mm, memcg: sync allocation and memcg charge gfp flags for thp fix fix

"mm, memcg: sync allocation and memcg charge gfp flags for THP" in -mm
introduces a formal to pass the gfp mask for khugepaged's hugepage
allocation.  This is just too ugly to live.

alloc_hugepage_gfpmask() cannot differ between NUMA and UMA configs by
anything in GFP_RECLAIM_MASK, which is the only thing that matters for
memcg reclaim, so just determine the gfp flags once in
collapse_huge_page() and avoid the complexity.

Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 00be5cb9af6d905894dc88b7c1b9ee15b6be2e83..b6e55143f19dab5ad0b8d615307bf33c7257a52e 100644 (file)
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2322,16 +2322,12 @@ static bool khugepaged_prealloc_page(struct page **hpage, bool *wait)
 }
 
 static struct page *
-khugepaged_alloc_page(struct page **hpage, gfp_t *gfp, struct mm_struct *mm,
+khugepaged_alloc_page(struct page **hpage, gfp_t gfp, struct mm_struct *mm,
                       struct vm_area_struct *vma, unsigned long address,
                       int node)
 {
        VM_BUG_ON_PAGE(*hpage, *hpage);
 
-       /* Only allocate from the target node */
-       *gfp = alloc_hugepage_gfpmask(khugepaged_defrag(), __GFP_OTHER_NODE) |
-               __GFP_THISNODE;
-
        /*
         * Before allocating the hugepage, release the mmap_sem read lock.
         * The allocation can take potentially a long time if it involves
@@ -2340,7 +2336,7 @@ khugepaged_alloc_page(struct page **hpage, gfp_t *gfp, struct mm_struct *mm,
         */
        up_read(&mm->mmap_sem);
 
-       *hpage = alloc_pages_exact_node(node, *gfp, HPAGE_PMD_ORDER);
+       *hpage = alloc_pages_exact_node(node, gfp, HPAGE_PMD_ORDER);
        if (unlikely(!*hpage)) {
                count_vm_event(THP_COLLAPSE_ALLOC_FAILED);
                *hpage = ERR_PTR(-ENOMEM);
@@ -2394,18 +2390,13 @@ static bool khugepaged_prealloc_page(struct page **hpage, bool *wait)
 }
 
 static struct page *
-khugepaged_alloc_page(struct page **hpage, gfp_t *gfp, struct mm_struct *mm,
+khugepaged_alloc_page(struct page **hpage, gfp_t gfp, struct mm_struct *mm,
                       struct vm_area_struct *vma, unsigned long address,
                       int node)
 {
        up_read(&mm->mmap_sem);
        VM_BUG_ON(!*hpage);
 
-       /*
-        * khugepaged_alloc_hugepage is doing the preallocation, use the same
-        * gfp flags here.
-        */
-       *gfp = alloc_hugepage_gfpmask(khugepaged_defrag(), 0);
        return  *hpage;
 }
 #endif
@@ -2444,8 +2435,12 @@ static void collapse_huge_page(struct mm_struct *mm,
 
        VM_BUG_ON(address & ~HPAGE_PMD_MASK);
 
+       /* Only allocate from the target node */
+       gfp = alloc_hugepage_gfpmask(khugepaged_defrag(), __GFP_OTHER_NODE) |
+               __GFP_THISNODE;
+
        /* release the mmap_sem read lock. */
-       new_page = khugepaged_alloc_page(hpage, &gfp, mm, vma, address, node);
+       new_page = khugepaged_alloc_page(hpage, gfp, mm, vma, address, node);
        if (!new_page)
                return;