mm, page_ext: periodically reschedule during page_ext_init()

page_ext_init() can take long on large machines, so add a cond_resched()
point after each section is processed.  This will allow moving the init
to a later point at boot without triggering lockup reports.

Link: http://lkml.kernel.org/r/20170720134029.25268-3-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Yang Shi <yang.shi@linaro.org>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Vinayak Menon <vinmenon@codeaurora.org>
Cc: zhong jiang <zhongjiang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/page_ext.c b/mm/page_ext.c
index 714ce79..32f1891 100644 (file)
--- a/mm/page_ext.c
+++ b/mm/page_ext.c
@@ -406,6 +406,7 @@ void __init page_ext_init(void)
                                continue;
                        if (init_section_page_ext(pfn, nid))
                                goto oom;
+                       cond_resched();
                }
        }
        hotplug_memory_notifier(page_ext_callback, 0);