On 25/05/16 04:13, Emilio G. Cota wrote:
> 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]
I personally don't see much use of the histogram labels. However,
Acked-by: Sergey Fedorov <sergey.fedo...@linaro.org>
>
> Suggested-by: Richard Henderson <r...@twiddle.net>
> Reviewed-by: Richard Henderson <r...@twiddle.net>
> Signed-off-by: Emilio G. Cota <c...@braap.org>
> ---
> translate-all.c | 36 ++++++++++++++++++++++++++++++++++++
> 1 file changed, 36 insertions(+)
>
> diff --git a/translate-all.c b/translate-all.c
> index 5357737..c8074cf 100644
> --- a/translate-all.c
> +++ b/translate-all.c
> @@ -1667,6 +1667,10 @@ void dump_exec_info(FILE *f, fprintf_function
> cpu_fprintf)
> int i, target_code_size, max_target_code_size;
> int direct_jmp_count, direct_jmp2_count, cross_page;
> TranslationBlock *tb;
> + struct qht_stats hst;
> + uint32_t hgram_opts;
> + size_t hgram_bins;
> + char *hgram;
>
> target_code_size = 0;
> max_target_code_size = 0;
> @@ -1717,6 +1721,38 @@ void dump_exec_info(FILE *f, fprintf_function
> cpu_fprintf)
> direct_jmp2_count,
> tcg_ctx.tb_ctx.nb_tbs ? (direct_jmp2_count * 100) /
> tcg_ctx.tb_ctx.nb_tbs : 0);
> +
> + qht_statistics_init(&tcg_ctx.tb_ctx.htable, &hst);
> +
> + cpu_fprintf(f, "TB hash buckets %zu/%zu (%0.2f%% head buckets
> used)\n",
> + hst.used_head_buckets, hst.head_buckets,
> + (double)hst.used_head_buckets / hst.head_buckets * 100);
> +
> + hgram_opts = QDIST_PR_BORDER | QDIST_PR_LABELS;
> + hgram_opts |= QDIST_PR_100X | QDIST_PR_PERCENT;
> + if (qdist_xmax(&hst.occupancy) - qdist_xmin(&hst.occupancy) == 1) {
> + hgram_opts |= QDIST_PR_NODECIMAL;
> + }
> + hgram = qdist_pr(&hst.occupancy, 10, hgram_opts);
> + cpu_fprintf(f, "TB hash occupancy %0.2f%% avg chain occ. Histogram:
> %s\n",
> + qdist_avg(&hst.occupancy) * 100, hgram);
> + g_free(hgram);
> +
> + hgram_opts = QDIST_PR_BORDER | QDIST_PR_LABELS;
> + hgram_bins = qdist_xmax(&hst.chain) - qdist_xmin(&hst.chain);
> + if (hgram_bins > 10) {
> + hgram_bins = 10;
> + } else {
> + hgram_bins = 0;
> + hgram_opts |= QDIST_PR_NODECIMAL | QDIST_PR_NOBINRANGE;
> + }
> + hgram = qdist_pr(&hst.chain, hgram_bins, hgram_opts);
> + cpu_fprintf(f, "TB hash avg chain %0.3f buckets. Histogram: %s\n",
> + qdist_avg(&hst.chain), hgram);
> + g_free(hgram);
> +
> + qht_statistics_destroy(&hst);
> +
> cpu_fprintf(f, "\nStatistics:\n");
> cpu_fprintf(f, "TB flush count %d\n",
> tcg_ctx.tb_ctx.tb_flush_count);
> cpu_fprintf(f, "TB invalidate count %d\n",
