[PATCH v13 14/14] powerpc/64s/radix: Enable huge vmalloc mappings
From: Nicholas Piggin <npiggin@gmail.com>
Date: 2021-03-17 06:26:35
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. Cc: linuxppc-dev@lists.ozlabs.org Acked-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> --- .../admin-guide/kernel-parameters.txt | 2 ++ arch/powerpc/Kconfig | 1 + arch/powerpc/kernel/module.c | 22 +++++++++++++++---- 3 files changed, 21 insertions(+), 4 deletions(-)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 04545725f187..1f481f904895 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt@@ -3243,6 +3243,8 @@ 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 386ae12d8523..b7cade9566da 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig@@ -181,6 +181,7 @@ config PPC select GENERIC_GETTIMEOFDAY 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_KASAN if PPC32 && PPC_PAGE_SHIFT <= 14 select HAVE_ARCH_KASAN_VMALLOC if PPC32 && PPC_PAGE_SHIFT <= 14
diff --git a/arch/powerpc/kernel/module.c b/arch/powerpc/kernel/module.c
index a211b0253cdb..cdb2d88c54e7 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>
@@ -87,13 +88,26 @@ int module_finalize(const Elf_Ehdr *hdr, return 0; } -#ifdef MODULES_VADDR void *module_alloc(unsigned long size) { + unsigned long start = VMALLOC_START; + unsigned long end = VMALLOC_END; + +#ifdef MODULES_VADDR BUILD_BUG_ON(TASK_SIZE > MODULES_VADDR); + start = MODULES_VADDR; + end = MODULES_END; +#endif + + /* + * 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, MODULES_VADDR, MODULES_END, GFP_KERNEL, - PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS, NUMA_NO_NODE, + return __vmalloc_node_range(size, 1, start, end, GFP_KERNEL, + PAGE_KERNEL_EXEC, + VM_NO_HUGE_VMAP | VM_FLUSH_RESET_PERMS, + NUMA_NO_NODE, __builtin_return_address(0)); } -#endif
--
2.23.0