thp: add numa awareness to hugepage allocations

It's mostly a matter of replacing alloc_pages with alloc_pages_vma after
introducing alloc_pages_vma.  khugepaged needs special handling as the
allocation has to happen inside collapse_huge_page where the vma is known
and an error has to be returned to the outer loop to sleep
alloc_sleep_millisecs in case of failure.  But it retains the more
efficient logic of handling allocation failures in khugepaged in case of
CONFIG_NUMA=n.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 74 insertions, 13 deletions

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 0415a83afd66..f6559e7711bd 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -620,11 +620,26 @@ static int __do_huge_pmd_anonymous_page(struct mm_struct *mm,
         return ret;
 }
 
+static inline gfp_t alloc_hugepage_gfpmask(int defrag)
+{
+        return GFP_TRANSHUGE & ~(defrag ? 0 : __GFP_WAIT);
+}
+
+static inline struct page *alloc_hugepage_vma(int defrag,
+                                              struct vm_area_struct *vma,
+                                              unsigned long haddr)
+{
+        return alloc_pages_vma(alloc_hugepage_gfpmask(defrag),
+                               HPAGE_PMD_ORDER, vma, haddr);
+}
+
+#ifndef CONFIG_NUMA
 static inline struct page *alloc_hugepage(int defrag)
 {
-        return alloc_pages(GFP_TRANSHUGE & ~(defrag ? 0 : __GFP_WAIT),
+        return alloc_pages(alloc_hugepage_gfpmask(defrag),
                            HPAGE_PMD_ORDER);
 }
+#endif
 
 int do_huge_pmd_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
                                unsigned long address, pmd_t *pmd,
@@ -639,7 +654,8 @@ int do_huge_pmd_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
                         return VM_FAULT_OOM;
                 if (unlikely(khugepaged_enter(vma)))
                         return VM_FAULT_OOM;
-                page = alloc_hugepage(transparent_hugepage_defrag(vma));
+                page = alloc_hugepage_vma(transparent_hugepage_defrag(vma),
+                                          vma, haddr);
                 if (unlikely(!page))
                         goto out;
                 if (unlikely(mem_cgroup_newpage_charge(page, mm, GFP_KERNEL))) {
@@ -862,7 +878,8 @@ int do_huge_pmd_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
 
         if (transparent_hugepage_enabled(vma) &&
             !transparent_hugepage_debug_cow())
-                new_page = alloc_hugepage(transparent_hugepage_defrag(vma));
+                new_page = alloc_hugepage_vma(transparent_hugepage_defrag(vma),
+                                              vma, haddr);
         else
                 new_page = NULL;
 
@@ -1661,7 +1678,11 @@ static void collapse_huge_page(struct mm_struct *mm,
         unsigned long hstart, hend;
 
         VM_BUG_ON(address & ~HPAGE_PMD_MASK);
+#ifndef CONFIG_NUMA
         VM_BUG_ON(!*hpage);
+#else
+        VM_BUG_ON(*hpage);
+#endif
 
         /*
          * Prevent all access to pagetables with the exception of
@@ -1699,9 +1720,17 @@ static void collapse_huge_page(struct mm_struct *mm,
         if (!pmd_present(*pmd) || pmd_trans_huge(*pmd))
                 goto out;
 
+#ifndef CONFIG_NUMA
         new_page = *hpage;
-        if (unlikely(mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL)))
+#else
+        new_page = alloc_hugepage_vma(khugepaged_defrag(), vma, address);
+        if (unlikely(!new_page)) {
+                *hpage = ERR_PTR(-ENOMEM);
                 goto out;
+        }
+#endif
+        if (unlikely(mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL)))
+                goto out_put_page;
 
         anon_vma_lock(vma->anon_vma);
 
@@ -1730,7 +1759,7 @@ static void collapse_huge_page(struct mm_struct *mm,
                 spin_unlock(&mm->page_table_lock);
                 anon_vma_unlock(vma->anon_vma);
                 mem_cgroup_uncharge_page(new_page);
-                goto out;
+                goto out_put_page;
         }
 
         /*
@@ -1765,10 +1794,19 @@ static void collapse_huge_page(struct mm_struct *mm,
         mm->nr_ptes--;
         spin_unlock(&mm->page_table_lock);
 
+#ifndef CONFIG_NUMA
         *hpage = NULL;
+#endif
         khugepaged_pages_collapsed++;
 out:
         up_write(&mm->mmap_sem);
+        return;
+
+out_put_page:
+#ifdef CONFIG_NUMA
+        put_page(new_page);
+#endif
+        goto out;
 }
 
 static int khugepaged_scan_pmd(struct mm_struct *mm,
@@ -2001,11 +2039,16 @@ static void khugepaged_do_scan(struct page **hpage)
         while (progress < pages) {
                 cond_resched();
 
+#ifndef CONFIG_NUMA
                 if (!*hpage) {
                         *hpage = alloc_hugepage(khugepaged_defrag());
                         if (unlikely(!*hpage))
                                 break;
                 }
+#else
+                if (IS_ERR(*hpage))
+                        break;
+#endif
 
                 spin_lock(&khugepaged_mm_lock);
                 if (!khugepaged_scan.mm_slot)
@@ -2020,37 +2063,55 @@ static void khugepaged_do_scan(struct page **hpage)
         }
 }
 
+static void khugepaged_alloc_sleep(void)
+{
+        DEFINE_WAIT(wait);
+        add_wait_queue(&khugepaged_wait, &wait);
+        schedule_timeout_interruptible(
+                msecs_to_jiffies(
+                        khugepaged_alloc_sleep_millisecs));
+        remove_wait_queue(&khugepaged_wait, &wait);
+}
+
+#ifndef CONFIG_NUMA
 static struct page *khugepaged_alloc_hugepage(void)
 {
         struct page *hpage;
 
         do {
                 hpage = alloc_hugepage(khugepaged_defrag());
-                if (!hpage) {
-                        DEFINE_WAIT(wait);
-                        add_wait_queue(&khugepaged_wait, &wait);
-                        schedule_timeout_interruptible(
-                                msecs_to_jiffies(
-                                        khugepaged_alloc_sleep_millisecs));
-                        remove_wait_queue(&khugepaged_wait, &wait);
-                }
+                if (!hpage)
+                        khugepaged_alloc_sleep();
         } while (unlikely(!hpage) &&
                  likely(khugepaged_enabled()));
         return hpage;
 }
+#endif
 
 static void khugepaged_loop(void)
 {
         struct page *hpage;
 
+#ifdef CONFIG_NUMA
+        hpage = NULL;
+#endif
         while (likely(khugepaged_enabled())) {
+#ifndef CONFIG_NUMA
                 hpage = khugepaged_alloc_hugepage();
                 if (unlikely(!hpage))
                         break;
+#else
+                if (IS_ERR(hpage)) {
+                        khugepaged_alloc_sleep();
+                        hpage = NULL;
+                }
+#endif
 
                 khugepaged_do_scan(&hpage);
+#ifndef CONFIG_NUMA
                 if (hpage)
                         put_page(hpage);
+#endif
                 if (khugepaged_has_work()) {
                         DEFINE_WAIT(wait);
                         if (!khugepaged_scan_sleep_millisecs)