[PATCH 0/3] vmalloc enhancements

[PATCH 0/3] vmalloc enhancements

[Roman Gushchin]

The patchset contains few changes to the vmalloc code, which are
leading to some performance gains and code simplification.

Also, it exports a number of pages, used by vmalloc(),
in /proc/meminfo.

Patch (1) removes some redundancy on __vunmap().
Patch (2) separates memory allocation and data initialization
  in alloc_vmap_area()
Patch (3) adds vmalloc counter to /proc/meminfo.

RFC->v1:
  - removed bogus empty lines (suggested by Matthew Wilcox)
  - made nr_vmalloc_pages static (suggested by Matthew Wilcox)
  - dropped patch 3 from RFC patchset, will post later with
  some other changes
  - dropped RFC

Roman Gushchin (3):
  mm: refactor __vunmap() to avoid duplicated call to find_vm_area()
  mm: separate memory allocation and actual work in alloc_vmap_area()
  mm: show number of vmalloc pages in /proc/meminfo

 fs/proc/meminfo.c       |   2 +-
 include/linux/vmalloc.h |   2 +
 mm/vmalloc.c            | 107 ++++++++++++++++++++++++++--------------
 3 files changed, 73 insertions(+), 38 deletions(-)

-- 
2.19.2

[PATCH 1/3] mm: refactor __vunmap() to avoid duplicated call to find_vm_area()

[Roman Gushchin]

__vunmap() calls find_vm_area() twice without an obvious reason:
first directly to get the area pointer, second indirectly by calling
remove_vm_area(), which is again searching for the area.

To remove this redundancy, let's split remove_vm_area() into
__remove_vm_area(struct vmap_area *), which performs the actual area
removal, and remove_vm_area(const void *addr) wrapper, which can
be used everywhere, where it has been used before.

On my test setup, I've got up to 12% speed up on vfree()'ing 1000000
of 4-pages vmalloc blocks.

Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Matthew Wilcox <willy@infradead.org>
---
 mm/vmalloc.c | 47 +++++++++++++++++++++++++++--------------------
 1 file changed, 27 insertions(+), 20 deletions(-)

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 871e41c55e23..7660e3ef4133 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1462,6 +1462,24 @@ struct vm_struct *find_vm_area(const void *addr)
 	return NULL;
 }
 
+static struct vm_struct *__remove_vm_area(struct vmap_area *va)
+{
+	struct vm_struct *vm = va->vm;
+
+	might_sleep();
+
+	spin_lock(&vmap_area_lock);
+	va->vm = NULL;
+	va->flags &= ~VM_VM_AREA;
+	va->flags |= VM_LAZY_FREE;
+	spin_unlock(&vmap_area_lock);
+
+	kasan_free_shadow(vm);
+	free_unmap_vmap_area(va);
+
+	return vm;
+}
+
 /**
  *	remove_vm_area  -  find and remove a continuous kernel virtual area
  *	@addr:		base address
@@ -1472,31 +1490,20 @@ struct vm_struct *find_vm_area(const void *addr)
  */
 struct vm_struct *remove_vm_area(const void *addr)
 {
+	struct vm_struct *vm = NULL;
 	struct vmap_area *va;
 
-	might_sleep();
-
 	va = find_vmap_area((unsigned long)addr);
-	if (va && va->flags & VM_VM_AREA) {
-		struct vm_struct *vm = va->vm;
-
-		spin_lock(&vmap_area_lock);
-		va->vm = NULL;
-		va->flags &= ~VM_VM_AREA;
-		va->flags |= VM_LAZY_FREE;
-		spin_unlock(&vmap_area_lock);
-
-		kasan_free_shadow(vm);
-		free_unmap_vmap_area(va);
+	if (va && va->flags & VM_VM_AREA)
+		vm = __remove_vm_area(va);
 
-		return vm;
-	}
-	return NULL;
+	return vm;
 }
 
 static void __vunmap(const void *addr, int deallocate_pages)
 {
 	struct vm_struct *area;
+	struct vmap_area *va;
 
 	if (!addr)
 		return;
@@ -1505,17 +1512,18 @@ static void __vunmap(const void *addr, int deallocate_pages)
 			addr))
 		return;
 
-	area = find_vmap_area((unsigned long)addr)->vm;
-	if (unlikely(!area)) {
+	va = find_vmap_area((unsigned long)addr);
+	if (unlikely(!va || !va->vm)) {
 		WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n",
 				addr);
 		return;
 	}
 
+	area = va->vm;
 	debug_check_no_locks_freed(area->addr, get_vm_area_size(area));
 	debug_check_no_obj_freed(area->addr, get_vm_area_size(area));
 
-	remove_vm_area(addr);
+	__remove_vm_area(va);
 	if (deallocate_pages) {
 		int i;
 
@@ -1530,7 +1538,6 @@ static void __vunmap(const void *addr, int deallocate_pages)
 	}
 
 	kfree(area);
-	return;
 }
 
 static inline void __vfree_deferred(const void *addr)
-- 
2.19.2

[PATCH 2/3] mm: separate memory allocation and actual work in alloc_vmap_area()

[Roman Gushchin]

alloc_vmap_area() is allocating memory for the vmap_area, and
performing the actual lookup of the vm area and vmap_area
initialization.

This prevents us from using a pre-allocated memory for the map_area
structure, which can be used in some cases to minimize the number
of required memory allocations.

Let's keep the memory allocation part in alloc_vmap_area() and
separate everything else into init_vmap_area().

Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Matthew Wilcox <willy@infradead.org>
---
 mm/vmalloc.c | 50 +++++++++++++++++++++++++++++++++-----------------
 1 file changed, 33 insertions(+), 17 deletions(-)

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 7660e3ef4133..042175d7d95f 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -395,16 +395,10 @@ static void purge_vmap_area_lazy(void);
 
 static BLOCKING_NOTIFIER_HEAD(vmap_notify_list);
 
-/*
- * Allocate a region of KVA of the specified size and alignment, within the
- * vstart and vend.
- */
-static struct vmap_area *alloc_vmap_area(unsigned long size,
-				unsigned long align,
-				unsigned long vstart, unsigned long vend,
-				int node, gfp_t gfp_mask)
+static int init_vmap_area(struct vmap_area *va, unsigned long size,
+			  unsigned long align, unsigned long vstart,
+			  unsigned long vend, int node, gfp_t gfp_mask)
 {
-	struct vmap_area *va;
 	struct rb_node *n;
 	unsigned long addr;
 	int purged = 0;
@@ -416,11 +410,6 @@ static struct vmap_area *alloc_vmap_area(unsigned long size,
 
 	might_sleep();
 
-	va = kmalloc_node(sizeof(struct vmap_area),
-			gfp_mask & GFP_RECLAIM_MASK, node);
-	if (unlikely(!va))
-		return ERR_PTR(-ENOMEM);
-
 	/*
 	 * Only scan the relevant parts containing pointers to other objects
 	 * to avoid false negatives.
@@ -512,7 +501,7 @@ static struct vmap_area *alloc_vmap_area(unsigned long size,
 	BUG_ON(va->va_start < vstart);
 	BUG_ON(va->va_end > vend);
 
-	return va;
+	return 0;
 
 overflow:
 	spin_unlock(&vmap_area_lock);
@@ -534,8 +523,35 @@ static struct vmap_area *alloc_vmap_area(unsigned long size,
 	if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit())
 		pr_warn("vmap allocation for size %lu failed: use vmalloc=<size> to increase size\n",
 			size);
-	kfree(va);
-	return ERR_PTR(-EBUSY);
+
+	return -EBUSY;
+}
+
+/*
+ * Allocate a region of KVA of the specified size and alignment, within the
+ * vstart and vend.
+ */
+static struct vmap_area *alloc_vmap_area(unsigned long size,
+					 unsigned long align,
+					 unsigned long vstart,
+					 unsigned long vend,
+					 int node, gfp_t gfp_mask)
+{
+	struct vmap_area *va;
+	int ret;
+
+	va = kmalloc_node(sizeof(struct vmap_area),
+			gfp_mask & GFP_RECLAIM_MASK, node);
+	if (unlikely(!va))
+		return ERR_PTR(-ENOMEM);
+
+	ret = init_vmap_area(va, size, align, vstart, vend, node, gfp_mask);
+	if (ret) {
+		kfree(va);
+		return ERR_PTR(ret);
+	}
+
+	return va;
 }
 
 int register_vmap_purge_notifier(struct notifier_block *nb)
-- 
2.19.2

[PATCH 3/3] mm: show number of vmalloc pages in /proc/meminfo

[Roman Gushchin]

Vmalloc() is getting more and more used these days (kernel stacks,
bpf and percpu allocator are new top users), and the total %
of memory consumed by vmalloc() can be pretty significant
and changes dynamically.

/proc/meminfo is the best place to display this information:
its top goal is to show top consumers of the memory.

Since the VmallocUsed field in /proc/meminfo is not in use
for quite a long time (it has been defined to 0 by the
commit a5ad88ce8c7f ("mm: get rid of 'vmalloc_info' from
/proc/meminfo")), let's reuse it for showing the actual
physical memory consumption of vmalloc().

Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
---
 fs/proc/meminfo.c       |  2 +-
 include/linux/vmalloc.h |  2 ++
 mm/vmalloc.c            | 10 ++++++++++
 3 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/fs/proc/meminfo.c b/fs/proc/meminfo.c
index 568d90e17c17..465ea0153b2a 100644
--- a/fs/proc/meminfo.c
+++ b/fs/proc/meminfo.c
@@ -120,7 +120,7 @@ static int meminfo_proc_show(struct seq_file *m, void *v)
 	show_val_kb(m, "Committed_AS:   ", committed);
 	seq_printf(m, "VmallocTotal:   %8lu kB\n",
 		   (unsigned long)VMALLOC_TOTAL >> 10);
-	show_val_kb(m, "VmallocUsed:    ", 0ul);
+	show_val_kb(m, "VmallocUsed:    ", vmalloc_nr_pages());
 	show_val_kb(m, "VmallocChunk:   ", 0ul);
 	show_val_kb(m, "Percpu:         ", pcpu_nr_pages());
 
diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index 398e9c95cd61..0b497408272b 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -63,10 +63,12 @@ extern void vm_unmap_aliases(void);
 
 #ifdef CONFIG_MMU
 extern void __init vmalloc_init(void);
+extern unsigned long vmalloc_nr_pages(void);
 #else
 static inline void vmalloc_init(void)
 {
 }
+static inline unsigned long vmalloc_nr_pages(void) { return 0; }
 #endif
 
 extern void *vmalloc(unsigned long size);
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 042175d7d95f..efca916940e9 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -340,6 +340,13 @@ static unsigned long cached_align;
 
 static unsigned long vmap_area_pcpu_hole;
 
+static atomic_long_t nr_vmalloc_pages;
+
+unsigned long vmalloc_nr_pages(void)
+{
+	return atomic_long_read(&nr_vmalloc_pages);
+}
+
 static struct vmap_area *__find_vmap_area(unsigned long addr)
 {
 	struct rb_node *n = vmap_area_root.rb_node;
@@ -1549,6 +1556,7 @@ static void __vunmap(const void *addr, int deallocate_pages)
 			BUG_ON(!page);
 			__free_pages(page, 0);
 		}
+		atomic_long_sub(area->nr_pages, &nr_vmalloc_pages);
 
 		kvfree(area->pages);
 	}
@@ -1717,12 +1725,14 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
 		if (unlikely(!page)) {
 			/* Successfully allocated i pages, free them in __vunmap() */
 			area->nr_pages = i;
+			atomic_long_add(area->nr_pages, &nr_vmalloc_pages);
 			goto fail;
 		}
 		area->pages[i] = page;
 		if (gfpflags_allow_blocking(gfp_mask|highmem_mask))
 			cond_resched();
 	}
+	atomic_long_add(area->nr_pages, &nr_vmalloc_pages);
 
 	if (map_vm_area(area, prot, pages))
 		goto fail;
-- 
2.19.2

Re: [PATCH 0/3] vmalloc enhancements

[Johannes Weiner]

These slipped through the cracks. +CC Andrew directly.
Andrew, if it's not too late yet, could you consider them for 5.1?

On Wed, Dec 19, 2018 at 09:37:48AM -0800, Roman Gushchin wrote:
> The patchset contains few changes to the vmalloc code, which are
> leading to some performance gains and code simplification.
> 
> Also, it exports a number of pages, used by vmalloc(),
> in /proc/meminfo.
> 
> Patch (1) removes some redundancy on __vunmap().
> Patch (2) separates memory allocation and data initialization
>   in alloc_vmap_area()
> Patch (3) adds vmalloc counter to /proc/meminfo.
> 
> RFC->v1:
>   - removed bogus empty lines (suggested by Matthew Wilcox)
>   - made nr_vmalloc_pages static (suggested by Matthew Wilcox)
>   - dropped patch 3 from RFC patchset, will post later with
>   some other changes
>   - dropped RFC
> 
> Roman Gushchin (3):
>   mm: refactor __vunmap() to avoid duplicated call to find_vm_area()
>   mm: separate memory allocation and actual work in alloc_vmap_area()
>   mm: show number of vmalloc pages in /proc/meminfo
> 
>  fs/proc/meminfo.c       |   2 +-
>  include/linux/vmalloc.h |   2 +
>  mm/vmalloc.c            | 107 ++++++++++++++++++++++++++--------------
>  3 files changed, 73 insertions(+), 38 deletions(-)
> 
> -- 
> 2.19.2
> 

Re: [PATCH 0/3] vmalloc enhancements

[Andrew Morton]

On Mon, 11 Feb 2019 14:08:22 -0500 Johannes Weiner <hannes@cmpxchg.org> wrote:

> On Wed, Dec 19, 2018 at 09:37:48AM -0800, Roman Gushchin wrote:
> > The patchset contains few changes to the vmalloc code, which are
> > leading to some performance gains and code simplification.
> > 
> > Also, it exports a number of pages, used by vmalloc(),
> > in /proc/meminfo.
>
> These slipped through the cracks. +CC Andrew directly.
> Andrew, if it's not too late yet, could you consider them for 5.1?
> 

There's been some activity in vmalloc.c lately and these have
bitrotted.  They'll need a redo, please.

Re: [PATCH 0/3] vmalloc enhancements

[Roman Gushchin]

On Mon, Feb 11, 2019 at 11:18:45AM -0800, Andrew Morton wrote:
> On Mon, 11 Feb 2019 14:08:22 -0500 Johannes Weiner <hannes@cmpxchg.org> wrote:
> 
> > On Wed, Dec 19, 2018 at 09:37:48AM -0800, Roman Gushchin wrote:
> > > The patchset contains few changes to the vmalloc code, which are
> > > leading to some performance gains and code simplification.
> > > 
> > > Also, it exports a number of pages, used by vmalloc(),
> > > in /proc/meminfo.
> >
> > These slipped through the cracks. +CC Andrew directly.
> > Andrew, if it's not too late yet, could you consider them for 5.1?
> > 
> 
> There's been some activity in vmalloc.c lately and these have
> bitrotted.  They'll need a redo, please.
> 

Will do. Thanks!

Re: [PATCH 2/3] mm: separate memory allocation and actual work in alloc_vmap_area()

[Roman Gushchin]

On Wed, Apr 17, 2019 at 03:27:56PM +0200, Vlastimil Babka wrote:
> On 3/1/19 5:48 PM, Roman Gushchin wrote:
> > On Fri, Mar 01, 2019 at 03:43:19PM +0100, Vlastimil Babka wrote:
> >> On 2/25/19 9:30 PM, Roman Gushchin wrote:
> >>> alloc_vmap_area() is allocating memory for the vmap_area, and
> >>> performing the actual lookup of the vm area and vmap_area
> >>> initialization.
> >>>
> >>> This prevents us from using a pre-allocated memory for the map_area
> >>> structure, which can be used in some cases to minimize the number
> >>> of required memory allocations.
> >>
> >> Hmm, but that doesn't happen here or in the later patch, right? The only
> >> caller of init_vmap_area() is alloc_vmap_area(). What am I missing?
> > 
> > So initially the patch was a part of a bigger patchset, which
> > tried to minimize the number of separate allocations during vmalloc(),
> > e.g. by inlining vm_struct->pages into vm_struct for small areas.
> > 
> > I temporarily dropped the rest of the patchset for some rework,
> > but decided to leave this patch, because it looks like a nice refactoring
> > in any case, and also it has been already reviewed and acked by Matthew
> > and Johannes.
> 
> OK then,
> 
> Acked-by: Vlastimil Babka <vbabka@suse.cz>

Thank you for looking into this and other patches from the series!

Btw, it looks like that recent changes in vmalloc code are in a conflict
with this patch, so I'll drop it for now, and will resend two other as v4.

Thanks!

Re: [PATCH 2/3] mm: separate memory allocation and actual work in alloc_vmap_area()

[Vlastimil Babka]

On 3/1/19 5:48 PM, Roman Gushchin wrote:
> On Fri, Mar 01, 2019 at 03:43:19PM +0100, Vlastimil Babka wrote:
>> On 2/25/19 9:30 PM, Roman Gushchin wrote:
>>> alloc_vmap_area() is allocating memory for the vmap_area, and
>>> performing the actual lookup of the vm area and vmap_area
>>> initialization.
>>>
>>> This prevents us from using a pre-allocated memory for the map_area
>>> structure, which can be used in some cases to minimize the number
>>> of required memory allocations.
>>
>> Hmm, but that doesn't happen here or in the later patch, right? The only
>> caller of init_vmap_area() is alloc_vmap_area(). What am I missing?
> 
> So initially the patch was a part of a bigger patchset, which
> tried to minimize the number of separate allocations during vmalloc(),
> e.g. by inlining vm_struct->pages into vm_struct for small areas.
> 
> I temporarily dropped the rest of the patchset for some rework,
> but decided to leave this patch, because it looks like a nice refactoring
> in any case, and also it has been already reviewed and acked by Matthew
> and Johannes.

OK then,

Acked-by: Vlastimil Babka <vbabka@suse.cz>

> Thank you for looking into it!
> 

Re: [PATCH 2/3] mm: separate memory allocation and actual work in alloc_vmap_area()

[Roman Gushchin]

On Fri, Mar 01, 2019 at 03:43:19PM +0100, Vlastimil Babka wrote:
> On 2/25/19 9:30 PM, Roman Gushchin wrote:
> > alloc_vmap_area() is allocating memory for the vmap_area, and
> > performing the actual lookup of the vm area and vmap_area
> > initialization.
> > 
> > This prevents us from using a pre-allocated memory for the map_area
> > structure, which can be used in some cases to minimize the number
> > of required memory allocations.
> 
> Hmm, but that doesn't happen here or in the later patch, right? The only
> caller of init_vmap_area() is alloc_vmap_area(). What am I missing?

So initially the patch was a part of a bigger patchset, which
tried to minimize the number of separate allocations during vmalloc(),
e.g. by inlining vm_struct->pages into vm_struct for small areas.

I temporarily dropped the rest of the patchset for some rework,
but decided to leave this patch, because it looks like a nice refactoring
in any case, and also it has been already reviewed and acked by Matthew
and Johannes.

Thank you for looking into it!

Re: [PATCH 2/3] mm: separate memory allocation and actual work in alloc_vmap_area()

[Vlastimil Babka]

On 2/25/19 9:30 PM, Roman Gushchin wrote:
> alloc_vmap_area() is allocating memory for the vmap_area, and
> performing the actual lookup of the vm area and vmap_area
> initialization.
> 
> This prevents us from using a pre-allocated memory for the map_area
> structure, which can be used in some cases to minimize the number
> of required memory allocations.

Hmm, but that doesn't happen here or in the later patch, right? The only
caller of init_vmap_area() is alloc_vmap_area(). What am I missing?

> Let's keep the memory allocation part in alloc_vmap_area() and
> separate everything else into init_vmap_area().
> 
> Signed-off-by: Roman Gushchin <guro@fb.com>
> Acked-by: Johannes Weiner <hannes@cmpxchg.org>
> Reviewed-by: Matthew Wilcox <willy@infradead.org>

[PATCH 2/3] mm: separate memory allocation and actual work in alloc_vmap_area()

[Roman Gushchin]

alloc_vmap_area() is allocating memory for the vmap_area, and
performing the actual lookup of the vm area and vmap_area
initialization.

This prevents us from using a pre-allocated memory for the map_area
structure, which can be used in some cases to minimize the number
of required memory allocations.

Let's keep the memory allocation part in alloc_vmap_area() and
separate everything else into init_vmap_area().

Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Matthew Wilcox <willy@infradead.org>
---
 mm/vmalloc.c | 50 +++++++++++++++++++++++++++++++++-----------------
 1 file changed, 33 insertions(+), 17 deletions(-)

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 8f0179895fb5..f1f19d1105c4 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -395,16 +395,10 @@ static void purge_vmap_area_lazy(void);
 
 static BLOCKING_NOTIFIER_HEAD(vmap_notify_list);
 
-/*
- * Allocate a region of KVA of the specified size and alignment, within the
- * vstart and vend.
- */
-static struct vmap_area *alloc_vmap_area(unsigned long size,
-				unsigned long align,
-				unsigned long vstart, unsigned long vend,
-				int node, gfp_t gfp_mask)
+static int init_vmap_area(struct vmap_area *va, unsigned long size,
+			  unsigned long align, unsigned long vstart,
+			  unsigned long vend, int node, gfp_t gfp_mask)
 {
-	struct vmap_area *va;
 	struct rb_node *n;
 	unsigned long addr;
 	int purged = 0;
@@ -416,11 +410,6 @@ static struct vmap_area *alloc_vmap_area(unsigned long size,
 
 	might_sleep();
 
-	va = kmalloc_node(sizeof(struct vmap_area),
-			gfp_mask & GFP_RECLAIM_MASK, node);
-	if (unlikely(!va))
-		return ERR_PTR(-ENOMEM);
-
 	/*
 	 * Only scan the relevant parts containing pointers to other objects
 	 * to avoid false negatives.
@@ -516,7 +505,7 @@ static struct vmap_area *alloc_vmap_area(unsigned long size,
 	BUG_ON(va->va_start < vstart);
 	BUG_ON(va->va_end > vend);
 
-	return va;
+	return 0;
 
 overflow:
 	spin_unlock(&vmap_area_lock);
@@ -538,8 +527,35 @@ static struct vmap_area *alloc_vmap_area(unsigned long size,
 	if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit())
 		pr_warn("vmap allocation for size %lu failed: use vmalloc=<size> to increase size\n",
 			size);
-	kfree(va);
-	return ERR_PTR(-EBUSY);
+
+	return -EBUSY;
+}
+
+/*
+ * Allocate a region of KVA of the specified size and alignment, within the
+ * vstart and vend.
+ */
+static struct vmap_area *alloc_vmap_area(unsigned long size,
+					 unsigned long align,
+					 unsigned long vstart,
+					 unsigned long vend,
+					 int node, gfp_t gfp_mask)
+{
+	struct vmap_area *va;
+	int ret;
+
+	va = kmalloc_node(sizeof(struct vmap_area),
+			gfp_mask & GFP_RECLAIM_MASK, node);
+	if (unlikely(!va))
+		return ERR_PTR(-ENOMEM);
+
+	ret = init_vmap_area(va, size, align, vstart, vend, node, gfp_mask);
+	if (ret) {
+		kfree(va);
+		return ERR_PTR(ret);
+	}
+
+	return va;
 }
 
 int register_vmap_purge_notifier(struct notifier_block *nb)
-- 
2.20.1