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| author | Vineet Gupta <vgupta@synopsys.com> | 2016-09-28 21:53:17 +0300 |
|---|---|---|
| committer | Vineet Gupta <vgupta@synopsys.com> | 2017-11-22 02:21:08 +0300 |
| commit | 82385732b1c9d6a22942b5fe6e48a99891cb806f (patch) | |
| tree | cf0c5e5c0ca3f7490eaab51f8346368d24875e9c | |
| parent | 5b9027d6d044d4917992119d184ab0bb616489cc (diff) | |
| download | linux-82385732b1c9d6a22942b5fe6e48a99891cb806f.tar.xz | |
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>
| -rw-r--r-- | arch/arc/Kconfig | 2 |
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 |