From: Peter Zijlstra <peterz@infradead.org>
To: Vadim Fedorenko <vadim.fedorenko@linux.dev>
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>,
Mykola Lysenko <mykolal@fb.com>,
x86@kernel.org, bpf@vger.kernel.org,
Martin KaFai Lau <martin.lau@linux.dev>
Subject: Re: [PATCH bpf-next v7 1/4] bpf: add bpf_get_cpu_cycles kfunc
Date: Tue, 19 Nov 2024 17:17:53 +0100 [thread overview]
Message-ID: <20241119161753.GA28920@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <bade75b3-92d2-42e8-aede-f7a361b491a9@linux.dev>
On Tue, Nov 19, 2024 at 06:29:09AM -0800, Vadim Fedorenko wrote:
> On 19/11/2024 03:18, Peter Zijlstra wrote:
> > On Mon, Nov 18, 2024 at 10:52:42AM -0800, Vadim Fedorenko wrote:
> > > @@ -2094,6 +2094,13 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
> > > if (insn->src_reg == BPF_PSEUDO_KFUNC_CALL) {
> > > int err;
> > > + if (imm32 == BPF_CALL_IMM(bpf_get_cpu_cycles)) {
> > > + if (cpu_feature_enabled(X86_FEATURE_LFENCE_RDTSC))
> > > + EMIT3(0x0F, 0xAE, 0xE8);
> > > + EMIT2(0x0F, 0x31);
> > > + break;
> > > + }
> >
> > TSC != cycles. Naming is bad.
>
> Any suggestions?
>
> JIT for other architectures will come after this one is merged and some
> of them will be using cycles, so not too far away form the truth..
bpf_get_time_stamp() ?
bpf_get_counter() ?
next prev parent reply other threads:[~2024-11-19 16:18 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-11-18 18:52 [PATCH bpf-next v7 0/4] bpf: add cpu cycles kfuncss Vadim Fedorenko
2024-11-18 18:52 ` [PATCH bpf-next v7 1/4] bpf: add bpf_get_cpu_cycles kfunc Vadim Fedorenko
2024-11-19 11:18 ` Peter Zijlstra
2024-11-19 14:29 ` Vadim Fedorenko
2024-11-19 16:17 ` Peter Zijlstra [this message]
2024-11-19 18:03 ` Vadim Fedorenko
2024-11-19 19:16 ` Andrii Nakryiko
2024-11-19 19:27 ` Vadim Fedorenko
2024-11-18 18:52 ` [PATCH bpf-next v7 2/4] bpf: add bpf_cpu_cycles_to_ns helper Vadim Fedorenko
2024-11-19 11:28 ` Peter Zijlstra
2024-11-19 14:38 ` Vadim Fedorenko
2024-11-20 8:49 ` Peter Zijlstra
2024-11-20 13:39 ` Vadim Fedorenko
2024-11-18 18:52 ` [PATCH bpf-next v7 3/4] selftests/bpf: add selftest to check rdtsc jit Vadim Fedorenko
2024-11-18 18:52 ` [PATCH bpf-next v7 4/4] selftests/bpf: add usage example for cpu cycles kfuncs Vadim Fedorenko
2024-11-19 11:47 ` Peter Zijlstra
2024-11-19 14:45 ` Vadim Fedorenko
2024-11-20 8:51 ` Peter Zijlstra
2024-11-20 17:19 ` Vadim Fedorenko
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