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authorSong Liu <song@kernel.org>2022-04-15 09:44:10 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2022-04-19 12:08:57 -0700
commit559089e0a93d44280ec3ab478830af319c56dbe3 (patch)
treeb4480a72841a160200f7ba9d3097d9db1d92cf9c /arch
parentb7f73403a3e922c20bb278ba3cfcc3c61930d82a (diff)
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 'arch')
-rw-r--r--arch/Kconfig6
-rw-r--r--arch/powerpc/kernel/module.c2
-rw-r--r--arch/s390/kvm/pv.c7
3 files changed, 4 insertions, 11 deletions
diff --git a/arch/Kconfig b/arch/Kconfig
index 29b0167c088b..31c4fdc4a4ba 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -854,10 +854,8 @@ config HAVE_ARCH_HUGE_VMAP
#
# Archs that select this would be capable of PMD-sized vmaps (i.e.,
-# arch_vmap_pmd_supported() returns true), and they must make no assumptions
-# that vmalloc memory is mapped with PAGE_SIZE ptes. The VM_NO_HUGE_VMAP flag
-# can be used to prohibit arch-specific allocations from using hugepages to
-# help with this (e.g., modules may require it).
+# arch_vmap_pmd_supported() returns true). The VM_ALLOW_HUGE_VMAP flag
+# must be used to enable allocations to use hugepages.
#
config HAVE_ARCH_HUGE_VMALLOC
depends on HAVE_ARCH_HUGE_VMAP
diff --git a/arch/powerpc/kernel/module.c b/arch/powerpc/kernel/module.c
index 40a583e9d3c7..97a76a8619fb 100644
--- a/arch/powerpc/kernel/module.c
+++ b/arch/powerpc/kernel/module.c
@@ -101,7 +101,7 @@ __module_alloc(unsigned long size, unsigned long start, unsigned long end, bool
* too.
*/
return __vmalloc_node_range(size, 1, start, end, gfp, prot,
- VM_FLUSH_RESET_PERMS | VM_NO_HUGE_VMAP,
+ VM_FLUSH_RESET_PERMS,
NUMA_NO_NODE, __builtin_return_address(0));
}
diff --git a/arch/s390/kvm/pv.c b/arch/s390/kvm/pv.c
index 7f7c0d6af2ce..cc7c9599f43e 100644
--- a/arch/s390/kvm/pv.c
+++ b/arch/s390/kvm/pv.c
@@ -137,12 +137,7 @@ static int kvm_s390_pv_alloc_vm(struct kvm *kvm)
/* Allocate variable storage */
vlen = ALIGN(virt * ((npages * PAGE_SIZE) / HPAGE_SIZE), PAGE_SIZE);
vlen += uv_info.guest_virt_base_stor_len;
- /*
- * The Create Secure Configuration Ultravisor Call does not support
- * using large pages for the virtual memory area.
- * This is a hardware limitation.
- */
- kvm->arch.pv.stor_var = vmalloc_no_huge(vlen);
+ kvm->arch.pv.stor_var = vzalloc(vlen);
if (!kvm->arch.pv.stor_var)
goto out_err;
return 0;