mm/page_isolation: simplify return value of start_isolate_page_range()

Callers no longer need the number of isolated pageblocks.  Let's simplify.

Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Michal Hocko <mhocko@suse.com>
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>
Link: https://lkml.kernel.org/r/20200819175957.28465-7-david@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 9052444..d61e5be 100644 (file)
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1514,7 +1514,7 @@ int __ref offline_pages(unsigned long start_pfn, unsigned long nr_pages)
        ret = start_isolate_page_range(start_pfn, end_pfn,
                                       MIGRATE_MOVABLE,
                                       MEMORY_OFFLINE | REPORT_FAILURE);
-       if (ret < 0) {
+       if (ret) {
                reason = "failure to isolate range";
                goto failed_removal;
        }

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index acc04ca..19807b6 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -8468,7 +8468,7 @@ int alloc_contig_range(unsigned long start, unsigned long end,
 
        ret = start_isolate_page_range(pfn_max_align_down(start),
                                       pfn_max_align_up(end), migratetype, 0);
-       if (ret < 0)
+       if (ret)
                return ret;
 
        /*

diff --git a/mm/page_isolation.c b/mm/page_isolation.c
index aa94afb..abfe26a 100644 (file)
--- a/mm/page_isolation.c
+++ b/mm/page_isolation.c
@@ -173,8 +173,7 @@ __first_valid_page(unsigned long pfn, unsigned long nr_pages)
  * (e.g. __offline_pages will need to call it after check for isolated range for
  * a next retry).
  *
- * Return: the number of isolated pageblocks on success and -EBUSY if any part
- * of range cannot be isolated.
+ * Return: 0 on success and -EBUSY if any part of range cannot be isolated.
  */
 int start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn,
                             unsigned migratetype, int flags)
@@ -182,7 +181,6 @@ int start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn,
        unsigned long pfn;
        unsigned long undo_pfn;
        struct page *page;
-       int nr_isolate_pageblock = 0;
 
        BUG_ON(!IS_ALIGNED(start_pfn, pageblock_nr_pages));
        BUG_ON(!IS_ALIGNED(end_pfn, pageblock_nr_pages));
@@ -196,10 +194,9 @@ int start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn,
                                undo_pfn = pfn;
                                goto undo;
                        }
-                       nr_isolate_pageblock++;
                }
        }
-       return nr_isolate_pageblock;
+       return 0;
 undo:
        for (pfn = start_pfn;
             pfn < undo_pfn;