Le 03/05/2021 à 11:17, Nicholas Piggin a écrit :
This reduces TLB misses by nearly 30x on a `git diff` workload on a
2-node POWER9 (59,800 -> 2,100) and reduces CPU cycles by 0.54%, due
to vfs hashes being allocated with 2MB pages.
Acked-by: Michael Ellerman <m...@ellerman.id.au>
Signed-off-by: Nicholas Piggin <npig...@gmail.com>
Reviewed-by: Christophe Leroy <christophe.le...@csgroup.eu>
---
Since v2:
- Fix ppc32 compile bug.
Since v1:
- Don't define MODULES_VADDR which has some other side effect (e.g.,
ptdump).
- Fixed (hopefully) kbuild warning.
- Keep __vmalloc_node_range call on 3 lines.
.../admin-guide/kernel-parameters.txt | 2 ++
arch/powerpc/Kconfig | 1 +
arch/powerpc/kernel/module.c | 18 +++++++++++++-----
3 files changed, 16 insertions(+), 5 deletions(-)
diff --git a/Documentation/admin-guide/kernel-parameters.txt
b/Documentation/admin-guide/kernel-parameters.txt
index 1c0a3cf6fcc9..1be38b25c485 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -3250,6 +3250,8 @@
nohugeiomap [KNL,X86,PPC,ARM64] Disable kernel huge I/O mappings.
+ nohugevmalloc [PPC] Disable kernel huge vmalloc mappings.
+
nosmt [KNL,S390] Disable symmetric multithreading (SMT).
Equivalent to smt=1.
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 1e6230bea09d..c547a9d6a2dd 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -185,6 +185,7 @@ config PPC
select GENERIC_VDSO_TIME_NS
select HAVE_ARCH_AUDITSYSCALL
select HAVE_ARCH_HUGE_VMAP if PPC_BOOK3S_64 &&
PPC_RADIX_MMU
+ select HAVE_ARCH_HUGE_VMALLOC if HAVE_ARCH_HUGE_VMAP
select HAVE_ARCH_JUMP_LABEL
select HAVE_ARCH_JUMP_LABEL_RELATIVE
select HAVE_ARCH_KASAN if PPC32 && PPC_PAGE_SHIFT <= 14
diff --git a/arch/powerpc/kernel/module.c b/arch/powerpc/kernel/module.c
index fab84024650c..3f35c8d20be7 100644
--- a/arch/powerpc/kernel/module.c
+++ b/arch/powerpc/kernel/module.c
@@ -8,6 +8,7 @@
#include <linux/moduleloader.h>
#include <linux/err.h>
#include <linux/vmalloc.h>
+#include <linux/mm.h>
#include <linux/bug.h>
#include <asm/module.h>
#include <linux/uaccess.h>
@@ -88,17 +89,22 @@ int module_finalize(const Elf_Ehdr *hdr,
return 0;
}
-#ifdef MODULES_VADDR
static __always_inline void *
__module_alloc(unsigned long size, unsigned long start, unsigned long end)
{
- return __vmalloc_node_range(size, 1, start, end, GFP_KERNEL,
- PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS,
NUMA_NO_NODE,
- __builtin_return_address(0));
+ /*
+ * Don't do huge page allocations for modules yet until more testing
+ * is done. STRICT_MODULE_RWX may require extra work to support this
+ * too.
+ */
+ return __vmalloc_node_range(size, 1, start, end, GFP_KERNEL,
PAGE_KERNEL_EXEC,
+ VM_FLUSH_RESET_PERMS | VM_NO_HUGE_VMAP,
+ NUMA_NO_NODE, __builtin_return_address(0));
}
void *module_alloc(unsigned long size)
{
+#ifdef MODULES_VADDR
unsigned long limit = (unsigned long)_etext - SZ_32M;
void *ptr = NULL;
@@ -112,5 +118,7 @@ void *module_alloc(unsigned long size)
ptr = __module_alloc(size, MODULES_VADDR, MODULES_END);
return ptr;
-}
+#else
+ return __module_alloc(size, VMALLOC_START, VMALLOC_END);
#endif
+}
