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authorSong Liu <song@kernel.org>2022-04-15 19:44:10 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2022-04-19 22:08:57 +0300
commit559089e0a93d44280ec3ab478830af319c56dbe3 (patch)
treeb4480a72841a160200f7ba9d3097d9db1d92cf9c /mm/vmalloc.c
parentb7f73403a3e922c20bb278ba3cfcc3c61930d82a (diff)
downloadlinux-559089e0a93d44280ec3ab478830af319c56dbe3.tar.xz
vmalloc: replace VM_NO_HUGE_VMAP with VM_ALLOW_HUGE_VMAP
Huge page backed vmalloc memory could benefit performance in many cases. However, some users of vmalloc may not be ready to handle huge pages for various reasons: hardware constraints, potential pages split, etc. VM_NO_HUGE_VMAP was introduced to allow vmalloc users to opt-out huge pages. However, it is not easy to track down all the users that require the opt-out, as the allocation are passed different stacks and may cause issues in different layers. To address this issue, replace VM_NO_HUGE_VMAP with an opt-in flag, VM_ALLOW_HUGE_VMAP, so that users that benefit from huge pages could ask specificially. Also, remove vmalloc_no_huge() and add opt-in helper vmalloc_huge(). Fixes: fac54e2bfb5b ("x86/Kconfig: Select HAVE_ARCH_HUGE_VMALLOC with HAVE_ARCH_HUGE_VMAP") Link: https://lore.kernel.org/netdev/14444103-d51b-0fb3-ee63-c3f182f0b546@molgen.mpg.de/" Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Song Liu <song@kernel.org> Reviewed-by: Rik van Riel <riel@surriel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/vmalloc.c')
-rw-r--r--mm/vmalloc.c17
1 files changed, 10 insertions, 7 deletions
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 0b17498a34f1..07da85ae825b 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -3095,7 +3095,7 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align,
return NULL;
}
- if (vmap_allow_huge && !(vm_flags & VM_NO_HUGE_VMAP)) {
+ if (vmap_allow_huge && (vm_flags & VM_ALLOW_HUGE_VMAP)) {
unsigned long size_per_node;
/*
@@ -3262,21 +3262,24 @@ void *vmalloc(unsigned long size)
EXPORT_SYMBOL(vmalloc);
/**
- * vmalloc_no_huge - allocate virtually contiguous memory using small pages
- * @size: allocation size
+ * vmalloc_huge - allocate virtually contiguous memory, allow huge pages
+ * @size: allocation size
+ * @gfp_mask: flags for the page level allocator
*
- * Allocate enough non-huge pages to cover @size from the page level
+ * Allocate enough pages to cover @size from the page level
* allocator and map them into contiguous kernel virtual space.
+ * If @size is greater than or equal to PMD_SIZE, allow using
+ * huge pages for the memory
*
* Return: pointer to the allocated memory or %NULL on error
*/
-void *vmalloc_no_huge(unsigned long size)
+void *vmalloc_huge(unsigned long size, gfp_t gfp_mask)
{
return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
- GFP_KERNEL, PAGE_KERNEL, VM_NO_HUGE_VMAP,
+ gfp_mask, PAGE_KERNEL, VM_ALLOW_HUGE_VMAP,
NUMA_NO_NODE, __builtin_return_address(0));
}
-EXPORT_SYMBOL(vmalloc_no_huge);
+EXPORT_SYMBOL_GPL(vmalloc_huge);
/**
* vzalloc - allocate virtually contiguous memory with zero fill