Since we always populate low zones, it is not necessary to count nr_initialised for them. Let's move the last zone check ahead to skip the nr_initialised reset. Assume low zones counts for 4G, this change may reduce 1M times comparison of prev_end_pfn and end_pfn. Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxx> --- mm/mm_init.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/mm/mm_init.c b/mm/mm_init.c index 2dfb87841fdb..4cc627b4ebfe 100644 --- a/mm/mm_init.c +++ b/mm/mm_init.c @@ -676,6 +676,11 @@ defer_init(int nid, unsigned long pfn, unsigned long end_pfn) if (early_page_ext_enabled()) return false; + + /* Always populate low zones for address-constrained allocations */ + if (end_pfn < pgdat_end_pfn(NODE_DATA(nid))) + return false; + /* * prev_end_pfn static that contains the end of previous zone * No need to protect because called very early in boot before smp_init. @@ -685,10 +690,6 @@ defer_init(int nid, unsigned long pfn, unsigned long end_pfn) nr_initialised = 0; } - /* Always populate low zones for address-constrained allocations */ - if (end_pfn < pgdat_end_pfn(NODE_DATA(nid))) - return false; - if (NODE_DATA(nid)->first_deferred_pfn != ULONG_MAX) return true; /* -- 2.34.1
