From: Yonghong Song <yonghong.song@linux.dev>
To: Andrii Nakryiko <andrii@kernel.org>,
bpf@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net,
martin.lau@kernel.org
Cc: kernel-team@meta.com
Subject: Re: [PATCH v3 bpf-next 1/2] bpf: make bpf_get_branch_snapshot() architecture-agnostic
Date: Thu, 4 Apr 2024 10:25:40 -0700 [thread overview]
Message-ID: <4ac94d18-082d-4725-9600-0e0a7ccd39cb@linux.dev> (raw)
In-Reply-To: <20240404002640.1774210-2-andrii@kernel.org>
On 4/3/24 5:26 PM, Andrii Nakryiko wrote:
> perf_snapshot_branch_stack is set up in an architecture-agnostic way, so
> there is no reason for BPF subsystem to keep track of which
> architectures do support LBR or not. E.g., it looks like ARM64 might soon
> get support for BRBE ([0]), which (with proper integration) should be
> possible to utilize using this BPF helper.
>
> perf_snapshot_branch_stack static call will point to
> __static_call_return0() by default, which just returns zero, which will
> lead to -ENOENT, as expected. So no need to guard anything here.
>
> [0] https://lore.kernel.org/linux-arm-kernel/20240125094119.2542332-1-anshuman.khandual@arm.com/
>
> Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
next prev parent reply other threads:[~2024-04-04 17:25 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-04 0:26 [PATCH v3 bpf-next 0/2] Inline bpf_get_branch_snapshot() BPF helper Andrii Nakryiko
2024-04-04 0:26 ` [PATCH v3 bpf-next 1/2] bpf: make bpf_get_branch_snapshot() architecture-agnostic Andrii Nakryiko
2024-04-04 17:25 ` Yonghong Song [this message]
2024-04-04 0:26 ` [PATCH v3 bpf-next 2/2] bpf: inline bpf_get_branch_snapshot() helper Andrii Nakryiko
2024-04-04 17:44 ` Yonghong Song
2024-04-04 18:14 ` Alexei Starovoitov
2024-04-04 18:28 ` Yonghong Song
2024-04-04 18:31 ` Alexei Starovoitov
2024-04-04 20:08 ` Andrii Nakryiko
2024-10-23 8:28 ` Shung-Hsi Yu
2024-10-23 16:04 ` Andrii Nakryiko
2024-04-04 20:20 ` [PATCH v3 bpf-next 0/2] Inline bpf_get_branch_snapshot() BPF helper patchwork-bot+netdevbpf
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