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authorVineet Gupta <vgupta@synopsys.com>2016-09-28 11:53:17 -0700
committerVineet Gupta <vgupta@synopsys.com>2017-11-21 15:21:08 -0800
commit82385732b1c9d6a22942b5fe6e48a99891cb806f (patch)
treecf0c5e5c0ca3f7490eaab51f8346368d24875e9c /arch
parent5b9027d6d044d4917992119d184ab0bb616489cc (diff)
downloadlinux-82385732b1c9d6a22942b5fe6e48a99891cb806f.tar.bz2
ARC: perf: avoid vmalloc backed mmap
For non-alising Dcache, vmalloc is not needed. vmalloc triggers additonal D-TLB Misses in the perf interrupt code path making it slightly inefficient as evident from hackbench runs below. | [ARCLinux]# perf stat -e dTLB-load-misses --repeat 5 hackbench | Running with 10*40 (== 400) tasks. | Time: 35.060 | ... | Performance counter stats for 'hackbench' (5 runs): Before: 399235 dTLB-load-misses ( +- 2.08% ) After : 397676 dTLB-load-misses ( +- 2.27% ) Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/arc/Kconfig2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index c84e67fdea09..f3cad98eeb8f 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -39,7 +39,7 @@ config ARC
select OF
select OF_EARLY_FLATTREE
select OF_RESERVED_MEM
- select PERF_USE_VMALLOC
+ select PERF_USE_VMALLOC if ARC_CACHE_VIPT_ALIASING
select HAVE_DEBUG_STACKOVERFLOW
select HAVE_GENERIC_DMA_COHERENT
select HAVE_KERNEL_GZIP