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=-8.4 required=3.0 tests=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=unavailable 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 45922C3B186 for ; Wed, 12 Feb 2020 11:27:02 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id F19D4206D7 for ; Wed, 12 Feb 2020 11:27:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="HepAVfOj" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F19D4206D7 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 995CA6B0431; Wed, 12 Feb 2020 06:27:01 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 920986B0433; Wed, 12 Feb 2020 06:27:01 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 80D806B0434; Wed, 12 Feb 2020 06:27:01 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0075.hostedemail.com [216.40.44.75]) by kanga.kvack.org (Postfix) with ESMTP id 605D66B0431 for ; Wed, 12 Feb 2020 06:27:01 -0500 (EST) Received: from smtpin20.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 31FF5381E for ; Wed, 12 Feb 2020 11:27:01 +0000 (UTC) X-FDA: 76481248242.20.park27_777043c41df2a X-HE-Tag: park27_777043c41df2a X-Filterd-Recvd-Size: 13072 Received: from us-smtp-delivery-1.mimecast.com (us-smtp-1.mimecast.com [205.139.110.61]) by imf32.hostedemail.com (Postfix) with ESMTP for ; Wed, 12 Feb 2020 11:27:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1581506820; 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=sOBpuSxMPuJUbkuLPHqFKoJm4N6xAPNq3p7qQaPewdE=; b=HepAVfOjX3cnwjsYzesELkOMGDbV3LnhPyI+AUKvImd5SiaXEmf+IBNPIkBeJuuCC6lIqB iQf5vw41lqeYcZAbozXQK4RBaMgKMPd7x9XKzGZkvumerk0A16Yq0FIFlOtF5L+nq2YitR bnuM37ceEeDb0v7JIdeI9BiOHqStZ/s= 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-198-xuJ5a9kFN6SbgiyplfDCAQ-1; Wed, 12 Feb 2020 06:26:55 -0500 X-MC-Unique: xuJ5a9kFN6SbgiyplfDCAQ-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 10F768017CC; Wed, 12 Feb 2020 11:26:54 +0000 (UTC) Received: from localhost (ovpn-12-47.pek2.redhat.com [10.72.12.47]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 4A5F39006B; Wed, 12 Feb 2020 11:26:49 +0000 (UTC) Date: Wed, 12 Feb 2020 19:26:41 +0800 From: Baoquan He To: David Hildenbrand Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org, dan.j.williams@intel.com, richardw.yang@linux.intel.com Subject: Re: [PATCH 3/7] mm/sparse.c: only use subsection map in VMEMMAP case Message-ID: <20200212112641.GJ26758@MiWiFi-R3L-srv> References: <20200209104826.3385-1-bhe@redhat.com> <20200209104826.3385-4-bhe@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 02/11/20 at 03:43pm, David Hildenbrand wrote: > On 09.02.20 11:48, Baoquan He wrote: > > Currently, subsection map is used when SPARSEMEM is enabled, including > > VMEMMAP case and !VMEMMAP case. However, subsection hotplug is not > > supported at all in SPARSEMEM|!VMEMMAP case, subsection map is unnecessary > > and misleading. Let's adjust code to only allow subsection map being > > used in SPARSEMEM|VMEMMAP case. > > > > Signed-off-by: Baoquan He > > --- > > include/linux/mmzone.h | 2 + > > mm/sparse.c | 231 ++++++++++++++++++++++------------------- > > 2 files changed, 124 insertions(+), 109 deletions(-) > > > > diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h > > index 462f6873905a..fc0de3a9a51e 100644 > > --- a/include/linux/mmzone.h > > +++ b/include/linux/mmzone.h > > @@ -1185,7 +1185,9 @@ static inline unsigned long section_nr_to_pfn(unsigned long sec) > > #define SUBSECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SUBSECTION_MASK) > > > > struct mem_section_usage { > > +#ifdef CONFIG_SPARSEMEM_VMEMMAP > > DECLARE_BITMAP(subsection_map, SUBSECTIONS_PER_SECTION); > > +#endif > > /* See declaration of similar field in struct zone */ > > unsigned long pageblock_flags[0]; > > }; > > diff --git a/mm/sparse.c b/mm/sparse.c > > index 696f6b9f706e..cf55d272d0a9 100644 > > --- a/mm/sparse.c > > +++ b/mm/sparse.c > > @@ -209,41 +209,6 @@ static inline unsigned long first_present_section_nr(void) > > return next_present_section_nr(-1); > > } > > > > -static void subsection_mask_set(unsigned long *map, unsigned long pfn, > > - unsigned long nr_pages) > > -{ > > - int idx = subsection_map_index(pfn); > > - int end = subsection_map_index(pfn + nr_pages - 1); > > - > > - bitmap_set(map, idx, end - idx + 1); > > -} > > - > > -void __init subsection_map_init(unsigned long pfn, unsigned long nr_pages) > > -{ > > - int end_sec = pfn_to_section_nr(pfn + nr_pages - 1); > > - unsigned long nr, start_sec = pfn_to_section_nr(pfn); > > - > > - if (!nr_pages) > > - return; > > - > > - for (nr = start_sec; nr <= end_sec; nr++) { > > - struct mem_section *ms; > > - unsigned long pfns; > > - > > - pfns = min(nr_pages, PAGES_PER_SECTION > > - - (pfn & ~PAGE_SECTION_MASK)); > > - ms = __nr_to_section(nr); > > - subsection_mask_set(ms->usage->subsection_map, pfn, pfns); > > - > > - pr_debug("%s: sec: %lu pfns: %lu set(%d, %d)\n", __func__, nr, > > - pfns, subsection_map_index(pfn), > > - subsection_map_index(pfn + pfns - 1)); > > - > > - pfn += pfns; > > - nr_pages -= pfns; > > - } > > -} > > - > > /* Record a memory area against a node. */ > > void __init memory_present(int nid, unsigned long start, unsigned long end) > > { > > @@ -432,12 +397,134 @@ static unsigned long __init section_map_size(void) > > return ALIGN(sizeof(struct page) * PAGES_PER_SECTION, PMD_SIZE); > > } > > > > +static void subsection_mask_set(unsigned long *map, unsigned long pfn, > > + unsigned long nr_pages) > > +{ > > + int idx = subsection_map_index(pfn); > > + int end = subsection_map_index(pfn + nr_pages - 1); > > + > > + bitmap_set(map, idx, end - idx + 1); > > +} > > + > > +void __init subsection_map_init(unsigned long pfn, unsigned long nr_pages) > > +{ > > + int end_sec = pfn_to_section_nr(pfn + nr_pages - 1); > > + unsigned long nr, start_sec = pfn_to_section_nr(pfn); > > + > > + if (!nr_pages) > > + return; > > + > > + for (nr = start_sec; nr <= end_sec; nr++) { > > + struct mem_section *ms; > > + unsigned long pfns; > > + > > + pfns = min(nr_pages, PAGES_PER_SECTION > > + - (pfn & ~PAGE_SECTION_MASK)); > > + ms = __nr_to_section(nr); > > + subsection_mask_set(ms->usage->subsection_map, pfn, pfns); > > + > > + pr_debug("%s: sec: %lu pfns: %lu set(%d, %d)\n", __func__, nr, > > + pfns, subsection_map_index(pfn), > > + subsection_map_index(pfn + pfns - 1)); > > + > > + pfn += pfns; > > + nr_pages -= pfns; > > + } > > +} > > + > > +/** > > + * 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); > > + unsigned long *subsection_map = ms->usage > > + ? &ms->usage->subsection_map[0] : NULL; > > + > > + subsection_mask_set(map, pfn, nr_pages); > > + if (subsection_map) > > + bitmap_and(tmp, map, subsection_map, SUBSECTIONS_PER_SECTION); > > + > > + if (WARN(!subsection_map || !bitmap_equal(tmp, map, SUBSECTIONS_PER_SECTION), > > + "section already deactivated (%#lx + %ld)\n", > > + pfn, nr_pages)) > > + return -EINVAL; > > + > > + bitmap_xor(subsection_map, map, subsection_map, SUBSECTIONS_PER_SECTION); > > + > > + if (bitmap_empty(subsection_map, SUBSECTIONS_PER_SECTION)) > > + return 0; > > + > > + return 1; > > +} > > + > > +/** > > + * fill_subsection_map - fill subsection map of a memory region > > + * @pfn - start pfn of the memory range > > + * @nr_pages - number of pfns to add in the region > > + * > > + * This clears the related subsection map inside one section, and only > > + * intended for hotplug. > > + * > > + * Return: > > + * * 0 - On success. > > + * * -EINVAL - Invalid memory region. > > + * * -EEXIST - Subsection map has been set. > > + */ > > +static int fill_subsection_map(unsigned long pfn, unsigned long nr_pages) > > +{ > > + struct mem_section *ms = __pfn_to_section(pfn); > > + DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 }; > > + unsigned long *subsection_map; > > + int rc = 0; > > + > > + subsection_mask_set(map, pfn, nr_pages); > > + > > + subsection_map = &ms->usage->subsection_map[0]; > > + > > + if (bitmap_empty(map, SUBSECTIONS_PER_SECTION)) > > + rc = -EINVAL; > > + else if (bitmap_intersects(map, subsection_map, SUBSECTIONS_PER_SECTION)) > > + rc = -EEXIST; > > + else > > + bitmap_or(subsection_map, map, subsection_map, > > + SUBSECTIONS_PER_SECTION); > > + > > + return rc; > > +} > > + > > #else > > static unsigned long __init section_map_size(void) > > { > > return PAGE_ALIGN(sizeof(struct page) * PAGES_PER_SECTION); > > } > > > > +void __init subsection_map_init(unsigned long pfn, unsigned long nr_pages) > > +{ > > +} > > + > > +static int clear_subsection_map(unsigned long pfn, unsigned long nr_pages) > > +{ > > + return 0; > > +} > > +static int fill_subsection_map(unsigned long pfn, unsigned long nr_pages) > > +{ > > + return 0; > > +} > > + > > struct page __init *__populate_section_memmap(unsigned long pfn, > > unsigned long nr_pages, int nid, struct vmem_altmap *altmap) > > { > > @@ -726,45 +813,6 @@ static void free_map_bootmem(struct page *memmap) > > } > > #endif /* CONFIG_SPARSEMEM_VMEMMAP */ > > > > -/** > > - * 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); > > - unsigned long *subsection_map = ms->usage > > - ? &ms->usage->subsection_map[0] : NULL; > > - > > - subsection_mask_set(map, pfn, nr_pages); > > - if (subsection_map) > > - bitmap_and(tmp, map, subsection_map, SUBSECTIONS_PER_SECTION); > > - > > - if (WARN(!subsection_map || !bitmap_equal(tmp, map, SUBSECTIONS_PER_SECTION), > > - "section already deactivated (%#lx + %ld)\n", > > - pfn, nr_pages)) > > - 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) > > { > > @@ -818,41 +866,6 @@ static void section_deactivate(unsigned long pfn, unsigned long nr_pages, > > depopulate_section_memmap(pfn, nr_pages, altmap); > > } > > > > -/** > > - * fill_subsection_map - fill subsection map of a memory region > > - * @pfn - start pfn of the memory range > > - * @nr_pages - number of pfns to add in the region > > - * > > - * This clears the related subsection map inside one section, and only > > - * intended for hotplug. > > - * > > - * Return: > > - * * 0 - On success. > > - * * -EINVAL - Invalid memory region. > > - * * -EEXIST - Subsection map has been set. > > - */ > > -static int fill_subsection_map(unsigned long pfn, unsigned long nr_pages) > > -{ > > - struct mem_section *ms = __pfn_to_section(pfn); > > - DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 }; > > - unsigned long *subsection_map; > > - int rc = 0; > > - > > - subsection_mask_set(map, pfn, nr_pages); > > - > > - subsection_map = &ms->usage->subsection_map[0]; > > - > > - if (bitmap_empty(map, SUBSECTIONS_PER_SECTION)) > > - rc = -EINVAL; > > - else if (bitmap_intersects(map, subsection_map, SUBSECTIONS_PER_SECTION)) > > - rc = -EEXIST; > > - else > > - bitmap_or(subsection_map, map, subsection_map, > > - SUBSECTIONS_PER_SECTION); > > - > > - return rc; > > -} > > - > > static struct page * __meminit section_activate(int nid, unsigned long pfn, > > unsigned long nr_pages, struct vmem_altmap *altmap) > > { > > > > I'd prefer adding more ifdefs to avoid heavy code movement. Would make > it much easier to review :) OK, I did it in the first place. Later I think putting all subsectin related handling into one place makes code look better. Now I understand it may make patch format messy. I will adjust the place to make reviewing easier. Thanks for your great suggestion.