* Re: [QUESTION]perf stat: comment of miss ratio
2019-11-09 2:47 ` [QUESTION]perf stat: comment of miss ratio Andi Kleen
@ 2019-11-09 3:19 ` Qi Liu
2019-11-09 18:46 ` Andi Kleen
2019-11-13 10:45 ` John Garry
1 sibling, 1 reply; 4+ messages in thread
From: Qi Liu @ 2019-11-09 3:19 UTC (permalink / raw)
To: Andi Kleen
Cc: linux-kernel, Peter Zijlstra, Ingo Molnar,
Arnaldo Carvalho de Melo, Mark Rutland, Alexander Shishkin,
Jiri Olsa, Namhyung Kim, Jin Yao, Ravi Bangoria, Davidlohr Bueso,
Zhangshaokun, huangdaode, linyunsheng, John Garry
On 2019/11/9 10:47, Andi Kleen wrote:
>> Relevant code is checked to make sure that the ratio is calculated by
>>
>> L1-dcache-load-misses/L1-dcache-loads, data "7.58%=30249/399189*100%" also
>>
>> proves this conclusion.
>>
>> So, I'm not sure why we use "of all L1-dcache hits" here to describe miss
>> ratio,
>
> Yes you're right it should be "of all L1-dcache accesses"
>
> Please send a patch to fix the string and also check if this isn't wrong with some other
> ratio too.
>
> -Andi
>
> .
>
Hi Andi:
Thanks for your reply firstly.
I check the code and find that "of all...hits" is also used to describe miss ratio of
L1-icache, dTLB cache, iTLB cache, LL-cache. Relevant code as follow:
stat-shadow.c:509: out->print_metric(config, out->ctx, color, "%7.2f%%", "of all L1-dcache hits", ratio);
stat-shadow.c:530: out->print_metric(config, out->ctx, color, "%7.2f%%", "of all L1-icache hits", ratio);
stat-shadow.c:550: out->print_metric(config, out->ctx, color, "%7.2f%%", "of all dTLB cache hits", ratio);
stat-shadow.c:570: out->print_metric(config, out->ctx, color, "%7.2f%%", "of all iTLB cache hits", ratio);
stat-shadow.c:590: out->print_metric(config, out->ctx, color, "%7.2f%%", "of all LL-cache hits", ratio);
stat-shadow.c:875: print_metric(config, ctxp, NULL, NULL, "of all L1-dcache hits", 0);
stat-shadow.c:885: print_metric(config, ctxp, NULL, NULL, "of all L1-icache hits", 0);
stat-shadow.c:895: print_metric(config, ctxp, NULL, NULL, "of all dTLB cache hits", 0);
stat-shadow.c:905: print_metric(config, ctxp, NULL, NULL, "of all iTLB cache hits", 0);
stat-shadow.c:915: print_metric(config, ctxp, NULL, NULL, "of all LL-cache hits", 0);
So, may I send a patch to fix all these strings?
Thanks,
liuqi
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [QUESTION]perf stat: comment of miss ratio
2019-11-09 2:47 ` [QUESTION]perf stat: comment of miss ratio Andi Kleen
2019-11-09 3:19 ` Qi Liu
@ 2019-11-13 10:45 ` John Garry
1 sibling, 0 replies; 4+ messages in thread
From: John Garry @ 2019-11-13 10:45 UTC (permalink / raw)
To: Andi Kleen, liuqi (BA)
Cc: linux-kernel, Peter Zijlstra, Ingo Molnar,
Arnaldo Carvalho de Melo, Mark Rutland, Alexander Shishkin,
Jiri Olsa, Namhyung Kim, Jin Yao, Ravi Bangoria, Davidlohr Bueso,
Zhangshaokun, huangdaode, linyunsheng
On 09/11/2019 02:47, Andi Kleen wrote:
>> Relevant code is checked to make sure that the ratio is calculated by
>>
>> L1-dcache-load-misses/L1-dcache-loads, data "7.58%=30249/399189*100%" also
>>
>> proves this conclusion.
>>
>> So, I'm not sure why we use "of all L1-dcache hits" here to describe miss
>> ratio,
>
> Yes you're right it should be "of all L1-dcache accesses"
>
> Please send a patch to fix the string and also check if this isn't wrong with some other
> ratio too.
>
" 399,189 L1-dcache-loads # 246.396 M/sec
30,249 L1-dcache-load-misses # 7.58% of all L1-dcache
hits (18.04%)"
If accesses and loads are equivalent, could we use consistent terminology?
Thanks,
John
^ permalink raw reply [flat|nested] 4+ messages in thread