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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 10AECC433C1 for ; Mon, 22 Mar 2021 14:32:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C4EAB6196C for ; Mon, 22 Mar 2021 14:32:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230193AbhCVObp (ORCPT ); Mon, 22 Mar 2021 10:31:45 -0400 Received: from mx2.suse.de ([195.135.220.15]:37960 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229893AbhCVObI (ORCPT ); Mon, 22 Mar 2021 10:31:08 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1616423467; h=from:from:reply-to: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=CpPLEqSIKAx6LCad+2eiCBK8qg/o/11mDrcvfFKDJWk=; b=ji/kO1BsoNTVCCNONFSEuQtUw4jSzJX56+SiBHCRVIPO9jNqYTKgymtfAsQUNhLUtTmtI+ +jn7603DyUTYfXgKFLoHf8nXm6iMZRMCjKAgT7OZZQr7eP84vLfG+Q/BAj5b1ap/kEL/J5 vLfDBjllUTVr+bWf2pLvF5l6a6Pmvi4= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 3BDCAACA8; Mon, 22 Mar 2021 14:31:07 +0000 (UTC) Date: Mon, 22 Mar 2021 15:31:01 +0100 From: Michal Hocko To: Mike Kravetz Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Shakeel Butt , Oscar Salvador , David Hildenbrand , Muchun Song , David Rientjes , Miaohe Lin , Peter Zijlstra , Matthew Wilcox , HORIGUCHI NAOYA , "Aneesh Kumar K . V" , Waiman Long , Peter Xu , Mina Almasry , Andrew Morton Subject: Re: [RFC PATCH 5/8] hugetlb: change free_pool_huge_page to remove_pool_huge_page Message-ID: References: <20210319224209.150047-1-mike.kravetz@oracle.com> <20210319224209.150047-6-mike.kravetz@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210319224209.150047-6-mike.kravetz@oracle.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri 19-03-21 15:42:06, Mike Kravetz wrote: [...] > @@ -2090,9 +2084,15 @@ static void return_unused_surplus_pages(struct hstate *h, > while (nr_pages--) { > h->resv_huge_pages--; > unused_resv_pages--; > - if (!free_pool_huge_page(h, &node_states[N_MEMORY], 1)) > + page = remove_pool_huge_page(h, &node_states[N_MEMORY], 1); > + if (!page) > goto out; > - cond_resched_lock(&hugetlb_lock); > + > + /* Drop lock and free page to buddy as it could sleep */ > + spin_unlock(&hugetlb_lock); > + update_and_free_page(h, page); > + cond_resched(); > + spin_lock(&hugetlb_lock); > } > > out: This is likely a matter of taste but the repeated pattern of unlock, update_and_free_page, cond_resched and lock seems rather clumsy. Would it be slightly better/nicer to remove_pool_huge_page into a list_head under a single lock invocation and then free up the whole lot after the lock is dropped? -- Michal Hocko SUSE Labs