[PATCH 53 of 66] add numa awareness to hugepage allocations

Andrea Arcangeli
2010-11-03T15:36:38Z

From: Andrea Arcangeli <aarcange@redhat.com>

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>
---

diff --git a/include/linux/gfp.h b/include/linux/gfp.h
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -330,14 +330,17 @@ alloc_pages(gfp_t gfp_mask, unsigned int
{
return alloc_pages_current(gfp_mask, order);
}
-extern struct page *alloc_page_vma(gfp_t gfp_mask,
+extern struct page *alloc_pages_vma(gfp_t gfp_mask, int order,
struct vm_area_struct *vma, unsigned long addr);
#else
#define alloc_pages(gfp_mask, order) \
alloc_pages_node(numa_node_id(), gfp_mask, order)
-#define alloc_page_vma(gfp_mask, vma, addr) alloc_pages(gfp_mask, 0)
+#define alloc_pages_vma(gfp_mask, order, vma, addr) \
+ alloc_pages(gfp_mask, order)
#endif
#define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)
+#define alloc_page_vma(gfp_mask, vma, addr) \
+ alloc_pages_vma(gfp_mask, 0, vma, addr)

extern unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order);
extern unsigned long get_zeroed_page(gfp_t gfp_mask);
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -620,11 +620,26 @@ static int __do_huge_pmd_anonymous_page(
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
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))) {
@@ -858,7 +874,8 @@ int do_huge_pmd_wp_page(struct mm_struct

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;

@@ -1655,7 +1672,11 @@ static void collapse_huge_page(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
@@ -1693,7 +1714,15 @@ static void collapse_huge_page(struct mm
if (!pmd_present(*pmd) || pmd_trans_huge(*pmd))
goto out;

+#ifndef CONFIG_NUMA
new_page = *hpage;
+#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;

@@ -1724,6 +1753,9 @@ static void collapse_huge_page(struct mm
spin_unlock(&mm->page_table_lock);
anon_vma_unlock(vma->anon_vma);
mem_cgroup_uncharge_page(new_page);
+#ifdef CONFIG_NUMA
+ put_page(new_page);
+#endif
goto out;
}

@@ -1759,7 +1791,9 @@ static void collapse_huge_page(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);
@@ -1995,11 +2029,16 @@ static void khugepaged_do_scan(struct pa
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)
@@ -2014,37 +2053,55 @@ static void khugepaged_do_scan(struct pa
}
}

+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)
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1794,7 +1794,7 @@ static struct page *alloc_page_interleav
}

/**
- * alloc_page_vma - Allocate a page for a VMA.
+ * alloc_pages_vma - Allocate a page for a VMA.
*
* @gfp:
* %GFP_USER user allocation.
@@ -1803,6 +1803,7 @@ static struct page *alloc_page_interleav
* %GFP_FS allocation should not call back into a file system.
* %GFP_ATOMIC don't sleep.
*
+ * @order:Order of the GFP allocation.
* @vma: Pointer to VMA or NULL if not available.
* @addr: Virtual Address of the allocation. Must be inside the VMA.
*
@@ -1816,7 +1817,8 @@ static struct page *alloc_page_interleav
* Should be called with the mm_sem of the vma hold.
*/
struct page *
-alloc_page_vma(gfp_t gfp, struct vm_area_struct *vma, unsigned long addr)
+alloc_pages_vma(gfp_t gfp, int order, struct vm_area_struct *vma,
+ unsigned long addr)
{
struct mempolicy *pol = get_vma_policy(current, vma, addr);
struct zonelist *zl;
@@ -1828,7 +1830,7 @@ alloc_page_vma(gfp_t gfp, struct vm_area

nid = interleave_nid(pol, vma, addr, PAGE_SHIFT);
mpol_cond_put(pol);
- page = alloc_page_interleave(gfp, 0, nid);
+ page = alloc_page_interleave(gfp, order, nid);
put_mems_allowed();
return page;
}
@@ -1837,7 +1839,7 @@ alloc_page_vma(gfp_t gfp, struct vm_area
/*
* slow path: ref counted shared policy
*/
- struct page *page = __alloc_pages_nodemask(gfp, 0,
+ struct page *page = __alloc_pages_nodemask(gfp, order,
zl, policy_nodemask(gfp, pol));
__mpol_put(pol);
put_mems_allowed();
@@ -1846,7 +1848,8 @@ alloc_page_vma(gfp_t gfp, struct vm_area
/*
* fast path: default or task policy
*/
- page = __alloc_pages_nodemask(gfp, 0, zl, policy_nodemask(gfp, pol));
+ page = __alloc_pages_nodemask(gfp, order, zl,
+ policy_nodemask(gfp, pol));
put_mems_allowed();
return page;
}