From: David Hildenbrand <david@xxxxxxxxxx> Subject: mm/page_alloc: simplify __offline_isolated_pages() offline_pages() is the only user. __offline_isolated_pages() never gets called with ranges that contain memory holes and we no longer care about the return value. Drop the return value handling and all pfn_valid() checks. Update the documentation. Link: https://lkml.kernel.org/r/20200819175957.28465-5-david@xxxxxxxxxx Signed-off-by: David Hildenbrand <david@xxxxxxxxxx> Acked-by: Michal Hocko <mhocko@xxxxxxxx> Reviewed-by: Oscar Salvador <osalvador@xxxxxxx> Cc: Wei Yang <richard.weiyang@xxxxxxxxxxxxxxxxx> Cc: Baoquan He <bhe@xxxxxxxxxx> Cc: Pankaj Gupta <pankaj.gupta.linux@xxxxxxxxx> Cc: Charan Teja Reddy <charante@xxxxxxxxxxxxxx> Cc: Dan Williams <dan.j.williams@xxxxxxxxx> Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx> Cc: Logan Gunthorpe <logang@xxxxxxxxxxxx> Cc: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> Cc: Mel Gorman <mgorman@xxxxxxx> Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> Cc: Michel Lespinasse <walken@xxxxxxxxxx> Cc: Mike Rapoport <rppt@xxxxxxxxxx> Cc: Tony Luck <tony.luck@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/memory_hotplug.h | 4 ++-- mm/page_alloc.c | 27 ++++----------------------- 2 files changed, 6 insertions(+), 25 deletions(-) --- a/include/linux/memory_hotplug.h~mm-page_alloc-simplify-__offline_isolated_pages +++ a/include/linux/memory_hotplug.h @@ -103,8 +103,8 @@ extern int online_pages(unsigned long pf int online_type, int nid); extern struct zone *test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn); -extern unsigned long __offline_isolated_pages(unsigned long start_pfn, - unsigned long end_pfn); +extern void __offline_isolated_pages(unsigned long start_pfn, + unsigned long end_pfn); typedef void (*online_page_callback_t)(struct page *page, unsigned int order); --- a/mm/page_alloc.c~mm-page_alloc-simplify-__offline_isolated_pages +++ a/mm/page_alloc.c @@ -8704,35 +8704,21 @@ void zone_pcp_reset(struct zone *zone) #ifdef CONFIG_MEMORY_HOTREMOVE /* - * All pages in the range must be in a single zone and isolated - * before calling this. + * All pages in the range must be in a single zone, must not contain holes, + * must span full sections, and must be isolated before calling this function. */ -unsigned long -__offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn) +void __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn) { + unsigned long pfn = start_pfn; struct page *page; struct zone *zone; unsigned int order; - unsigned long pfn; unsigned long flags; - unsigned long offlined_pages = 0; - - /* find the first valid pfn */ - for (pfn = start_pfn; pfn < end_pfn; pfn++) - if (pfn_valid(pfn)) - break; - if (pfn == end_pfn) - return offlined_pages; offline_mem_sections(pfn, end_pfn); zone = page_zone(pfn_to_page(pfn)); spin_lock_irqsave(&zone->lock, flags); - pfn = start_pfn; while (pfn < end_pfn) { - if (!pfn_valid(pfn)) { - pfn++; - continue; - } page = pfn_to_page(pfn); /* * The HWPoisoned page may be not in buddy system, and @@ -8740,7 +8726,6 @@ __offline_isolated_pages(unsigned long s */ if (unlikely(!PageBuddy(page) && PageHWPoison(page))) { pfn++; - offlined_pages++; continue; } /* @@ -8751,20 +8736,16 @@ __offline_isolated_pages(unsigned long s BUG_ON(page_count(page)); BUG_ON(PageBuddy(page)); pfn++; - offlined_pages++; continue; } BUG_ON(page_count(page)); BUG_ON(!PageBuddy(page)); order = page_order(page); - offlined_pages += 1 << order; del_page_from_free_list(page, zone, order); pfn += (1 << order); } spin_unlock_irqrestore(&zone->lock, flags); - - return offlined_pages; } #endif _
