Examples:

- Good hashing, i.e. tb_hash_func5(phys_pc, pc, flags):
TB count            715135/2684354
[...]
TB hash buckets     388775/524288 (74.15% head buckets used)
TB hash occupancy   33.04% avg chain occ. Histogram: [0,10)%|▆ █  ▅▁▃▁▁|[90,100]%
TB hash avg chain   1.017 buckets. Histogram: 1|█▁▁|3

- Not-so-good hashing, i.e. tb_hash_func5(phys_pc, pc, 0):
TB count            712636/2684354
[...]
TB hash buckets     344924/524288 (65.79% head buckets used)
TB hash occupancy   31.64% avg chain occ. Histogram: [0,10)%|█ ▆  ▅▁▃▁▂|[90,100]%
TB hash avg chain   1.047 buckets. Histogram: 1|█▁▁▁|4

- Bad hashing, i.e. tb_hash_func5(phys_pc, 0, 0):
TB count            702818/2684354
[...]
TB hash buckets     112741/524288 (21.50% head buckets used)
TB hash occupancy   10.15% avg chain occ. Histogram: [0,10)%|█ ▁  ▁▁▁▁▁|[90,100]%
TB hash avg chain   2.107 buckets. Histogram: [1.0,10.2)|█▁▁▁▁▁▁▁▁▁|[83.8,93.0]

- Good hashing, but no auto-resize:
TB count            715634/2684354
TB hash buckets     8192/8192 (100.00% head buckets used)
TB hash occupancy   98.30% avg chain occ. Histogram: [95.3,95.8)%|▁▁▃▄▃▄▁▇▁█|[99.5,100.0]%
TB hash avg chain   22.070 buckets. Histogram: [15.0,16.7)|▁▂▅▄█▅▁▁▁▁|[30.3,32.0]

Acked-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Suggested-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-Id: <1465412133-3029-16-git-send-email-cota@braap.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>