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From: Peter Zijlstra <peterz@infradead.org>
To: Vadim Fedorenko <vadfed@meta.com>
Cc: Borislav Petkov <bp@alien8.de>,
	Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Andrii Nakryiko <andrii@kernel.org>,
	Eduard Zingerman <eddyz87@gmail.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Yonghong Song <yonghong.song@linux.dev>,
	Vadim Fedorenko <vadim.fedorenko@linux.dev>,
	Mykola Lysenko <mykolal@fb.com>,
	x86@kernel.org, bpf@vger.kernel.org,
	Martin KaFai Lau <martin.lau@linux.dev>
Subject: Re: [PATCH bpf-next v8 2/4] bpf: add bpf_cpu_time_counter_to_ns helper
Date: Thu, 21 Nov 2024 12:31:04 +0100	[thread overview]
Message-ID: <20241121113104.GF24774@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <20241121000814.3821326-3-vadfed@meta.com>

On Wed, Nov 20, 2024 at 04:08:12PM -0800, Vadim Fedorenko wrote:
> The new helper should be used to convert cycles received by
> bpf_get_cpu_cycle() into nanoseconds.

This is pertinently false, as written here you're looking for a single
reading into a clock value, while that is exactly not what you want.

Please, go write real changelogs

  reply	other threads:[~2024-11-21 11:31 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-11-21  0:08 [PATCH bpf-next v8 0/4] bpf: add cpu cycles kfuncss Vadim Fedorenko
2024-11-21  0:08 ` [PATCH bpf-next v8 1/4] bpf: add bpf_get_cpu_time_counter kfunc Vadim Fedorenko
2024-11-21 11:32   ` Peter Zijlstra
2024-11-21 14:35     ` Vadim Fedorenko
2024-11-21 15:33       ` Peter Zijlstra
2024-11-21 23:51         ` Andrii Nakryiko
2024-11-21 23:55           ` Vadim Fedorenko
2024-11-21  0:08 ` [PATCH bpf-next v8 2/4] bpf: add bpf_cpu_time_counter_to_ns helper Vadim Fedorenko
2024-11-21 11:31   ` Peter Zijlstra [this message]
2024-11-21  0:08 ` [PATCH bpf-next v8 3/4] selftests/bpf: add selftest to check rdtsc jit Vadim Fedorenko
2024-11-21  0:08 ` [PATCH bpf-next v8 4/4] selftests/bpf: add usage example for cpu cycles kfuncs Vadim Fedorenko
2024-11-22 11:34 ` [PATCH bpf-next v8 0/4] bpf: add cpu cycles kfuncss Peter Zijlstra
2024-11-22 15:40   ` Vadim Fedorenko
2024-11-26 18:12   ` Andrii Nakryiko
2024-11-28 11:27     ` Peter Zijlstra
2024-11-28 11:33       ` Peter Zijlstra
2024-11-28 14:30         ` Vadim Fedorenko
2024-11-28 14:28       ` Vadim Fedorenko
2024-12-02 19:15       ` Andrii Nakryiko

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