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 21511CD37B0 for ; Mon, 18 Sep 2023 07:34:29 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A9C486B029F; Mon, 18 Sep 2023 03:34:28 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A4C886B02A1; Mon, 18 Sep 2023 03:34:28 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 913FC6B02A2; Mon, 18 Sep 2023 03:34:28 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 80C936B029F for ; Mon, 18 Sep 2023 03:34:28 -0400 (EDT) Received: from smtpin22.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 5088EC0C0F for ; Mon, 18 Sep 2023 07:34:28 +0000 (UTC) X-FDA: 81248905416.22.9536ECE Received: from out30-131.freemail.mail.aliyun.com (out30-131.freemail.mail.aliyun.com [115.124.30.131]) by imf23.hostedemail.com (Postfix) with ESMTP id 3CD2214001C for ; Mon, 18 Sep 2023 07:34:24 +0000 (UTC) Authentication-Results: imf23.hostedemail.com; dkim=none; spf=pass (imf23.hostedemail.com: domain of baolin.wang@linux.alibaba.com designates 115.124.30.131 as permitted sender) smtp.mailfrom=baolin.wang@linux.alibaba.com; dmarc=pass (policy=none) header.from=alibaba.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1695022466; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=QuvWsgwUeJAXZIQC6r5e72FY3X2ynn4ScAoGALsSzK8=; b=IkxE/SlDBpH4KWVWAxBxcydzU+vTUB+2JHwsDpW98WA6utaIY5KdoJUMn9uwyFp61erPie Ar3/Cswy0zesTIsCpPyKfYKVtqr9kJCJ68/TYEwKr5y6TpRLpgY3cuxhxolZSaM9T/1LLG fnfKnAZa64e1v/a3hrxBkqxGtsyo2Ag= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1695022466; a=rsa-sha256; cv=none; b=Ha79/LOML6Zt1oeUPW/zcSnGd3hIKAY3ctsAaXIT8mlRiUoGa/cYVQFqmxXe2Y4WihL+nA q8x0sCjo3yx4956TN233txzEJq2b/hKHbSOckPFwGK6RW4yovfq9bQjRHInSvGzsPYTm9D 9lf2D383xx13I2mDPBKYaANaCcg82rE= ARC-Authentication-Results: i=1; imf23.hostedemail.com; dkim=none; spf=pass (imf23.hostedemail.com: domain of baolin.wang@linux.alibaba.com designates 115.124.30.131 as permitted sender) smtp.mailfrom=baolin.wang@linux.alibaba.com; dmarc=pass (policy=none) header.from=alibaba.com X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R181e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046059;MF=baolin.wang@linux.alibaba.com;NM=1;PH=DS;RN=17;SR=0;TI=SMTPD_---0VsIAQZk_1695022459; Received: from 30.97.48.66(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0VsIAQZk_1695022459) by smtp.aliyun-inc.com; Mon, 18 Sep 2023 15:34:21 +0800 Message-ID: <28f76c7c-4b84-5e08-2f27-07592d8078a2@linux.alibaba.com> Date: Mon, 18 Sep 2023 15:34:25 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.15.0 Subject: Re: [RFC PATCH 2/4] mm/compaction: optimize >0 order folio compaction with free page split. To: Zi Yan , linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: Ryan Roberts , Andrew Morton , "Matthew Wilcox (Oracle)" , David Hildenbrand , "Yin, Fengwei" , Yu Zhao , Vlastimil Babka , Johannes Weiner , Kemeng Shi , Mel Gorman , Rohan Puri , Mcgrof Chamberlain , Adam Manzanares , John Hubbard References: <20230912162815.440749-1-zi.yan@sent.com> <20230912162815.440749-3-zi.yan@sent.com> From: Baolin Wang In-Reply-To: <20230912162815.440749-3-zi.yan@sent.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Stat-Signature: iemkupizywhwqntirckhocd4zpq5ture X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: 3CD2214001C X-Rspam-User: X-HE-Tag: 1695022464-421035 X-HE-Meta: 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 j1WGJ3Uu hInhbnFqK+jVP6DKPvX9ZAAuP9jVRlHrByO7Tgslg5njZKwUCFZrtQEdP5Tj2hTOBOHAD0IrjyZ2nrZt7Bz5Gm/H6QmMoH4jNqN4r5ruhuZeVj6hi2GeE2cb8V5lpfXWi+rZlCPcH8xKvPIPEbghF1/PUURs0NK8q/35WyMF4FVYhyzwpqkVTePcL7Q== 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 9/13/2023 12:28 AM, Zi Yan wrote: > From: Zi Yan > > During migration in a memory compaction, free pages are placed in an array > of page lists based on their order. But the desired free page order (i.e., > the order of a source page) might not be always present, thus leading to > migration failures. Split a high order free pages when source migration > page has a lower order to increase migration successful rate. > > Note: merging free pages when a migration fails and a lower order free > page is returned via compaction_free() is possible, but there is too much > work. Since the free pages are not buddy pages, it is hard to identify > these free pages using existing PFN-based page merging algorithm. > > Signed-off-by: Zi Yan > --- > mm/compaction.c | 40 +++++++++++++++++++++++++++++++++++++++- > 1 file changed, 39 insertions(+), 1 deletion(-) > > diff --git a/mm/compaction.c b/mm/compaction.c > index 868e92e55d27..45747ab5f380 100644 > --- a/mm/compaction.c > +++ b/mm/compaction.c > @@ -1801,9 +1801,46 @@ static struct folio *compaction_alloc(struct folio *src, unsigned long data) > struct compact_control *cc = (struct compact_control *)data; > struct folio *dst; > int order = folio_order(src); > + bool has_isolated_pages = false; > > +again: > if (!cc->freepages[order].nr_free) { > - isolate_freepages(cc); > + int i; > + > + for (i = order + 1; i <= MAX_ORDER; i++) { > + if (cc->freepages[i].nr_free) { > + struct page *freepage = > + list_first_entry(&cc->freepages[i].pages, > + struct page, lru); > + > + int start_order = i; > + unsigned long size = 1 << start_order; > + > + list_del(&freepage->lru); > + cc->freepages[i].nr_free--; > + > + while (start_order > order) { > + start_order--; > + size >>= 1; > + > + list_add(&freepage[size].lru, > + &cc->freepages[start_order].pages); > + cc->freepages[start_order].nr_free++; > + set_page_private(&freepage[size], start_order); IIUC, these split pages should also call functions to initialize? e.g. prep_compound_page()? > + } > + post_alloc_hook(freepage, order, __GFP_MOVABLE); > + if (order) > + prep_compound_page(freepage, order); > + dst = page_folio(freepage); > + goto done; > + } > + } > + if (!has_isolated_pages) { > + isolate_freepages(cc); > + has_isolated_pages = true; > + goto again; > + } > + > if (!cc->freepages[order].nr_free) > return NULL; > } > @@ -1814,6 +1851,7 @@ static struct folio *compaction_alloc(struct folio *src, unsigned long data) > post_alloc_hook(&dst->page, order, __GFP_MOVABLE); > if (order) > prep_compound_page(&dst->page, order); > +done: > cc->nr_freepages -= 1 << order; > return dst; > }