From: kajoljain Subject: Re: [PATCH v6] tools/perf/metricgroup: Fix printing event names of metric group with multiple events incase of overlapping events Date: Fri, 20 Mar 2020 12:14:36 +0530 Message-ID: References: <20200221101121.28920-1-kjain@linux.ibm.com> <20200318192856.GQ11531@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20200318192856.GQ11531@kernel.org> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Arnaldo Carvalho de Melo Cc: linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Jiri Olsa , Alexander Shishkin , Andi Kleen , Kan Liang , Peter Zijlstra , Jin Yao , Madhavan Srinivasan , Anju T Sudhakar , Ravi Bangoria List-Id: linux-perf-users.vger.kernel.org On 3/19/20 12:58 AM, Arnaldo Carvalho de Melo wrote: > Em Fri, Feb 21, 2020 at 03:41:21PM +0530, Kajol Jain escreveu: >> Commit f01642e4912b ("perf metricgroup: Support multiple >> events for metricgroup") introduced support for multiple events >> in a metric group. But with the current upstream, metric events >> names are not printed properly incase we try to run multiple >> metric groups with overlapping event. >> >> With current upstream version, incase of overlapping metric events >> issue is, we always start our comparision logic from start. >> So, the events which already matched with some metric group also >> take part in comparision logic. Because of that when we have overlapping >> events, we end up matching current metric group event with already matched >> one. >> >> For example, in skylake machine we have metric event CoreIPC and >> Instructions. Both of them need 'inst_retired.any' event value. >> As events in Instructions is subset of events in CoreIPC, they >> endup in pointing to same 'inst_retired.any' value. >> >> In skylake platform: >> >> command:# ./perf stat -M CoreIPC,Instructions -C 0 sleep 1 >> >> Performance counter stats for 'CPU(s) 0': >> >> 1,254,992,790 inst_retired.any # 1254992790.0 >> Instructions >> # 1.3 CoreIPC >> 977,172,805 cycles >> 1,254,992,756 inst_retired.any >> >> 1.000802596 seconds time elapsed >> >> command:# sudo ./perf stat -M UPI,IPC sleep 1 >> >> Performance counter stats for 'sleep 1': >> 948,650 uops_retired.retire_slots >> 866,182 inst_retired.any # 0.7 IPC >> 866,182 inst_retired.any >> 1,175,671 cpu_clk_unhalted.thread >> >> Patch fixes the issue by adding a new bool pointer 'evlist_used' to keep >> track of events which already matched with some group by setting it true. >> So, we skip all used events in list when we start comparision logic. >> Patch also make some changes in comparision logic, incase we get a match >> miss, we discard the whole match and start again with first event id in >> metric event. >> >> With this patch: >> In skylake platform: >> >> command:# ./perf stat -M CoreIPC,Instructions -C 0 sleep 1 >> >> Performance counter stats for 'CPU(s) 0': >> >> 3,348,415 inst_retired.any # 0.3 CoreIPC >> 11,779,026 cycles >> 3,348,381 inst_retired.any # 3348381.0 >> Instructions >> >> 1.001649056 seconds time elapsed >> >> command:# ./perf stat -M UPI,IPC sleep 1 >> >> Performance counter stats for 'sleep 1': >> >> 1,023,148 uops_retired.retire_slots # 1.1 UPI >> 924,976 inst_retired.any >> 924,976 inst_retired.any # 0.6 IPC >> 1,489,414 cpu_clk_unhalted.thread >> >> 1.003064672 seconds time elapsed >> >> Signed-off-by: Kajol Jain >> Acked-by: Jiri Olsa > > This is an area I think needs some improvement, look how it ends up > setting up the inst_retired.any multiple times: > > [root@seventh ~]# perf stat -vv -M CoreIPC,Instructions -C 0 sleep 1 > Using CPUID GenuineIntel-6-9E-9 > metric expr inst_retired.any / cycles for CoreIPC > found event inst_retired.any > found event cycles > metric expr inst_retired.any for Instructions > found event inst_retired.any > adding {inst_retired.any,cycles}:W,{inst_retired.any}:W > intel_pt default config: tsc,mtc,mtc_period=3,psb_period=3,pt,branch > inst_retired.any -> cpu/event=0xc0,(null)=0x1e8483/ > inst_retired.any -> cpu/event=0xc0,(null)=0x1e8483/ > ------------------------------------------------------------ > perf_event_attr: > type 4 > size 120 > config 0xc0 > sample_type IDENTIFIER > read_format TOTAL_TIME_ENABLED|TOTAL_TIME_RUNNING|ID|GROUP > disabled 1 > inherit 1 > exclude_guest 1 > ------------------------------------------------------------ > sys_perf_event_open: pid -1 cpu 0 group_fd -1 flags 0x8 = 3 > ------------------------------------------------------------ > perf_event_attr: > size 120 > sample_type IDENTIFIER > read_format TOTAL_TIME_ENABLED|TOTAL_TIME_RUNNING|ID|GROUP > inherit 1 > exclude_guest 1 > ------------------------------------------------------------ > sys_perf_event_open: pid -1 cpu 0 group_fd 3 flags 0x8 = 4 > ------------------------------------------------------------ > perf_event_attr: > type 4 > size 120 > config 0xc0 > sample_type IDENTIFIER > read_format TOTAL_TIME_ENABLED|TOTAL_TIME_RUNNING > disabled 1 > inherit 1 > exclude_guest 1 > ------------------------------------------------------------ > sys_perf_event_open: pid -1 cpu 0 group_fd -1 flags 0x8 = 5 > inst_retired.any: 0: 507070 1000948076 1000948076 > cycles: 0: 1250258 1000948076 1000948076 > inst_retired.any: 0: 507038 1000953052 1000953052 > inst_retired.any: 507070 1000948076 1000948076 > cycles: 1250258 1000948076 1000948076 > inst_retired.any: 507038 1000953052 1000953052 > > Performance counter stats for 'CPU(s) 0': > > 507,070 inst_retired.any # 0.4 CoreIPC > 1,250,258 cycles > 507,038 inst_retired.any # 507038.0 Instructions > > 1.000964961 seconds time elapsed > > [root@seventh ~]# > > And it ends up printing the "inst_retired.any" multiple times, with > different values, as after all two events were allocated, can't we > notice this and set just one inst_retired.any and then when calculating > the metrics just do something like: > > # perf stat -M CoreIPC,Instructions -C 0 sleep 1 > > Performance counter stats for 'CPU(s) 0': > > 507,070 inst_retired.any # 0.4 CoreIPC, > # 507,070 Instructions > 1,250,258 cycles > > 1.000964961 seconds time elapsed > # > > ? > > Ditto for: > > command:# perf stat -M UPI,IPC sleep 1 > > Performance counter stats for 'sleep 1': > > 1,023,148 uops_retired.retire_slots # 1.1 UPI > 924,976 inst_retired.any > 924,976 inst_retired.any # 0.6 IPC > 1,489,414 cpu_clk_unhalted.thread > > 1.003064672 seconds time elapsed > > Wouldn't this be better as: > > command:# perf stat -M UPI,IPC sleep 1 > > Performance counter stats for 'sleep 1': > > 1,023,148 uops_retired.retire_slots # 1.1 UPI > 924,976 inst_retired.any > 1,489,414 cpu_clk_unhalted.thread # 0.6 IPC > > 1.003064672 seconds time elapsed > > This should help to look at many metrics at the same time by requiring > less counters to be allocated, etc, or am I missing something here? Hi Arnaldo, Yes that will be better. I will look into it from my end. Thanks, Kajol > > Since this went thru multiple versions and Jiri is satisfied with it, > I'm applying the patch, but please consider this suggestion. > > - Arnaldo >