diff options
| author | Paul Burton <paul.burton@imgtec.com> | 2017-06-10 02:26:42 +0200 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2017-06-29 02:42:25 +0200 |
| commit | 25da4e9dedbfa1630cc87903dcced5b249b936ef (patch) | |
| tree | 617710786f89c534be32d4858fa852deaf6b0e01 /arch/mips/Kconfig | |
| parent | MIPS: cmpxchg: Rearrange __xchg() arguments to match xchg() (diff) | |
| download | linux-25da4e9dedbfa1630cc87903dcced5b249b936ef.tar.xz linux-25da4e9dedbfa1630cc87903dcced5b249b936ef.zip | |
MIPS: Use queued read/write locks (qrwlock)
This patch switches MIPS to make use of generically implemented queued
read/write locks, rather than the custom implementation used previously.
This allows us to drop a whole load of inline assembly, share more
generic code, and is also a performance win.
Results from running the AIM7 short workload on a MIPS Creator Ci40 (ie.
2 core 2 thread interAptiv CPU clocked at 546MHz) with v4.12-rc4
pistachio_defconfig, with ftrace disabled due to a current bug, and both
with & without use of queued rwlocks & spinlocks:
Forks | v4.12-rc4 | +qlocks | Change
-------|-----------|----------|--------
10 | 52630.32 | 53316.31 | +1.01%
20 | 51777.80 | 52623.15 | +1.02%
30 | 51645.92 | 52517.26 | +1.02%
40 | 51634.88 | 52419.89 | +1.02%
50 | 51506.75 | 52307.81 | +1.02%
60 | 51500.74 | 52322.72 | +1.02%
70 | 51434.81 | 52288.60 | +1.02%
80 | 51423.22 | 52434.85 | +1.02%
90 | 51428.65 | 52410.10 | +1.02%
The kernels used for these tests also had my "MIPS: Hardcode cpu_has_*
where known at compile time due to ISA" patch applied, which allows the
kernel_uses_llsc checks in cmpxchg() & xchg() to be optimised away at
compile time.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16357/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/Kconfig')
| -rw-r--r-- | arch/mips/Kconfig | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index 9891a1285f25..7c2a64b32179 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -11,6 +11,7 @@ config MIPS select ARCH_SUPPORTS_UPROBES select ARCH_USE_BUILTIN_BSWAP select ARCH_USE_CMPXCHG_LOCKREF if 64BIT + select ARCH_USE_QUEUED_RWLOCKS select ARCH_WANT_IPC_PARSE_VERSION select BUILDTIME_EXTABLE_SORT select CLONE_BACKWARDS |