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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,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 4B39DC35250 for ; Mon, 10 Feb 2020 06:02:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2714320838 for ; Mon, 10 Feb 2020 06:02:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727434AbgBJGCj (ORCPT ); Mon, 10 Feb 2020 01:02:39 -0500 Received: from mga12.intel.com ([192.55.52.136]:7451 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726103AbgBJGCi (ORCPT ); Mon, 10 Feb 2020 01:02:38 -0500 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 09 Feb 2020 22:02:38 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,424,1574150400"; d="scan'208";a="405480581" Received: from richard.sh.intel.com (HELO localhost) ([10.239.159.54]) by orsmga005.jf.intel.com with ESMTP; 09 Feb 2020 22:02:36 -0800 Date: Mon, 10 Feb 2020 14:02:53 +0800 From: Wei Yang To: Baoquan He Cc: Wei Yang , linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org, dan.j.williams@intel.com, david@redhat.com Subject: Re: [PATCH 2/7] mm/sparse.c: Introduce a new function clear_subsection_map() Message-ID: <20200210060253.GE7326@richard> Reply-To: Wei Yang References: <20200209104826.3385-1-bhe@redhat.com> <20200209104826.3385-3-bhe@redhat.com> <20200209230713.GB7326@richard> <20200210033627.GZ8965@MiWiFi-R3L-srv> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200210033627.GZ8965@MiWiFi-R3L-srv> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 10, 2020 at 11:36:27AM +0800, Baoquan He wrote: >On 02/10/20 at 07:07am, Wei Yang wrote: >> On Sun, Feb 09, 2020 at 06:48:21PM +0800, Baoquan He wrote: >> >Wrap the codes clearing subsection map of one memory region in >> >section_deactivate() into clear_subsection_map(). >> > >> >> Patch 1 and 2 server the same purpose -- to #ifdef the VMEMMAP. > >Hmm, I didn't say patch 1 and 2 are preparation works because they had >better be done even if we don't take off subsection map from >SPARSEMEM|!VMEMMAP case. Wrapping the subsection map filling and clearing >codes into separate new functions, can make section_activate() and >section_deactivate() much clearer on code logic. > >If you don't mind, I will keep them for now, and see what other people >will say. No objection. > >Thanks >Baoquan > >> >> >--- >> > mm/sparse.c | 44 +++++++++++++++++++++++++++++++++++++------- >> > 1 file changed, 37 insertions(+), 7 deletions(-) >> > >> >diff --git a/mm/sparse.c b/mm/sparse.c >> >index 9ad741ccbeb6..696f6b9f706e 100644 >> >--- a/mm/sparse.c >> >+++ b/mm/sparse.c >> >@@ -726,14 +726,25 @@ static void free_map_bootmem(struct page *memmap) >> > } >> > #endif /* CONFIG_SPARSEMEM_VMEMMAP */ >> > >> >-static void section_deactivate(unsigned long pfn, unsigned long nr_pages, >> >- struct vmem_altmap *altmap) >> >+/** >> >+ * clear_subsection_map - Clear subsection map of one memory region >> >+ * >> >+ * @pfn - start pfn of the memory range >> >+ * @nr_pages - number of pfns to add in the region >> >+ * >> >+ * This is only intended for hotplug, and clear the related subsection >> >+ * map inside one section. >> >+ * >> >+ * Return: >> >+ * * -EINVAL - Section already deactived. >> >+ * * 0 - Subsection map is emptied. >> >+ * * 1 - Subsection map is not empty. >> >+ */ >> >+static int clear_subsection_map(unsigned long pfn, unsigned long nr_pages) >> > { >> > DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 }; >> > DECLARE_BITMAP(tmp, SUBSECTIONS_PER_SECTION) = { 0 }; >> > struct mem_section *ms = __pfn_to_section(pfn); >> >- bool section_is_early = early_section(ms); >> >- struct page *memmap = NULL; >> > unsigned long *subsection_map = ms->usage >> > ? &ms->usage->subsection_map[0] : NULL; >> > >> >@@ -744,8 +755,28 @@ static void section_deactivate(unsigned long pfn, unsigned long nr_pages, >> > if (WARN(!subsection_map || !bitmap_equal(tmp, map, SUBSECTIONS_PER_SECTION), >> > "section already deactivated (%#lx + %ld)\n", >> > pfn, nr_pages)) >> >- return; >> >+ return -EINVAL; >> >+ >> >+ bitmap_xor(subsection_map, map, subsection_map, SUBSECTIONS_PER_SECTION); >> > >> >+ if (bitmap_empty(subsection_map, SUBSECTIONS_PER_SECTION)) >> >+ return 0; >> >+ >> >+ return 1; >> >+} >> >+ >> >+static void section_deactivate(unsigned long pfn, unsigned long nr_pages, >> >+ struct vmem_altmap *altmap) >> >+{ >> >+ struct mem_section *ms = __pfn_to_section(pfn); >> >+ bool section_is_early = early_section(ms); >> >+ struct page *memmap = NULL; >> >+ int rc; >> >+ >> >+ >> >+ rc = clear_subsection_map(pfn, nr_pages); >> >+ if(IS_ERR_VALUE((unsigned long)rc)) >> >+ return; >> > /* >> > * There are 3 cases to handle across two configurations >> > * (SPARSEMEM_VMEMMAP={y,n}): >> >@@ -763,8 +794,7 @@ static void section_deactivate(unsigned long pfn, unsigned long nr_pages, >> > * >> > * For 2/ and 3/ the SPARSEMEM_VMEMMAP={y,n} cases are unified >> > */ >> >- bitmap_xor(subsection_map, map, subsection_map, SUBSECTIONS_PER_SECTION); >> >- if (bitmap_empty(subsection_map, SUBSECTIONS_PER_SECTION)) { >> >+ if (!rc) { >> > unsigned long section_nr = pfn_to_section_nr(pfn); >> > >> > /* >> >-- >> >2.17.2 >> >> -- >> Wei Yang >> Help you, Help me >> -- Wei Yang Help you, Help me