From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34798) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bQWIa-0005NG-G2 for qemu-devel@nongnu.org; Fri, 22 Jul 2016 04:59:17 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bQWIW-0001Zh-97 for qemu-devel@nongnu.org; Fri, 22 Jul 2016 04:59:11 -0400 Received: from [59.151.112.132] (port=63455 helo=heian.cn.fujitsu.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bQWIV-0001Xz-22 for qemu-devel@nongnu.org; Fri, 22 Jul 2016 04:59:08 -0400 Message-ID: <5791E191.4010404@cn.fujitsu.com> Date: Fri, 22 Jul 2016 17:04:17 +0800 From: Changlong Xie MIME-Version: 1.0 References: <1465568813-19771-1-git-send-email-rth@twiddle.net> <1465568813-19771-16-git-send-email-rth@twiddle.net> In-Reply-To: <1465568813-19771-16-git-send-email-rth@twiddle.net> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 8bit Subject: Re: [Qemu-devel] [PULL 15/15] translate-all: add tb hash bucket info to 'info jit' dump List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Richard Henderson , qemu-devel@nongnu.org, "Emilio G. Cota" Cc: peter.maydell@linaro.org On 06/10/2016 10:26 PM, Richard Henderson wrote: > From: "Emilio G. Cota" > > 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 > Suggested-by: Richard Henderson > Reviewed-by: Richard Henderson > Signed-off-by: Emilio G. Cota > Message-Id: <1465412133-3029-16-git-send-email-cota@braap.org> > Signed-off-by: Richard Henderson > --- > translate-all.c | 36 ++++++++++++++++++++++++++++++++++++ > 1 file changed, 36 insertions(+) > > diff --git a/translate-all.c b/translate-all.c > index b620fcc..e8b88b4 100644 > --- a/translate-all.c > +++ b/translate-all.c > @@ -1668,6 +1668,10 @@ 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; > @@ -1718,6 +1722,38 @@ 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); Hi Emilio If we use kvm accelerator, we will encouter segment fault. slave:~/.xie # gdb --args qemu-colo/x86_64-softmmu/qemu-system-x86_64 --enable-kvm -drive driver=qcow2,file.filename=fd16.qcow2 -monitor stdio -vnc :1 (qemu) info jit Translation buffer state: gen code size 0/0 TB count 0/0 TB avg target size 0 max=0 bytes TB avg host size 0 bytes (expansion ratio: 0.0) cross page TB count 0 (0%) direct jump count 0 (0%) (2 jumps=0 0%) Program received signal SIGSEGV, Segmentation fault. 0x0000555555c0c432 in qht_statistics_init (ht=0x5555561ddfd0 , stats=0x7fffffffcab0) at util/qht.c:786 786 stats->head_buckets = map->n_buckets; Program received signal SIGSEGV, Segmentation fault. 0x0000555555c0c432 in qht_statistics_init (ht=0x5555561ddfd0 , stats=0x7fffffffcab0) at util/qht.c:786 786 stats->head_buckets = map->n_buckets; (gdb) p *ht $1 = {map = 0x0, lock = {lock = {__data = {__lock = 0, __count = 0, __owner = 0, __nusers = 0, __kind = 0, __spins = 0, __list = {__prev = 0x0, __next = 0x0}}, __size = '\000' , __align = 0}}, mode = 0} (gdb) Thanks -Xie > + > + 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", >