From: Vadim Fedorenko <vadim.fedorenko@linux.dev>
To: Peter Zijlstra <peterz@infradead.org>
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 06:29:09 -0800 [thread overview]
Message-ID: <bade75b3-92d2-42e8-aede-f7a361b491a9@linux.dev> (raw)
In-Reply-To: <20241119111809.GB2328@noisy.programming.kicks-ass.net>
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..
next prev parent reply other threads:[~2024-11-19 14:29 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 [this message]
2024-11-19 16:17 ` Peter Zijlstra
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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