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=-11.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham 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 D27ECC433DF for ; Mon, 10 Aug 2020 02:17:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AD64B20709 for ; Mon, 10 Aug 2020 02:17:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="gsqQJx/s" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726412AbgHJCRu (ORCPT ); Sun, 9 Aug 2020 22:17:50 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:52743 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726335AbgHJCRu (ORCPT ); Sun, 9 Aug 2020 22:17:50 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1597025868; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=R2MnT5kb+LpTU4V51q+u3lkSdfkwWI/8ULUd0tphg34=; b=gsqQJx/s0+FYTig0nF6q4YeYaTSSsNzLsnFm57i7SDxK7IZoOkQ8DMOU1KysJFGREkQS2b y39KHC/d/8FcGkbRg74VDAEEi+fzz6QGBVMiwFHD/BOtlYSI/ltcKgnB0FBtzb8kzGj2ww jGOL4H7s7ZVkf8+3q1PjQeCgcDVgJyQ= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-296-ZRZezdKVMHCGu7w2amQERw-1; Sun, 09 Aug 2020 22:17:45 -0400 X-MC-Unique: ZRZezdKVMHCGu7w2amQERw-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id A1EF1800404; Mon, 10 Aug 2020 02:17:43 +0000 (UTC) Received: from localhost (ovpn-12-116.pek2.redhat.com [10.72.12.116]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 438345F1E4; Mon, 10 Aug 2020 02:17:40 +0000 (UTC) Date: Mon, 10 Aug 2020 10:17:37 +0800 From: Baoquan He To: Wei Yang , mhocko@kernel.org Cc: mike.kravetz@oracle.com, akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 10/10] mm/hugetlb: not necessary to abuse temporary page to workaround the nasty free_huge_page Message-ID: <20200810021737.GV14854@MiWiFi-R3L-srv> References: <20200807091251.12129-1-richard.weiyang@linux.alibaba.com> <20200807091251.12129-11-richard.weiyang@linux.alibaba.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200807091251.12129-11-richard.weiyang@linux.alibaba.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/07/20 at 05:12pm, Wei Yang wrote: > Let's always increase surplus_huge_pages and so that free_huge_page > could decrease it at free time. > > Signed-off-by: Wei Yang > --- > mm/hugetlb.c | 14 ++++++-------- > 1 file changed, 6 insertions(+), 8 deletions(-) > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index 1f2010c9dd8d..a0eb81e0e4c5 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -1913,21 +1913,19 @@ static struct page *alloc_surplus_huge_page(struct hstate *h, gfp_t gfp_mask, > return NULL; > > spin_lock(&hugetlb_lock); > + > + h->surplus_huge_pages++; > + h->surplus_huge_pages_node[page_to_nid(page)]++; > + > /* > * We could have raced with the pool size change. > * Double check that and simply deallocate the new page > - * if we would end up overcommiting the surpluses. Abuse > - * temporary page to workaround the nasty free_huge_page > - * codeflow > + * if we would end up overcommiting the surpluses. > */ > - if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) { > - SetPageHugeTemporary(page); Hmm, the temporary page way is taken intentionally in commit 9980d744a0428 ("mm, hugetlb: get rid of surplus page accounting tricks"). >From code, this is done inside hugetlb_lock holding, and the code flow is straightforward, should be safe. Adding Michal to CC. > + if (h->surplus_huge_pages > h->nr_overcommit_huge_pages) { > spin_unlock(&hugetlb_lock); > put_page(page); > return NULL; > - } else { > - h->surplus_huge_pages++; > - h->surplus_huge_pages_node[page_to_nid(page)]++; > } > > out_unlock: > -- > 2.20.1 (Apple Git-117) > >