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% ) Signed-off-by: Vineet Gupta <[email protected]> --- arch/arc/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) 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 -- 2.7.4
