Commit 19809c2d authored by Michal Hocko's avatar Michal Hocko Committed by Linus Torvalds
Browse files

mm, vmalloc: use __GFP_HIGHMEM implicitly 

__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.

Link: http://lkml.kernel.org/r/20170307141020.29107-1-mhocko@kernel.org


Signed-off-by: default avatarMichal Hocko <mhocko@suse.com>
Reviewed-by: default avatarMatthew Wilcox <mawilcox@microsoft.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Cristopher Lameter <cl@linux.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 54f180d3

arch/parisc/kernel/module.c

+1 −1
Original line number Diff line number Diff line
@@ -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));

}

arch/x86/kernel/module.c

+1 −1
Original line number Diff line number Diff line
@@ -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)) {

drivers/block/drbd/drbd_bitmap.c

+1 −1
Original line number Diff line number Diff line
@@ -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;

drivers/gpu/drm/etnaviv/etnaviv_dump.c

+2 −2
Original line number Diff line number Diff line
@@ -161,8 +161,8 @@ 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;

drivers/md/dm-bufio.c

+1 −1
Original line number Diff line number Diff line
@@ -406,7 +406,7 @@ 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);

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