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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_MUTT 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 494C6C4646B for ; Mon, 24 Jun 2019 23:01:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 25E9720663 for ; Mon, 24 Jun 2019 23:01:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728012AbfFXXBY (ORCPT ); Mon, 24 Jun 2019 19:01:24 -0400 Received: from mga12.intel.com ([192.55.52.136]:40541 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726551AbfFXXBY (ORCPT ); Mon, 24 Jun 2019 19:01:24 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 24 Jun 2019 16:01:24 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.63,413,1557212400"; d="scan'208";a="163454969" Received: from iweiny-desk2.sc.intel.com ([10.3.52.157]) by fmsmga007.fm.intel.com with ESMTP; 24 Jun 2019 16:01:24 -0700 Date: Mon, 24 Jun 2019 16:01:24 -0700 From: Ira Weiny To: Pingfan Liu Cc: Linux-mm@kvack.org, Andrew Morton , Mike Rapoport , "Kirill A. Shutemov" , Thomas Gleixner , John Hubbard , "Aneesh Kumar K.V" , Christoph Hellwig , Keith Busch , Mike Kravetz , LKML Subject: Re: [PATCHv2] mm/gup: speed up check_and_migrate_cma_pages() on huge page Message-ID: <20190624230123.GA24567@iweiny-DESK2.sc.intel.com> References: <1561349561-8302-1-git-send-email-kernelfans@gmail.com> <20190624044305.GA30102@iweiny-DESK2.sc.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.11.1 (2018-12-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 24, 2019 at 01:34:01PM +0800, Pingfan Liu wrote: > On Mon, Jun 24, 2019 at 1:32 PM Pingfan Liu wrote: > > > > On Mon, Jun 24, 2019 at 12:43 PM Ira Weiny wrote: > > > > > > On Mon, Jun 24, 2019 at 12:12:41PM +0800, Pingfan Liu wrote: > > > > Both hugetlb and thp locate on the same migration type of pageblock, since > > > > they are allocated from a free_list[]. Based on this fact, it is enough to > > > > check on a single subpage to decide the migration type of the whole huge > > > > page. By this way, it saves (2M/4K - 1) times loop for pmd_huge on x86, > > > > similar on other archs. > > > > > > > > Furthermore, when executing isolate_huge_page(), it avoid taking global > > > > hugetlb_lock many times, and meanless remove/add to the local link list > > > > cma_page_list. > > > > > > > > Signed-off-by: Pingfan Liu > > > > Cc: Andrew Morton > > > > Cc: Ira Weiny > > > > Cc: Mike Rapoport > > > > Cc: "Kirill A. Shutemov" > > > > Cc: Thomas Gleixner > > > > Cc: John Hubbard > > > > Cc: "Aneesh Kumar K.V" > > > > Cc: Christoph Hellwig > > > > Cc: Keith Busch > > > > Cc: Mike Kravetz > > > > Cc: Linux-kernel@vger.kernel.org > > > > --- > > > > mm/gup.c | 19 ++++++++++++------- > > > > 1 file changed, 12 insertions(+), 7 deletions(-) > > > > > > > > diff --git a/mm/gup.c b/mm/gup.c > > > > index ddde097..544f5de 100644 > > > > --- a/mm/gup.c > > > > +++ b/mm/gup.c > > > > @@ -1342,19 +1342,22 @@ static long check_and_migrate_cma_pages(struct task_struct *tsk, > > > > LIST_HEAD(cma_page_list); > > > > > > > > check_again: > > > > - for (i = 0; i < nr_pages; i++) { > > > > + for (i = 0; i < nr_pages;) { > > > > + > > > > + struct page *head = compound_head(pages[i]); > > > > + long step = 1; > > > > + > > > > + if (PageCompound(head)) > > > > + step = compound_order(head) - (pages[i] - head); > > > > > > Sorry if I missed this last time. compound_order() is not correct here. > > For thp, prep_transhuge_page()->prep_compound_page()->set_compound_order(). > > For smaller hugetlb, > > prep_new_huge_page()->prep_compound_page()->set_compound_order(). > > For gigantic page, prep_compound_gigantic_page()->set_compound_order(). > > > > Do I miss anything? > > > Oh, got it. It should be 1< > Thanks, > > Pingfan > > [...]