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=-6.9 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 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 25951C3F2C6 for ; Sat, 7 Mar 2020 08:43:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0005D2073D for ; Sat, 7 Mar 2020 08:43:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="CvmAI5Bp" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726384AbgCGInB (ORCPT ); Sat, 7 Mar 2020 03:43:01 -0500 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:43458 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726139AbgCGInA (ORCPT ); Sat, 7 Mar 2020 03:43:00 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1583570580; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:in-reply-to:in-reply-to:references:references; bh=ATGhP0O/yOcpGwpVsSIMGv+3IgMHyX+tBlVYBmLZz4o=; b=CvmAI5BpmdDI5vcW3EProwPkjOslcBAsT6YHtz64SoDY1Y0RD5F2BNvoFW7PqQBRzdHz9D /TARgs00yONjem/21zPQuLOPUAkfosVG/u8Al13YrFnSyn8zGsL7Um84HsMzplhzI65ec5 n+GjV88JEu11DyC4Cchak2ZkP5CJxaI= 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-135-qzx1YR6pPu-_GvwELljK1Q-1; Sat, 07 Mar 2020 03:42:56 -0500 X-MC-Unique: qzx1YR6pPu-_GvwELljK1Q-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id CD5DB13F7; Sat, 7 Mar 2020 08:42:54 +0000 (UTC) Received: from MiWiFi-R3L-srv.redhat.com (ovpn-12-29.pek2.redhat.com [10.72.12.29]) by smtp.corp.redhat.com (Postfix) with ESMTP id 262465D9CA; Sat, 7 Mar 2020 08:42:48 +0000 (UTC) From: Baoquan He To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, akpm@linux-foundation.org, mhocko@suse.com, david@redhat.com, richardw.yang@linux.intel.com, dan.j.williams@intel.com, osalvador@suse.de, rppt@linux.ibm.com, bhe@redhat.com Subject: [PATCH v3 4/7] mm/sparse.c: only use subsection map in VMEMMAP case Date: Sat, 7 Mar 2020 16:42:26 +0800 Message-Id: <20200307084229.28251-5-bhe@redhat.com> In-Reply-To: <20200307084229.28251-1-bhe@redhat.com> References: <20200307084229.28251-1-bhe@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently, to support subsection aligned memory region adding for pmem, subsection map is added to track which subsection is present. However, config ZONE_DEVICE depends on SPARSEMEM_VMEMMAP. It means subsection map only makes sense when SPARSEMEM_VMEMMAP enabled. For the classic sparse, subsection map is meaningless and confusing. About the classic sparse which doesn't support subsection hotplug, Dan said it's more because the effort and maintenance burden outweighs the benefit. Besides, the current 64 bit ARCHes all enable SPARSEMEM_VMEMMAP_ENABLE by default. Combining the above reasons, no need to provide subsection map and the relevant handling for the classic sparse. Handle it with this patch. Signed-off-by: Baoquan He --- include/linux/mmzone.h | 2 ++ mm/sparse.c | 25 +++++++++++++++++++++++++ 2 files changed, 27 insertions(+) diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 42b77d3b68e8..f3f264826423 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -1143,7 +1143,9 @@ 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 d9dcd58d5c1d..2142045ab5c5 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -209,6 +209,7 @@ static inline unsigned long first_present_section_nr(void) return next_present_section_nr(-1); } +#ifdef CONFIG_SPARSEMEM_VMEMMAP static void subsection_mask_set(unsigned long *map, unsigned long pfn, unsigned long nr_pages) { @@ -243,6 +244,11 @@ void __init subsection_map_init(unsigned long pfn, unsigned long nr_pages) nr_pages -= pfns; } } +#else +void __init subsection_map_init(unsigned long pfn, unsigned long nr_pages) +{ +} +#endif /* Record a memory area against a node. */ void __init memory_present(int nid, unsigned long start, unsigned long end) @@ -726,6 +732,7 @@ static void free_map_bootmem(struct page *memmap) } #endif /* CONFIG_SPARSEMEM_VMEMMAP */ +#ifdef CONFIG_SPARSEMEM_VMEMMAP static int clear_subsection_map(unsigned long pfn, unsigned long nr_pages) { DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 }; @@ -753,6 +760,17 @@ static bool is_subsection_map_empty(struct mem_section *ms) return bitmap_empty(&ms->usage->subsection_map[0], SUBSECTIONS_PER_SECTION); } +#else +static int clear_subsection_map(unsigned long pfn, unsigned long nr_pages) +{ + return 0; +} + +static bool is_subsection_map_empty(struct mem_section *ms) +{ + return true; +} +#endif static void section_deactivate(unsigned long pfn, unsigned long nr_pages, struct vmem_altmap *altmap) @@ -809,6 +827,7 @@ static void section_deactivate(unsigned long pfn, unsigned long nr_pages, ms->section_mem_map = (unsigned long)NULL; } +#ifdef CONFIG_SPARSEMEM_VMEMMAP static int fill_subsection_map(unsigned long pfn, unsigned long nr_pages) { struct mem_section *ms = __pfn_to_section(pfn); @@ -830,6 +849,12 @@ static int fill_subsection_map(unsigned long pfn, unsigned long nr_pages) return rc; } +#else +static int fill_subsection_map(unsigned long pfn, unsigned long nr_pages) +{ + return 0; +} +#endif static struct page * __meminit section_activate(int nid, unsigned long pfn, unsigned long nr_pages, struct vmem_altmap *altmap) -- 2.17.2