This caused delay i guess

[    0.869560] Testing concurrent rhashtable access from 10 threads
[    2.009731] Started 10 threads, 0 failed
[    2.012554] test passed
[    2.012985] test_printf: all 256 tests passed
[    2.095763] test_bitmap: test 13: input is '0-2047:128/256' OK, Time: 1
[    2.100869] test_bitmap: all 460506 tests passed
[    2.100891] test_uuid: all 18 tests passed
[    2.101145] atomic64_test: passed
[    2.101209] rbtree testing
[    3.790082]  -> test 1 (latency of nnodes insert+delete): 20 cycles
[    5.721718]  -> test 2 (latency of nnodes cached insert+delete): 23 cycles
[    5.999294]  -> test 3 (latency of inorder traversal): 3 cycles
[    6.002725]  -> test 4 (latency to fetch first node)
[    6.002735]         non-cached: 0 cycles
[    6.002745]         cached: 0 cycles
[    6.128704] augmented rbtree testing
[    8.776127]  -> test 1 (latency of nnodes insert+delete): 31 cycles
[   11.618868]  -> test 2 (latency of nnodes cached insert+delete): 34 cycles
[   11.786264] interval tree insert/remove
[   14.614041]  -> 33 cycles
[   14.614056] interval tree search
[   16.203825]  -> 190 cycles (2692 results)