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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 5AD87C282DA for ; Wed, 17 Apr 2019 18:52:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F2FC620663 for ; Wed, 17 Apr 2019 18:52:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732836AbfDQSwr (ORCPT ); Wed, 17 Apr 2019 14:52:47 -0400 Received: from mga11.intel.com ([192.55.52.93]:49601 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727340AbfDQSwr (ORCPT ); Wed, 17 Apr 2019 14:52:47 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Apr 2019 11:52:46 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,362,1549958400"; d="scan'208";a="135207423" Received: from dwillia2-desk3.jf.intel.com (HELO dwillia2-desk3.amr.corp.intel.com) ([10.54.39.16]) by orsmga008.jf.intel.com with ESMTP; 17 Apr 2019 11:52:45 -0700 Subject: [PATCH v6 01/12] mm/sparsemem: Introduce struct mem_section_usage From: Dan Williams To: akpm@linux-foundation.org Cc: Michal Hocko , Vlastimil Babka , Logan Gunthorpe , linux-mm@kvack.org, linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org, mhocko@suse.com, david@redhat.com Date: Wed, 17 Apr 2019 11:39:00 -0700 Message-ID: <155552634075.2015392.3371070426600230054.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <155552633539.2015392.2477781120122237934.stgit@dwillia2-desk3.amr.corp.intel.com> References: <155552633539.2015392.2477781120122237934.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.18-2-gc94f MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Towards enabling memory hotplug to track partial population of a section, introduce 'struct mem_section_usage'. A pointer to a 'struct mem_section_usage' instance replaces the existing pointer to a 'pageblock_flags' bitmap. Effectively it adds one more 'unsigned long' beyond the 'pageblock_flags' (usemap) allocation to house a new 'map_active' bitmap. The new bitmap enables the memory hot{plug,remove} implementation to act on incremental sub-divisions of a section. The primary motivation for this functionality is to support platforms that mix "System RAM" and "Persistent Memory" within a single section, or multiple PMEM ranges with different mapping lifetimes within a single section. The section restriction for hotplug has caused an ongoing saga of hacks and bugs for devm_memremap_pages() users. Beyond the fixups to teach existing paths how to retrieve the 'usemap' from a section, and updates to usemap allocation path, there are no expected behavior changes. Cc: Michal Hocko Cc: Vlastimil Babka Cc: Logan Gunthorpe Signed-off-by: Dan Williams --- include/linux/mmzone.h | 23 ++++++++++++-- mm/memory_hotplug.c | 18 ++++++----- mm/page_alloc.c | 2 + mm/sparse.c | 81 ++++++++++++++++++++++++------------------------ 4 files changed, 71 insertions(+), 53 deletions(-) diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 70394cabaf4e..f0bbd85dc19a 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -1160,6 +1160,19 @@ static inline unsigned long section_nr_to_pfn(unsigned long sec) #define SECTION_ALIGN_UP(pfn) (((pfn) + PAGES_PER_SECTION - 1) & PAGE_SECTION_MASK) #define SECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SECTION_MASK) +#define SECTION_ACTIVE_SIZE ((1UL << SECTION_SIZE_BITS) / BITS_PER_LONG) +#define SECTION_ACTIVE_MASK (~(SECTION_ACTIVE_SIZE - 1)) + +struct mem_section_usage { + /* + * SECTION_ACTIVE_SIZE portions of the section that are populated in + * the memmap + */ + unsigned long map_active; + /* See declaration of similar field in struct zone */ + unsigned long pageblock_flags[0]; +}; + struct page; struct page_ext; struct mem_section { @@ -1177,8 +1190,7 @@ struct mem_section { */ unsigned long section_mem_map; - /* See declaration of similar field in struct zone */ - unsigned long *pageblock_flags; + struct mem_section_usage *usage; #ifdef CONFIG_PAGE_EXTENSION /* * If SPARSEMEM, pgdat doesn't have page_ext pointer. We use @@ -1209,6 +1221,11 @@ extern struct mem_section **mem_section; extern struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT]; #endif +static inline unsigned long *section_to_usemap(struct mem_section *ms) +{ + return ms->usage->pageblock_flags; +} + static inline struct mem_section *__nr_to_section(unsigned long nr) { #ifdef CONFIG_SPARSEMEM_EXTREME @@ -1220,7 +1237,7 @@ static inline struct mem_section *__nr_to_section(unsigned long nr) return &mem_section[SECTION_NR_TO_ROOT(nr)][nr & SECTION_ROOT_MASK]; } extern int __section_nr(struct mem_section* ms); -extern unsigned long usemap_size(void); +extern size_t mem_section_usage_size(void); /* * We use the lower bits of the mem_map pointer to store diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 52fef4a81e4c..8b7415736d21 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -165,9 +165,10 @@ void put_page_bootmem(struct page *page) #ifndef CONFIG_SPARSEMEM_VMEMMAP static void register_page_bootmem_info_section(unsigned long start_pfn) { - unsigned long *usemap, mapsize, section_nr, i; + unsigned long mapsize, section_nr, i; struct mem_section *ms; struct page *page, *memmap; + struct mem_section_usage *usage; section_nr = pfn_to_section_nr(start_pfn); ms = __nr_to_section(section_nr); @@ -187,10 +188,10 @@ static void register_page_bootmem_info_section(unsigned long start_pfn) for (i = 0; i < mapsize; i++, page++) get_page_bootmem(section_nr, page, SECTION_INFO); - usemap = ms->pageblock_flags; - page = virt_to_page(usemap); + usage = ms->usage; + page = virt_to_page(usage); - mapsize = PAGE_ALIGN(usemap_size()) >> PAGE_SHIFT; + mapsize = PAGE_ALIGN(mem_section_usage_size()) >> PAGE_SHIFT; for (i = 0; i < mapsize; i++, page++) get_page_bootmem(section_nr, page, MIX_SECTION_INFO); @@ -199,9 +200,10 @@ static void register_page_bootmem_info_section(unsigned long start_pfn) #else /* CONFIG_SPARSEMEM_VMEMMAP */ static void register_page_bootmem_info_section(unsigned long start_pfn) { - unsigned long *usemap, mapsize, section_nr, i; + unsigned long mapsize, section_nr, i; struct mem_section *ms; struct page *page, *memmap; + struct mem_section_usage *usage; section_nr = pfn_to_section_nr(start_pfn); ms = __nr_to_section(section_nr); @@ -210,10 +212,10 @@ static void register_page_bootmem_info_section(unsigned long start_pfn) register_page_bootmem_memmap(section_nr, memmap, PAGES_PER_SECTION); - usemap = ms->pageblock_flags; - page = virt_to_page(usemap); + usage = ms->usage; + page = virt_to_page(usage); - mapsize = PAGE_ALIGN(usemap_size()) >> PAGE_SHIFT; + mapsize = PAGE_ALIGN(mem_section_usage_size()) >> PAGE_SHIFT; for (i = 0; i < mapsize; i++, page++) get_page_bootmem(section_nr, page, MIX_SECTION_INFO); diff --git a/mm/page_alloc.c b/mm/page_alloc.c index deea16489e2b..f671401a7c0b 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -390,7 +390,7 @@ static inline unsigned long *get_pageblock_bitmap(struct page *page, unsigned long pfn) { #ifdef CONFIG_SPARSEMEM - return __pfn_to_section(pfn)->pageblock_flags; + return section_to_usemap(__pfn_to_section(pfn)); #else return page_zone(page)->pageblock_flags; #endif /* CONFIG_SPARSEMEM */ diff --git a/mm/sparse.c b/mm/sparse.c index fd13166949b5..f87de7ad32c8 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -288,33 +288,31 @@ struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pn static void __meminit sparse_init_one_section(struct mem_section *ms, unsigned long pnum, struct page *mem_map, - unsigned long *pageblock_bitmap) + struct mem_section_usage *usage) { ms->section_mem_map &= ~SECTION_MAP_MASK; ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum) | SECTION_HAS_MEM_MAP; - ms->pageblock_flags = pageblock_bitmap; + ms->usage = usage; } -unsigned long usemap_size(void) +static unsigned long usemap_size(void) { return BITS_TO_LONGS(SECTION_BLOCKFLAGS_BITS) * sizeof(unsigned long); } -#ifdef CONFIG_MEMORY_HOTPLUG -static unsigned long *__kmalloc_section_usemap(void) +size_t mem_section_usage_size(void) { - return kmalloc(usemap_size(), GFP_KERNEL); + return sizeof(struct mem_section_usage) + usemap_size(); } -#endif /* CONFIG_MEMORY_HOTPLUG */ #ifdef CONFIG_MEMORY_HOTREMOVE -static unsigned long * __init +static struct mem_section_usage * __init sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat, unsigned long size) { + struct mem_section_usage *usage; unsigned long goal, limit; - unsigned long *p; int nid; /* * A page may contain usemaps for other sections preventing the @@ -330,15 +328,16 @@ sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat, limit = goal + (1UL << PA_SECTION_SHIFT); nid = early_pfn_to_nid(goal >> PAGE_SHIFT); again: - p = memblock_alloc_try_nid(size, SMP_CACHE_BYTES, goal, limit, nid); - if (!p && limit) { + usage = memblock_alloc_try_nid(size, SMP_CACHE_BYTES, goal, limit, nid); + if (!usage && limit) { limit = 0; goto again; } - return p; + return usage; } -static void __init check_usemap_section_nr(int nid, unsigned long *usemap) +static void __init check_usemap_section_nr(int nid, + struct mem_section_usage *usage) { unsigned long usemap_snr, pgdat_snr; static unsigned long old_usemap_snr; @@ -352,7 +351,7 @@ static void __init check_usemap_section_nr(int nid, unsigned long *usemap) old_pgdat_snr = NR_MEM_SECTIONS; } - usemap_snr = pfn_to_section_nr(__pa(usemap) >> PAGE_SHIFT); + usemap_snr = pfn_to_section_nr(__pa(usage) >> PAGE_SHIFT); pgdat_snr = pfn_to_section_nr(__pa(pgdat) >> PAGE_SHIFT); if (usemap_snr == pgdat_snr) return; @@ -380,14 +379,15 @@ static void __init check_usemap_section_nr(int nid, unsigned long *usemap) usemap_snr, pgdat_snr, nid); } #else -static unsigned long * __init +static struct mem_section_usage * __init sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat, unsigned long size) { return memblock_alloc_node(size, SMP_CACHE_BYTES, pgdat->node_id); } -static void __init check_usemap_section_nr(int nid, unsigned long *usemap) +static void __init check_usemap_section_nr(int nid, + struct mem_section_usage *usage) { } #endif /* CONFIG_MEMORY_HOTREMOVE */ @@ -474,14 +474,13 @@ static void __init sparse_init_nid(int nid, unsigned long pnum_begin, unsigned long pnum_end, unsigned long map_count) { - unsigned long pnum, usemap_longs, *usemap; + struct mem_section_usage *usage; + unsigned long pnum; struct page *map; - usemap_longs = BITS_TO_LONGS(SECTION_BLOCKFLAGS_BITS); - usemap = sparse_early_usemaps_alloc_pgdat_section(NODE_DATA(nid), - usemap_size() * - map_count); - if (!usemap) { + usage = sparse_early_usemaps_alloc_pgdat_section(NODE_DATA(nid), + mem_section_usage_size() * map_count); + if (!usage) { pr_err("%s: node[%d] usemap allocation failed", __func__, nid); goto failed; } @@ -497,9 +496,9 @@ static void __init sparse_init_nid(int nid, unsigned long pnum_begin, pnum_begin = pnum; goto failed; } - check_usemap_section_nr(nid, usemap); - sparse_init_one_section(__nr_to_section(pnum), pnum, map, usemap); - usemap += usemap_longs; + check_usemap_section_nr(nid, usage); + sparse_init_one_section(__nr_to_section(pnum), pnum, map, usage); + usage = (void *) usage + mem_section_usage_size(); } sparse_buffer_fini(); return; @@ -701,9 +700,9 @@ int __meminit sparse_add_one_section(int nid, unsigned long start_pfn, struct vmem_altmap *altmap) { unsigned long section_nr = pfn_to_section_nr(start_pfn); + struct mem_section_usage *usage; struct mem_section *ms; struct page *memmap; - unsigned long *usemap; int ret; /* @@ -717,8 +716,8 @@ int __meminit sparse_add_one_section(int nid, unsigned long start_pfn, memmap = kmalloc_section_memmap(section_nr, nid, altmap); if (!memmap) return -ENOMEM; - usemap = __kmalloc_section_usemap(); - if (!usemap) { + usage = kzalloc(mem_section_usage_size(), GFP_KERNEL); + if (!usage) { __kfree_section_memmap(memmap, altmap); return -ENOMEM; } @@ -736,11 +735,11 @@ int __meminit sparse_add_one_section(int nid, unsigned long start_pfn, page_init_poison(memmap, sizeof(struct page) * PAGES_PER_SECTION); section_mark_present(ms); - sparse_init_one_section(ms, section_nr, memmap, usemap); + sparse_init_one_section(ms, section_nr, memmap, usage); out: if (ret < 0) { - kfree(usemap); + kfree(usage); __kfree_section_memmap(memmap, altmap); } return ret; @@ -777,20 +776,20 @@ static inline void clear_hwpoisoned_pages(struct page *memmap, int nr_pages) } #endif -static void free_section_usemap(struct page *memmap, unsigned long *usemap, - struct vmem_altmap *altmap) +static void free_section_usage(struct page *memmap, + struct mem_section_usage *usage, struct vmem_altmap *altmap) { - struct page *usemap_page; + struct page *usage_page; - if (!usemap) + if (!usage) return; - usemap_page = virt_to_page(usemap); + usage_page = virt_to_page(usage); /* * Check to see if allocation came from hot-plug-add */ - if (PageSlab(usemap_page) || PageCompound(usemap_page)) { - kfree(usemap); + if (PageSlab(usage_page) || PageCompound(usage_page)) { + kfree(usage); if (memmap) __kfree_section_memmap(memmap, altmap); return; @@ -809,19 +808,19 @@ void sparse_remove_one_section(struct zone *zone, struct mem_section *ms, unsigned long map_offset, struct vmem_altmap *altmap) { struct page *memmap = NULL; - unsigned long *usemap = NULL; + struct mem_section_usage *usage = NULL; if (ms->section_mem_map) { - usemap = ms->pageblock_flags; + usage = ms->usage; memmap = sparse_decode_mem_map(ms->section_mem_map, __section_nr(ms)); ms->section_mem_map = 0; - ms->pageblock_flags = NULL; + ms->usage = NULL; } clear_hwpoisoned_pages(memmap + map_offset, PAGES_PER_SECTION - map_offset); - free_section_usemap(memmap, usemap, altmap); + free_section_usage(memmap, usage, altmap); } #endif /* CONFIG_MEMORY_HOTREMOVE */ #endif /* CONFIG_MEMORY_HOTPLUG */