostedemail.com (Postfix) with ESMTP for ; Fri, 27 Nov 2020 15:17:38 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 26425AC2D; Fri, 27 Nov 2020 15:17:37 +0000 (UTC) Subject: Re: [PATCH] mm/page_alloc: Do not isolate redundant pageblock To: Muchun Song , akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20201127141900.43348-1-songmuchun@bytedance.com> From: Vlastimil Babka Message-ID: <9e32e476-3812-2616-b2f5-a9b6f3531b8b@suse.cz> Date: Fri, 27 Nov 2020 16:17:36 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.5.0 MIME-Version: 1.0 In-Reply-To: <20201127141900.43348-1-songmuchun@bytedance.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit 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: On 11/27/20 3:19 PM, Muchun Song wrote: > Current pageblock isolation logic could isolate each pageblock individually > since commit d9dddbf55667 ("mm/page_alloc: prevent merging between isolated > and other pageblocks"). So we not need to concern about page allocator > merges buddies from different pageblocks and changes MIGRATE_ISOLATE to > some other migration type. Yeah, that should be the case now. > Signed-off-by: Muchun Song > --- > mm/page_alloc.c | 26 ++++++++------------------ > 1 file changed, 8 insertions(+), 18 deletions(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index cefbef32bf4a..608a2c2b8ab7 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -8313,16 +8313,14 @@ struct page *has_unmovable_pages(struct zone *zone, struct page *page, > } > > #ifdef CONFIG_CONTIG_ALLOC > -static unsigned long pfn_max_align_down(unsigned long pfn) > +static unsigned long pfn_align_down(unsigned long pfn) > { > - return pfn & ~(max_t(unsigned long, MAX_ORDER_NR_PAGES, > - pageblock_nr_pages) - 1); > + return pfn & ~(pageblock_nr_pages - 1); > } > > -static unsigned long pfn_max_align_up(unsigned long pfn) > +static unsigned long pfn_align_up(unsigned long pfn) > { > - return ALIGN(pfn, max_t(unsigned long, MAX_ORDER_NR_PAGES, > - pageblock_nr_pages)); > + return ALIGN(pfn, pageblock_nr_pages); > } How bout just removing these wrappers completely and using ALIGN and ALIGN_DOWN directly, as there are just two uses for each? > /* [start, end) must belong to a single zone. */ > @@ -8415,14 +8413,6 @@ int alloc_contig_range(unsigned long start, unsigned long end, > INIT_LIST_HEAD(&cc.migratepages); > > /* > - * What we do here is we mark all pageblocks in range as > - * MIGRATE_ISOLATE. Because pageblock and max order pages may > - * have different sizes, and due to the way page allocator > - * work, we align the range to biggest of the two pages so > - * that page allocator won't try to merge buddies from > - * different pageblocks and change MIGRATE_ISOLATE to some > - * other migration type. > - * > * Once the pageblocks are marked as MIGRATE_ISOLATE, we > * migrate the pages from an unaligned range (ie. pages that > * we are interested in). This will put all the pages in > @@ -8438,8 +8428,8 @@ int alloc_contig_range(unsigned long start, unsigned long end, > * put back to page allocator so that buddy can use them. > */ > > - ret = start_isolate_page_range(pfn_max_align_down(start), > - pfn_max_align_up(end), migratetype, 0); > + ret = start_isolate_page_range(pfn_align_down(start), pfn_align_up(end), > + migratetype, 0); > if (ret) > return ret; > > @@ -8522,8 +8512,8 @@ int alloc_contig_range(unsigned long start, unsigned long end, > free_contig_range(end, outer_end - end); > > done: > - undo_isolate_page_range(pfn_max_align_down(start), > - pfn_max_align_up(end), migratetype); > + undo_isolate_page_range(pfn_align_down(start), pfn_align_up(end), > + migratetype); > return ret; > } > EXPORT_SYMBOL(alloc_contig_range); >