[RFC PATCH] mm, vmalloc: use __GFP_HIGHMEM implicitly
From: Michal Hocko
Date: Wed Feb 01 2017 - 09:05:54 EST
From: Michal Hocko <mhocko@xxxxxxxx>
__vmalloc* allows users to provide gfp flags for the underlying
allocation. This API is quite popular
$ git grep "=[[:space:]]__vmalloc\|return[[:space:]]*__vmalloc" | wc -l
77
the only problem is that many people are not aware that they really want
to give __GFP_HIGHMEM along with other flags because there is really no
reason to consume precious lowmemory on CONFIG_HIGHMEM systems for pages
which are mapped to the kernel vmalloc space. About half of users don't
use this flag, though. This signals that we make the API unnecessarily
too complex.
This patch simply uses __GFP_HIGHMEM implicitly when allocating pages to
be mapped to the vmalloc space. Current users which add __GFP_HIGHMEM
are simplified and drop the flag.
Signed-off-by: Michal Hocko <mhocko@xxxxxxxx>
---
Hi,
this is based on top of [1]. I believe it was Al who has brought this
up quite some time ago (or maybe I just misremember). The explicit
usage of __GFP_HIGHMEM in __vmalloc* seems to be too much to ask from
users. I believe there is no user which doesn't want vmalloc pages be
in the highmem but I might be missing something. There is vmalloc_32*
API but that uses GFP_DMA* explicitly which overrides __GFP_HIGHMEM. So
all current users _should_ be safe to use __GFP_HIGHMEM unconditionally.
This patch should simplify things and fix many users which consume
lowmem for no good reason.
I am sending this as an RFC to get some feedback, I even haven't compile
tested it yet.
Any comments are welcome.
[1] http://lkml.kernel.org/r/20170130094940.13546-1-mhocko@xxxxxxxxxx
arch/parisc/kernel/module.c | 2 +-
arch/x86/kernel/module.c | 2 +-
drivers/block/drbd/drbd_bitmap.c | 2 +-
drivers/gpu/drm/etnaviv/etnaviv_dump.c | 4 ++--
drivers/md/dm-bufio.c | 2 +-
fs/btrfs/free-space-tree.c | 3 +--
fs/file.c | 2 +-
fs/xfs/kmem.c | 2 +-
include/drm/drm_mem_util.h | 3 +--
kernel/bpf/core.c | 9 +++------
kernel/bpf/syscall.c | 3 +--
kernel/fork.c | 2 +-
kernel/groups.c | 2 +-
kernel/module.c | 2 +-
mm/kasan/kasan.c | 2 +-
mm/nommu.c | 3 +--
mm/util.c | 2 +-
mm/vmalloc.c | 14 +++++++-------
net/ceph/ceph_common.c | 2 +-
net/netfilter/x_tables.c | 3 +--
20 files changed, 29 insertions(+), 37 deletions(-)
diff --git a/arch/parisc/kernel/module.c b/arch/parisc/kernel/module.c
index a0ecdb4abcc8..3d4f5660a2e0 100644
--- a/arch/parisc/kernel/module.c
+++ b/arch/parisc/kernel/module.c
@@ -218,7 +218,7 @@ void *module_alloc(unsigned long size)
* easier than trying to map the text, data, init_text and
* init_data correctly */
return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
- GFP_KERNEL | __GFP_HIGHMEM,
+ GFP_KERNEL,
PAGE_KERNEL_RWX, 0, NUMA_NO_NODE,
__builtin_return_address(0));
}
diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c
index 477ae806c2fa..f67bd3205df7 100644
--- a/arch/x86/kernel/module.c
+++ b/arch/x86/kernel/module.c
@@ -85,7 +85,7 @@ void *module_alloc(unsigned long size)
p = __vmalloc_node_range(size, MODULE_ALIGN,
MODULES_VADDR + get_module_load_offset(),
- MODULES_END, GFP_KERNEL | __GFP_HIGHMEM,
+ MODULES_END, GFP_KERNEL,
PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE,
__builtin_return_address(0));
if (p && (kasan_module_alloc(p, size) < 0)) {
diff --git a/drivers/block/drbd/drbd_bitmap.c b/drivers/block/drbd/drbd_bitmap.c
index dece26f119d4..a804a4107fbc 100644
--- a/drivers/block/drbd/drbd_bitmap.c
+++ b/drivers/block/drbd/drbd_bitmap.c
@@ -409,7 +409,7 @@ static struct page **bm_realloc_pages(struct drbd_bitmap *b, unsigned long want)
new_pages = kzalloc(bytes, GFP_NOIO | __GFP_NOWARN);
if (!new_pages) {
new_pages = __vmalloc(bytes,
- GFP_NOIO | __GFP_HIGHMEM | __GFP_ZERO,
+ GFP_NOIO | __GFP_ZERO,
PAGE_KERNEL);
if (!new_pages)
return NULL;
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_dump.c b/drivers/gpu/drm/etnaviv/etnaviv_dump.c
index af65491a78e2..32d2ea18a587 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_dump.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_dump.c
@@ -160,8 +160,8 @@ void etnaviv_core_dump(struct etnaviv_gpu *gpu)
file_size += sizeof(*iter.hdr) * n_obj;
/* Allocate the file in vmalloc memory, it's likely to be big */
- iter.start = __vmalloc(file_size, GFP_KERNEL | __GFP_HIGHMEM |
- __GFP_NOWARN | __GFP_NORETRY, PAGE_KERNEL);
+ iter.start = __vmalloc(file_size, GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY,
+ PAGE_KERNEL);
if (!iter.start) {
dev_warn(gpu->dev, "failed to allocate devcoredump file\n");
return;
diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c
index d36d427a9efb..f183af90f447 100644
--- a/drivers/md/dm-bufio.c
+++ b/drivers/md/dm-bufio.c
@@ -403,7 +403,7 @@ static void *alloc_buffer_data(struct dm_bufio_client *c, gfp_t gfp_mask,
if (gfp_mask & __GFP_NORETRY)
noio_flag = memalloc_noio_save();
- ptr = __vmalloc(c->block_size, gfp_mask | __GFP_HIGHMEM, PAGE_KERNEL);
+ ptr = __vmalloc(c->block_size, gfp_mask, PAGE_KERNEL);
if (gfp_mask & __GFP_NORETRY)
memalloc_noio_restore(noio_flag);
diff --git a/fs/btrfs/free-space-tree.c b/fs/btrfs/free-space-tree.c
index ff0c55337c2e..844473309b37 100644
--- a/fs/btrfs/free-space-tree.c
+++ b/fs/btrfs/free-space-tree.c
@@ -167,8 +167,7 @@ static u8 *alloc_bitmap(u32 bitmap_size)
if (mem)
return mem;
- return __vmalloc(bitmap_size, GFP_NOFS | __GFP_HIGHMEM | __GFP_ZERO,
- PAGE_KERNEL);
+ return __vmalloc(bitmap_size, GFP_NOFS | __GFP_ZERO, PAGE_KERNEL);
}
int convert_free_space_to_bitmaps(struct btrfs_trans_handle *trans,
diff --git a/fs/file.c b/fs/file.c
index 69d6990e3021..5ddf189f3a7e 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -42,7 +42,7 @@ static void *alloc_fdmem(size_t size)
if (data != NULL)
return data;
}
- return __vmalloc(size, GFP_KERNEL_ACCOUNT | __GFP_HIGHMEM, PAGE_KERNEL);
+ return __vmalloc(size, GFP_KERNEL_ACCOUNT, PAGE_KERNEL);
}
static void __free_fdtable(struct fdtable *fdt)
diff --git a/fs/xfs/kmem.c b/fs/xfs/kmem.c
index 339c696bbc01..d3bf13bf30b5 100644
--- a/fs/xfs/kmem.c
+++ b/fs/xfs/kmem.c
@@ -84,7 +84,7 @@ kmem_zalloc_large(size_t size, xfs_km_flags_t flags)
noio_flag = memalloc_noio_save();
lflags = kmem_flags_convert(flags);
- ptr = __vmalloc(size, lflags | __GFP_HIGHMEM | __GFP_ZERO, PAGE_KERNEL);
+ ptr = __vmalloc(size, lflags | __GFP_ZERO, PAGE_KERNEL);
if ((current->flags & PF_FSTRANS) || (flags & KM_NOFS))
memalloc_noio_restore(noio_flag);
diff --git a/include/drm/drm_mem_util.h b/include/drm/drm_mem_util.h
index 70d4e221a3ad..9178d9976603 100644
--- a/include/drm/drm_mem_util.h
+++ b/include/drm/drm_mem_util.h
@@ -37,8 +37,7 @@ static __inline__ void *drm_calloc_large(size_t nmemb, size_t size)
if (size * nmemb <= PAGE_SIZE)
return kcalloc(nmemb, size, GFP_KERNEL);
- return __vmalloc(size * nmemb,
- GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO, PAGE_KERNEL);
+ return __vmalloc(size * nmemb, GFP_KERNEL | __GFP_ZERO, PAGE_KERNEL);
}
/* Modeled after cairo's malloc_ab, it's like calloc but without the zeroing. */
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index fddd76b1b627..ab2728883239 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -73,8 +73,7 @@ void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, uns
struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags)
{
- gfp_t gfp_flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO |
- gfp_extra_flags;
+ gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
struct bpf_prog_aux *aux;
struct bpf_prog *fp;
@@ -102,8 +101,7 @@ EXPORT_SYMBOL_GPL(bpf_prog_alloc);
struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
gfp_t gfp_extra_flags)
{
- gfp_t gfp_flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO |
- gfp_extra_flags;
+ gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
struct bpf_prog *fp;
u32 pages, delta;
int ret;
@@ -436,8 +434,7 @@ static int bpf_jit_blind_insn(const struct bpf_insn *from,
static struct bpf_prog *bpf_prog_clone_create(struct bpf_prog *fp_other,
gfp_t gfp_extra_flags)
{
- gfp_t gfp_flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO |
- gfp_extra_flags;
+ gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
struct bpf_prog *fp;
fp = __vmalloc(fp_other->pages * PAGE_SIZE, gfp_flags, PAGE_KERNEL);
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 08a4d287226b..88e749fd6a40 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -67,8 +67,7 @@ void *bpf_map_area_alloc(size_t size)
return area;
}
- return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM | flags,
- PAGE_KERNEL);
+ return __vmalloc(size, GFP_KERNEL | flags, PAGE_KERNEL);
}
void bpf_map_area_free(void *area)
diff --git a/kernel/fork.c b/kernel/fork.c
index 1f4bf6d2e45a..fb4e8b2886a1 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -192,7 +192,7 @@ static unsigned long *alloc_thread_stack_node(struct task_struct *tsk, int node)
stack = __vmalloc_node_range(THREAD_SIZE, THREAD_SIZE,
VMALLOC_START, VMALLOC_END,
- THREADINFO_GFP | __GFP_HIGHMEM,
+ THREADINFO_GFP,
PAGE_KERNEL,
0, node, __builtin_return_address(0));
diff --git a/kernel/groups.c b/kernel/groups.c
index 8dd7a61b7115..d09727692a2a 100644
--- a/kernel/groups.c
+++ b/kernel/groups.c
@@ -18,7 +18,7 @@ struct group_info *groups_alloc(int gidsetsize)
len = sizeof(struct group_info) + sizeof(kgid_t) * gidsetsize;
gi = kmalloc(len, GFP_KERNEL_ACCOUNT|__GFP_NOWARN|__GFP_NORETRY);
if (!gi)
- gi = __vmalloc(len, GFP_KERNEL_ACCOUNT|__GFP_HIGHMEM, PAGE_KERNEL);
+ gi = __vmalloc(len, GFP_KERNEL_ACCOUNT, PAGE_KERNEL);
if (!gi)
return NULL;
diff --git a/kernel/module.c b/kernel/module.c
index f4e91dbc2995..6046c8e1d8b9 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -2848,7 +2848,7 @@ static int copy_module_from_user(const void __user *umod, unsigned long len,
/* Suck in entire file: we'll want most of it. */
info->hdr = __vmalloc(info->len,
- GFP_KERNEL | __GFP_HIGHMEM | __GFP_NOWARN, PAGE_KERNEL);
+ GFP_KERNEL | __GFP_NOWARN, PAGE_KERNEL);
if (!info->hdr)
return -ENOMEM;
diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c
index 5f6e09c88d25..2ae297009e85 100644
--- a/mm/kasan/kasan.c
+++ b/mm/kasan/kasan.c
@@ -679,7 +679,7 @@ int kasan_module_alloc(void *addr, size_t size)
ret = __vmalloc_node_range(shadow_size, 1, shadow_start,
shadow_start + shadow_size,
- GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO,
+ GFP_KERNEL | __GFP_ZERO,
PAGE_KERNEL, VM_NO_GUARD, NUMA_NO_NODE,
__builtin_return_address(0));
diff --git a/mm/nommu.c b/mm/nommu.c
index bee76e6cd4e5..5ee7f8ca7854 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -245,8 +245,7 @@ void *vmalloc_user(unsigned long size)
{
void *ret;
- ret = __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO,
- PAGE_KERNEL);
+ ret = __vmalloc(size, GFP_KERNEL | __GFP_ZERO, PAGE_KERNEL);
if (ret) {
struct vm_area_struct *vma;
diff --git a/mm/util.c b/mm/util.c
index f50100ca73ce..695f7a9d645e 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -371,7 +371,7 @@ void *kvmalloc_node(size_t size, gfp_t flags, int node)
if (ret || size <= PAGE_SIZE)
return ret;
- return __vmalloc_node_flags(size, node, flags | __GFP_HIGHMEM);
+ return __vmalloc_node_flags(size, node, flags);
}
EXPORT_SYMBOL(kvmalloc_node);
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 3b90a7f8380c..d811bf99caa6 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1619,7 +1619,7 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
struct page **pages;
unsigned int nr_pages, array_size, i;
const gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO;
- const gfp_t alloc_mask = gfp_mask | __GFP_NOWARN;
+ const gfp_t alloc_mask = gfp_mask | __GFP_HIGHMEM | __GFP_NOWARN;
nr_pages = get_vm_area_size(area) >> PAGE_SHIFT;
array_size = (nr_pages * sizeof(struct page *));
@@ -1783,7 +1783,7 @@ void *__vmalloc_node_flags(unsigned long size,
void *vmalloc(unsigned long size)
{
return __vmalloc_node_flags(size, NUMA_NO_NODE,
- GFP_KERNEL | __GFP_HIGHMEM);
+ GFP_KERNEL);
}
EXPORT_SYMBOL(vmalloc);
@@ -1800,7 +1800,7 @@ EXPORT_SYMBOL(vmalloc);
void *vzalloc(unsigned long size)
{
return __vmalloc_node_flags(size, NUMA_NO_NODE,
- GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO);
+ GFP_KERNEL | __GFP_ZERO);
}
EXPORT_SYMBOL(vzalloc);
@@ -1817,7 +1817,7 @@ void *vmalloc_user(unsigned long size)
void *ret;
ret = __vmalloc_node(size, SHMLBA,
- GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO,
+ GFP_KERNEL | __GFP_ZERO,
PAGE_KERNEL, NUMA_NO_NODE,
__builtin_return_address(0));
if (ret) {
@@ -1841,7 +1841,7 @@ EXPORT_SYMBOL(vmalloc_user);
*/
void *vmalloc_node(unsigned long size, int node)
{
- return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL,
+ return __vmalloc_node(size, 1, GFP_KERNEL, PAGE_KERNEL,
node, __builtin_return_address(0));
}
EXPORT_SYMBOL(vmalloc_node);
@@ -1861,7 +1861,7 @@ EXPORT_SYMBOL(vmalloc_node);
void *vzalloc_node(unsigned long size, int node)
{
return __vmalloc_node_flags(size, node,
- GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO);
+ GFP_KERNEL | __GFP_ZERO);
}
EXPORT_SYMBOL(vzalloc_node);
@@ -1883,7 +1883,7 @@ EXPORT_SYMBOL(vzalloc_node);
void *vmalloc_exec(unsigned long size)
{
- return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC,
+ return __vmalloc_node(size, 1, GFP_KERNEL, PAGE_KERNEL_EXEC,
NUMA_NO_NODE, __builtin_return_address(0));
}
diff --git a/net/ceph/ceph_common.c b/net/ceph/ceph_common.c
index 464e88599b9d..73d4739fcbe0 100644
--- a/net/ceph/ceph_common.c
+++ b/net/ceph/ceph_common.c
@@ -187,7 +187,7 @@ void *ceph_kvmalloc(size_t size, gfp_t flags)
return ptr;
}
- return __vmalloc(size, flags | __GFP_HIGHMEM, PAGE_KERNEL);
+ return __vmalloc(size, flags, PAGE_KERNEL);
}
diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c
index d529989f5791..e58ecff638b3 100644
--- a/net/netfilter/x_tables.c
+++ b/net/netfilter/x_tables.c
@@ -998,8 +998,7 @@ struct xt_table_info *xt_alloc_table_info(unsigned int size)
if (sz <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER))
info = kmalloc(sz, GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY);
if (!info) {
- info = __vmalloc(sz, GFP_KERNEL | __GFP_NOWARN |
- __GFP_NORETRY | __GFP_HIGHMEM,
+ info = __vmalloc(sz, GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY,
PAGE_KERNEL);
if (!info)
return NULL;
--
2.11.0