diff mbox series

[063/156] mm/memory_hotplug: drop nr_isolate_pageblock in offline_pages()

Message ID 20201016024453.UOTCP0gPH%akpm@linux-foundation.org
State New
Headers show
Series [001/156] device-dax/kmem: fix resource release | expand

Commit Message

Andrew Morton Oct. 16, 2020, 2:44 a.m. UTC
From: David Hildenbrand <david@redhat.com>
Subject: mm/memory_hotplug: drop nr_isolate_pageblock in offline_pages()

We make sure that we cannot have any memory holes right at the beginning
of offline_pages() and we only support to online/offline full sections. 
Both, sections and pageblocks are a power of two in size, and sections
always span full pageblocks.

We can directly calculate the number of isolated pageblocks from nr_pages.

Link: https://lkml.kernel.org/r/20200819175957.28465-6-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Charan Teja Reddy <charante@codeaurora.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michel Lespinasse <walken@google.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

 mm/memory_hotplug.c |    5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)
diff mbox series


--- a/mm/memory_hotplug.c~mm-memory_hotplug-drop-nr_isolate_pageblock-in-offline_pages
+++ a/mm/memory_hotplug.c
@@ -1471,10 +1471,10 @@  int __ref offline_pages(unsigned long st
 	const unsigned long end_pfn = start_pfn + nr_pages;
 	unsigned long pfn, system_ram_pages = 0;
-	int ret, node, nr_isolate_pageblock;
 	unsigned long flags;
 	struct zone *zone;
 	struct memory_notify arg;
+	int ret, node;
 	char *reason;
 	/* We can only offline full sections (e.g., SECTION_IS_ONLINE) */
@@ -1518,7 +1518,6 @@  int __ref offline_pages(unsigned long st
 		reason = "failure to isolate range";
 		goto failed_removal;
-	nr_isolate_pageblock = ret;
 	arg.start_pfn = start_pfn;
 	arg.nr_pages = nr_pages;
@@ -1596,7 +1595,7 @@  int __ref offline_pages(unsigned long st
 	 * pageblocks zone counter here.
 	spin_lock_irqsave(&zone->lock, flags);
-	zone->nr_isolate_pageblock -= nr_isolate_pageblock;
+	zone->nr_isolate_pageblock -= nr_pages / pageblock_nr_pages;
 	spin_unlock_irqrestore(&zone->lock, flags);
 	/* removal success */