mm/memory_hotplug: drop valid_start/valid_end from test_pages_in_a_zone()

The callers are only interested in the actual zone, they don't care about
boundaries.  Return the zone instead to simplify.

Link: http://lkml.kernel.org/r/20200110183308.11849-1-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 15659306ad695432828164e24a62998f1ea1c038..b9f474c1139302116c9639612ea7746e7427b4f1 100644 (file)
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -376,7 +376,6 @@ static ssize_t valid_zones_show(struct device *dev,
        struct memory_block *mem = to_memory_block(dev);
        unsigned long start_pfn = section_nr_to_pfn(mem->start_section_nr);
        unsigned long nr_pages = PAGES_PER_SECTION * sections_per_block;
-       unsigned long valid_start_pfn, valid_end_pfn;
        struct zone *default_zone;
        int nid;
 
@@ -389,11 +388,11 @@ static ssize_t valid_zones_show(struct device *dev,
                 * The block contains more than one zone can not be offlined.
                 * This can happen e.g. for ZONE_DMA and ZONE_DMA32
                 */
-               if (!test_pages_in_a_zone(start_pfn, start_pfn + nr_pages,
-                                         &valid_start_pfn, &valid_end_pfn))
+               default_zone = test_pages_in_a_zone(start_pfn,
+                                                   start_pfn + nr_pages);
+               if (!default_zone)
                        return sprintf(buf, "none\n");
-               start_pfn = valid_start_pfn;
-               strcat(buf, page_zone(pfn_to_page(start_pfn))->name);
+               strcat(buf, default_zone->name);
                goto out;
        }
 

diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
index ffa6ad12d84a69bb68fa5d7c2783a1ad44e506f7..f4d59155f3d47a093067b5fd32eeff3c1b48c06a 100644 (file)
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -96,8 +96,8 @@ extern int add_one_highpage(struct page *page, int pfn, int bad_ppro);
 /* VM interface that may be used by firmware interface */
 extern int online_pages(unsigned long pfn, unsigned long nr_pages,
                        int online_type, int nid);
-extern int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn,
-       unsigned long *valid_start, unsigned long *valid_end);
+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);
 

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 4344e85213f2567311f77833a69fb782272efbdf..0a54ffac8c682ae5c940642c6b5d45cfb22cada5 100644 (file)
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1172,14 +1172,13 @@ bool is_mem_section_removable(unsigned long start_pfn, unsigned long nr_pages)
 }
 
 /*
- * Confirm all pages in a range [start, end) belong to the same zone.
- * When true, return its valid [start, end).
+ * Confirm all pages in a range [start, end) belong to the same zone (skipping
+ * memory holes). When true, return the zone.
  */
-int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn,
-                        unsigned long *valid_start, unsigned long *valid_end)
+struct zone *test_pages_in_a_zone(unsigned long start_pfn,
+                                 unsigned long end_pfn)
 {
        unsigned long pfn, sec_end_pfn;
-       unsigned long start, end;
        struct zone *zone = NULL;
        struct page *page;
        int i;
@@ -1200,24 +1199,15 @@ int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn,
                                continue;
                        /* Check if we got outside of the zone */
                        if (zone && !zone_spans_pfn(zone, pfn + i))
-                               return 0;
+                               return NULL;
                        page = pfn_to_page(pfn + i);
                        if (zone && page_zone(page) != zone)
-                               return 0;
-                       if (!zone)
-                               start = pfn + i;
+                               return NULL;
                        zone = page_zone(page);
-                       end = pfn + MAX_ORDER_NR_PAGES;
                }
        }
 
-       if (zone) {
-               *valid_start = start;
-               *valid_end = min(end, end_pfn);
-               return 1;
-       } else {
-               return 0;
-       }
+       return zone;
 }
 
 /*
@@ -1462,7 +1452,6 @@ static int __ref __offline_pages(unsigned long start_pfn,
        unsigned long offlined_pages = 0;
        int ret, node, nr_isolate_pageblock;
        unsigned long flags;
-       unsigned long valid_start, valid_end;
        struct zone *zone;
        struct memory_notify arg;
        char *reason;
@@ -1487,14 +1476,12 @@ static int __ref __offline_pages(unsigned long start_pfn,
 
        /* This makes hotplug much easier...and readable.
           we assume this for now. .*/
-       if (!test_pages_in_a_zone(start_pfn, end_pfn, &valid_start,
-                                 &valid_end)) {
+       zone = test_pages_in_a_zone(start_pfn, end_pfn);
+       if (!zone) {
                ret = -EINVAL;
                reason = "multizone range";
                goto failed_removal;
        }
-
-       zone = page_zone(pfn_to_page(valid_start));
        node = zone_to_nid(zone);
 
        /* set above range as isolated */