From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f197.google.com (mail-pf0-f197.google.com [209.85.192.197]) by kanga.kvack.org (Postfix) with ESMTP id 9207F6B0003 for ; Mon, 26 Mar 2018 18:30:42 -0400 (EDT) Received: by mail-pf0-f197.google.com with SMTP id c65so4234624pfa.5 for ; Mon, 26 Mar 2018 15:30:42 -0700 (PDT) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id j20sor4979339pfa.83.2018.03.26.15.30.41 for (Google Transport Security); Mon, 26 Mar 2018 15:30:41 -0700 (PDT) Date: Tue, 27 Mar 2018 06:30:34 +0800 From: Wei Yang Subject: Re: [PATCH 1/2] mm/sparse: pass the __highest_present_section_nr + 1 to alloc_func() Message-ID: <20180326223034.GA78976@WeideMacBook-Pro.local> Reply-To: Wei Yang References: <20180326081956.75275-1-richard.weiyang@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: David Rientjes Cc: Wei Yang , dave.hansen@linux.intel.com, akpm@linux-foundation.org, mhocko@suse.com, linux-mm@kvack.org On Mon, Mar 26, 2018 at 01:56:50PM -0700, David Rientjes wrote: >On Mon, 26 Mar 2018, Wei Yang wrote: > >> In 'commit c4e1be9ec113 ("mm, sparsemem: break out of loops early")', >> __highest_present_section_nr is introduced to reduce the loop counts for >> present section. This is also helpful for usemap and memmap allocation. >> >> This patch uses __highest_present_section_nr + 1 to optimize the loop. >> >> Signed-off-by: Wei Yang >> --- >> mm/sparse.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/mm/sparse.c b/mm/sparse.c >> index 7af5e7a92528..505050346249 100644 >> --- a/mm/sparse.c >> +++ b/mm/sparse.c >> @@ -561,7 +561,7 @@ static void __init alloc_usemap_and_memmap(void (*alloc_func) >> map_count = 1; >> } >> /* ok, last chunk */ >> - alloc_func(data, pnum_begin, NR_MEM_SECTIONS, >> + alloc_func(data, pnum_begin, __highest_present_section_nr+1, >> map_count, nodeid_begin); >> } >> > >What happens if s/NR_MEM_SECTIONS/pnum/? I have tried this :-) The last pnum is -1 from next_present_section_nr(). -- Wei Yang Help you, Help me