diff options
| author | Nicholas Piggin <npiggin@gmail.com> | 2023-02-03 17:18:37 +1000 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-03-28 16:20:08 -0700 |
| commit | 77f68ebeee201e8960944863c03bd7ac613ca7ed (patch) | |
| tree | 8cc1ee231e70ed5b0c49accc7722e075ac8be48a | |
| parent | 2655421ae69fa479df1575cb2630af9131d28939 (diff) | |
| download | linux-rpi-77f68ebeee201e8960944863c03bd7ac613ca7ed.tar.gz linux-rpi-77f68ebeee201e8960944863c03bd7ac613ca7ed.tar.bz2 linux-rpi-77f68ebeee201e8960944863c03bd7ac613ca7ed.zip | |
powerpc/64s: enable MMU_LAZY_TLB_SHOOTDOWN
On a 16-socket 192-core POWER8 system, the context_switch1_threads
benchmark from will-it-scale (see earlier changelog), upstream can achieve
a rate of about 1 million context switches per second, due to contention
on the mm refcount.
64s meets the prerequisites for CONFIG_MMU_LAZY_TLB_SHOOTDOWN, so enable
the option. This increases the above benchmark to 118 million context
switches per second.
This generates 314 additional IPI interrupts on a 144 CPU system doing a
kernel compile, which is in the noise in terms of kernel cycles.
Link: https://lkml.kernel.org/r/20230203071837.1136453-6-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | arch/powerpc/Kconfig | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index a6c4407d3ec8..49c6d36b2b3e 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -266,6 +266,7 @@ config PPC select MMU_GATHER_PAGE_SIZE select MMU_GATHER_RCU_TABLE_FREE select MMU_GATHER_MERGE_VMAS + select MMU_LAZY_TLB_SHOOTDOWN if PPC_BOOK3S_64 select MODULES_USE_ELF_RELA select NEED_DMA_MAP_STATE if PPC64 || NOT_COHERENT_CACHE select NEED_PER_CPU_EMBED_FIRST_CHUNK if PPC64 |