Re: [QUESTION]perf stat: comment of miss ratio

From: Qi Liu <liuqi115@hisilicon.com>
To: Andi Kleen <ak@linux.intel.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"Peter Zijlstra" <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	"Arnaldo Carvalho de Melo" <acme@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>,
	Jin Yao <yao.jin@linux.intel.com>,
	Ravi Bangoria <ravi.bangoria@linux.ibm.com>,
	Davidlohr Bueso <dave@stgolabs.net>,
	Zhangshaokun <zhangshaokun@hisilicon.com>,
	huangdaode <huangdaode@hisilicon.com>,
	linyunsheng <linyunsheng@huawei.com>,
	John Garry <john.garry@huawei.com>
Subject: Re: [QUESTION]perf stat: comment of miss ratio
Date: Sat, 9 Nov 2019 11:19:30 +0800	[thread overview]
Message-ID: <b7e93eb7-2ef9-1448-c4ca-7495bc934b32@hisilicon.com> (raw)
In-Reply-To: <20191109024754.GA573472@tassilo.jf.intel.com>

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