From: David Hildenbrand <david@xxxxxxxxxx> Subject: mm/memory_hotplug: cleanup __remove_pages() Let's drop the basically unused section stuff and simplify. Also, let's use a shorter variant to calculate the number of pages to the next section boundary. Link: http://lkml.kernel.org/r/20191006085646.5768-11-david@xxxxxxxxxx Signed-off-by: David Hildenbrand <david@xxxxxxxxxx> Cc: Oscar Salvador <osalvador@xxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxx> Cc: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> Cc: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxx> Cc: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: Dan Williams <dan.j.williams@xxxxxxxxx> Cc: Logan Gunthorpe <logang@xxxxxxxxxxxx> Cc: Pankaj Gupta <pagupta@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/memory_hotplug.c | 17 ++++++----------- 1 file changed, 6 insertions(+), 11 deletions(-) --- a/mm/memory_hotplug.c~mm-memory_hotplug-cleanup-__remove_pages +++ a/mm/memory_hotplug.c @@ -516,25 +516,20 @@ static void __remove_section(unsigned lo void __remove_pages(unsigned long pfn, unsigned long nr_pages, struct vmem_altmap *altmap) { + const unsigned long end_pfn = pfn + nr_pages; + unsigned long cur_nr_pages; unsigned long map_offset = 0; - unsigned long nr, start_sec, end_sec; map_offset = vmem_altmap_offset(altmap); if (check_pfn_span(pfn, nr_pages, "remove")) return; - start_sec = pfn_to_section_nr(pfn); - end_sec = pfn_to_section_nr(pfn + nr_pages - 1); - for (nr = start_sec; nr <= end_sec; nr++) { - unsigned long pfns; - + for (; pfn < end_pfn; pfn += cur_nr_pages) { cond_resched(); - pfns = min(nr_pages, PAGES_PER_SECTION - - (pfn & ~PAGE_SECTION_MASK)); - __remove_section(pfn, pfns, map_offset, altmap); - pfn += pfns; - nr_pages -= pfns; + /* Select all remaining pages up to the next section boundary */ + cur_nr_pages = min(end_pfn - pfn, -(pfn | PAGE_SECTION_MASK)); + __remove_section(pfn, cur_nr_pages, map_offset, altmap); map_offset = 0; } } _
