powerpc: get rid of superfluous __GFP_REPEAT

__GFP_REPEAT has a rather weak semantic but since it has been introduced
around 2.6.12 it has been ignored for low order allocations.

{pud,pmd}_alloc_one are allocating from {PGT,PUD}_CACHE initialized in
pgtable_cache_init which doesn't have larger than sizeof(void *) << 12
size and that fits into !costly allocation request size.

PGALLOC_GFP is used only in radix__pgd_alloc which uses either order-0
or order-4 requests.  The first one doesn't need the flag while the
second does.  Drop __GFP_REPEAT from PGALLOC_GFP and add it for the
order-4 one.

This means that this flag has never been actually useful here because it
has always been used only for PAGE_ALLOC_COSTLY requests.

Link: http://lkml.kernel.org/r/1464599699-30131-12-git-send-email-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/powerpc/include/asm/nohash/64/pgalloc.h

@@ -57,8 +57,7 @@ static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
 
 static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr)
 {
-	return kmem_cache_alloc(PGT_CACHE(PUD_INDEX_SIZE),
-				GFP_KERNEL|__GFP_REPEAT);
+	return kmem_cache_alloc(PGT_CACHE(PUD_INDEX_SIZE), GFP_KERNEL);
 }
 
 static inline void pud_free(struct mm_struct *mm, pud_t *pud)
@@ -190,8 +189,7 @@ static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t table,
 
 static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
 {
-	return kmem_cache_alloc(PGT_CACHE(PMD_CACHE_INDEX),
-				GFP_KERNEL|__GFP_REPEAT);
+	return kmem_cache_alloc(PGT_CACHE(PMD_CACHE_INDEX), GFP_KERNEL);
 }
 
 static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)