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From: Martin KaFai Lau <martin.lau@linux.dev>
To: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>,
	Yonghong Song <yhs@meta.com>,
	bpf@vger.kernel.org, Alexei Starovoitov <ast@kernel.org>,
	Andrii Nakryiko <andrii@kernel.org>, Yonghong Song <yhs@fb.com>,
	John Fastabend <john.fastabend@gmail.com>,
	KP Singh <kpsingh@kernel.org>,
	Stanislav Fomichev <sdf@google.com>, Hao Luo <haoluo@google.com>,
	Jiri Olsa <jolsa@kernel.org>, Hou Tao <houtao1@huawei.com>,
	Song Liu <song@kernel.org>
Subject: Re: [bpf-next v2 1/2] bpf: add runtime stats, max cost
Date: Mon, 19 Dec 2022 10:24:07 -0800	[thread overview]
Message-ID: <38a93791-97f1-2fe1-ba1a-04dde1980d85@linux.dev> (raw)
In-Reply-To: <CAPhsuW4ai+ojXTfgfUa+ZXyEfv8siW8Ya9+_oa+Urw=ga+rHKw@mail.gmail.com>

On 12/19/22 12:04 AM, Song Liu wrote:
> While max time cost might be useful in some debugging, I don't think
> we should add it with kernel.bpf_stats_enabled. Otherwise, we can
> argue p50/p90/p99 are also useful in some cases, and some other
> metrics are useful in some other cases.  These metrics together will
> make kernel.bpf_stats_enabled too expensive for the use case above.
> 
> Since the use case is for debugging, have you considered using
> some other BPF programs to profile the target BPF program?
> Please refer to "bpftool prog profile" or "perf stat -b " for
> examples of similar solutions.
+1.  Please consider other suggested solutions that the same can be done in a 
more flexible way.


      reply	other threads:[~2022-12-19 18:24 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-12-15  4:32 [bpf-next v2 1/2] bpf: add runtime stats, max cost xiangxia.m.yue
2022-12-15  4:32 ` [bpf-next v2 2/2] bpftool: " xiangxia.m.yue
2022-12-16  5:39 ` [bpf-next v2 1/2] bpf: " Yonghong Song
2022-12-16  9:05   ` Tonghao Zhang
2022-12-16 16:06     ` Daniel Borkmann
2022-12-17 15:37       ` Tonghao Zhang
2022-12-19  8:04         ` Song Liu
2022-12-19 18:24           ` Martin KaFai Lau [this message]

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