[PATCH 2/2] mm: Create non-atomic version of SetPageReserved for init use

[Alexander Duyck]

From: Alexander Duyck <alexander.h.du...@intel.com>

It doesn't make much sense to use the atomic SetPageReserved at init time
when we are using memset to clear the memory and manipulating the page
flags via simple "&=" and "|=" operations in __init_single_page.

This patch adds a non-atomic version __SetPageReserved that can be used
during page init and shows about a 10% improvement in initialization times
on the systems I have available for testing.

Signed-off-by: Alexander Duyck <alexander.h.du...@intel.com>
---
 include/linux/page-flags.h |    1 +
 mm/page_alloc.c            |    4 ++--
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 74bee8cecf4c..57ec3fef7e9f 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -292,6 +292,7 @@ static inline int PagePoisoned(const struct page *page)
 
 PAGEFLAG(Reserved, reserved, PF_NO_COMPOUND)
        __CLEARPAGEFLAG(Reserved, reserved, PF_NO_COMPOUND)
+       __SETPAGEFLAG(Reserved, reserved, PF_NO_COMPOUND)
 PAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL)
        __CLEARPAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL)
        __SETPAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 05e983f42316..9c7d6e971630 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1231,7 +1231,7 @@ void __meminit reserve_bootmem_region(phys_addr_t start, 
phys_addr_t end)
                        /* Avoid false-positive PageTail() */
                        INIT_LIST_HEAD(&page->lru);
 
-                       SetPageReserved(page);
+                       __SetPageReserved(page);
                }
        }
 }
@@ -5518,7 +5518,7 @@ void __meminit memmap_init_zone(unsigned long size, int 
nid, unsigned long zone,
                page = pfn_to_page(pfn);
                __init_single_page(page, pfn, zone, nid);
                if (context == MEMMAP_HOTPLUG)
-                       SetPageReserved(page);
+                       __SetPageReserved(page);
 
                /*
                 * Mark the block movable so that blocks are reserved for