From 49ba3c6b37b38b58251c27864f551908c583e99d Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Thu, 18 Jul 2019 15:58:07 -0700 Subject: [PATCH] mm/hotplug: prepare shrink_{zone, pgdat}_span for sub-section removal MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Sub-section hotplug support reduces the unit of operation of hotplug from section-sized-units (PAGES_PER_SECTION) to sub-section-sized units (PAGES_PER_SUBSECTION). Teach shrink_{zone,pgdat}_span() to consider PAGES_PER_SUBSECTION boundaries as the points where pfn_valid(), not valid_section(), can toggle. [osalvador@suse.de: fix shrink_{zone,node}_span] Link: http://lkml.kernel.org/r/20190717090725.23618-3-osalvador@suse.de Link: http://lkml.kernel.org/r/156092351496.979959.12703722803097017492.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams Signed-off-by: Oscar Salvador Reviewed-by: Pavel Tatashin Reviewed-by: Oscar Salvador Tested-by: Aneesh Kumar K.V [ppc64] Cc: Michal Hocko Cc: Vlastimil Babka Cc: Logan Gunthorpe Cc: David Hildenbrand Cc: Jane Chu Cc: Jeff Moyer Cc: Jérôme Glisse Cc: Jonathan Corbet Cc: Mike Rapoport Cc: Toshi Kani Cc: Wei Yang Cc: Jason Gunthorpe Cc: Christoph Hellwig Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memory_hotplug.c | 37 ++++++++++++------------------------- 1 file changed, 12 insertions(+), 25 deletions(-) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index cf9d979a6498..85467914ad23 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -318,12 +318,8 @@ static unsigned long find_smallest_section_pfn(int nid, struct zone *zone, unsigned long start_pfn, unsigned long end_pfn) { - struct mem_section *ms; - - for (; start_pfn < end_pfn; start_pfn += PAGES_PER_SECTION) { - ms = __pfn_to_section(start_pfn); - - if (unlikely(!valid_section(ms))) + for (; start_pfn < end_pfn; start_pfn += PAGES_PER_SUBSECTION) { + if (unlikely(!pfn_valid(start_pfn))) continue; if (unlikely(pfn_to_nid(start_pfn) != nid)) @@ -343,15 +339,12 @@ static unsigned long find_biggest_section_pfn(int nid, struct zone *zone, unsigned long start_pfn, unsigned long end_pfn) { - struct mem_section *ms; unsigned long pfn; /* pfn is the end pfn of a memory section. */ pfn = end_pfn - 1; - for (; pfn >= start_pfn; pfn -= PAGES_PER_SECTION) { - ms = __pfn_to_section(pfn); - - if (unlikely(!valid_section(ms))) + for (; pfn >= start_pfn; pfn -= PAGES_PER_SUBSECTION) { + if (unlikely(!pfn_valid(pfn))) continue; if (unlikely(pfn_to_nid(pfn) != nid)) @@ -373,7 +366,6 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn, unsigned long z = zone_end_pfn(zone); /* zone_end_pfn namespace clash */ unsigned long zone_end_pfn = z; unsigned long pfn; - struct mem_section *ms; int nid = zone_to_nid(zone); zone_span_writelock(zone); @@ -410,17 +402,15 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn, * it check the zone has only hole or not. */ pfn = zone_start_pfn; - for (; pfn < zone_end_pfn; pfn += PAGES_PER_SECTION) { - ms = __pfn_to_section(pfn); - - if (unlikely(!valid_section(ms))) + for (; pfn < zone_end_pfn; pfn += PAGES_PER_SUBSECTION) { + if (unlikely(!pfn_valid(pfn))) continue; if (page_zone(pfn_to_page(pfn)) != zone) continue; - /* If the section is current section, it continues the loop */ - if (start_pfn == pfn) + /* Skip range to be removed */ + if (pfn >= start_pfn && pfn < end_pfn) continue; /* If we find valid section, we have nothing to do */ @@ -441,7 +431,6 @@ static void shrink_pgdat_span(struct pglist_data *pgdat, unsigned long p = pgdat_end_pfn(pgdat); /* pgdat_end_pfn namespace clash */ unsigned long pgdat_end_pfn = p; unsigned long pfn; - struct mem_section *ms; int nid = pgdat->node_id; if (pgdat_start_pfn == start_pfn) { @@ -478,17 +467,15 @@ static void shrink_pgdat_span(struct pglist_data *pgdat, * has only hole or not. */ pfn = pgdat_start_pfn; - for (; pfn < pgdat_end_pfn; pfn += PAGES_PER_SECTION) { - ms = __pfn_to_section(pfn); - - if (unlikely(!valid_section(ms))) + for (; pfn < pgdat_end_pfn; pfn += PAGES_PER_SUBSECTION) { + if (unlikely(!pfn_valid(pfn))) continue; if (pfn_to_nid(pfn) != nid) continue; - /* If the section is current section, it continues the loop */ - if (start_pfn == pfn) + /* Skip range to be removed */ + if (pfn >= start_pfn && pfn < end_pfn) continue; /* If we find valid section, we have nothing to do */ -- 2.30.2