From: "Aneesh Kumar K.V" <aneesh.kumar at linux.vnet.ibm.com>
Testing with a threaded version of mmap_bench which allocate 1G chunks and
with large number of threads we find:
without patch
32.72% mmap_bench [kernel.vmlinux] [k] do_raw_spin_lock
|
---do_raw_spin_lock
|
--32.68%--0
|
|--15.82%--pte_fragment_alloc
| |
| --15.79%--do_huge_pmd_anonymous_page
| __handle_mm_fault
| handle_mm_fault
| __do_page_fault
| handle_page_fault
| test_mmap
| test_mmap
| start_thread
| __clone
|
|--14.95%--do_huge_pmd_anonymous_page
| __handle_mm_fault
| handle_mm_fault
| __do_page_fault
| handle_page_fault
| test_mmap
| test_mmap
| start_thread
| __clone
|
with patch
12.89% mmap_bench [kernel.vmlinux] [k] do_raw_spin_lock
|
---do_raw_spin_lock
|
--12.83%--0
|
|--3.21%--pagevec_lru_move_fn
| __lru_cache_add
| |
| --2.74%--do_huge_pmd_anonymous_page
| __handle_mm_fault
| handle_mm_fault
| __do_page_fault
| handle_page_fault
| test_mmap
| test_mmap
| start_thread
| __clone
|
|--3.11%--do_huge_pmd_anonymous_page
| __handle_mm_fault
| handle_mm_fault
| __do_page_fault
| handle_page_fault
| test_mmap
| test_mmap
| start_thread
| __clone
.....
|
--0.55%--pte_fragment_alloc
|
--0.55%--do_huge_pmd_anonymous_page
__handle_mm_fault
handle_mm_fault
__do_page_fault
handle_page_fault
test_mmap
test_mmap
start_thread
__clone
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar at linux.vnet.ibm.com>
---
arch/powerpc/platforms/Kconfig.cputype | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index 67d3125d0610..cc892dcfa114 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -292,6 +292,10 @@ config PPC_STD_MMU_32
def_bool y
depends on PPC_STD_MMU && PPC32
+config ARCH_ENABLE_SPLIT_PMD_PTLOCK
+ def_bool y
+ depends on PPC_BOOK3S_64
+
config PPC_RADIX_MMU
bool "Radix MMU Support"
depends on PPC_BOOK3S_64
--
2.14.3