From: Song Liu <songliubraving@fb.com>
To: KP Singh <kpsingh@kernel.org>
Cc: bpf <bpf@vger.kernel.org>, Networking <netdev@vger.kernel.org>,
open list <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@redhat.com>,
"Peter Zijlstra" <peterz@infradead.org>,
Alexei Starovoitov <ast@kernel.org>,
"Daniel Borkmann" <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>,
"John Fastabend" <john.fastabend@gmail.com>,
Kernel Team <Kernel-team@fb.com>, "Hao Luo" <haoluo@google.com>,
kernel test robot <lkp@intel.com>
Subject: Re: [PATCH bpf-next 1/4] bpf: enable task local storage for tracing programs
Date: Mon, 11 Jan 2021 23:16:48 +0000 [thread overview]
Message-ID: <CAA56F7D-0F98-4E36-9684-AE466351C353@fb.com> (raw)
In-Reply-To: <CACYkzJ6BT8F+75GW=7hLwjMwFccYBqPb3FXV5dVk0SkeNFpurg@mail.gmail.com>
> On Jan 11, 2021, at 2:14 AM, KP Singh <kpsingh@kernel.org> wrote:
>
> On Sat, Jan 9, 2021 at 12:35 AM Song Liu <songliubraving@fb.com> wrote:
>>
>> To access per-task data, BPF program typically creates a hash table with
>> pid as the key. This is not ideal because:
>> 1. The use need to estimate requires size of the hash table, with may be
>> inaccurate;
>> 2. Big hash tables are slow;
>> 3. To clean up the data properly during task terminations, the user need
>> to write code.
>>
>> Task local storage overcomes these issues and becomes a better option for
>> these per-task data. Task local storage is only available to BPF_LSM. Now
>> enable it for tracing programs.
>
> Also mention here that you change the pointer from being a security blob to a
> dedicated member in the task struct. I assume this is because you want to
> use it without CONFIG_BPF_LSM?
Yes, exactly. I will add this to the commit log.
>
>>
>
> Can you also mention the reasons for changing the
> raw_spin_lock_bh to raw_spin_lock_irqsave in the commit log?
This is because we will use these in irq context. I will add this to the
commit log.
Thanks,
Song
next prev parent reply other threads:[~2021-01-12 0:30 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20210108231950.3844417-1-songliubraving@fb.com>
[not found] ` <20210108231950.3844417-2-songliubraving@fb.com>
2021-01-11 6:27 ` [PATCH bpf-next 1/4] bpf: enable task local storage for tracing programs Yonghong Song
2021-01-11 10:17 ` KP Singh
2021-01-11 15:56 ` Yonghong Song
2021-01-11 10:14 ` KP Singh
2021-01-11 23:16 ` Song Liu [this message]
2021-01-11 17:16 ` Yonghong Song
2021-01-11 18:56 ` Martin KaFai Lau
2021-01-11 21:35 ` KP Singh
2021-01-11 21:58 ` Martin KaFai Lau
2021-01-11 23:45 ` Song Liu
2021-01-12 16:32 ` Yonghong Song
2021-01-12 16:53 ` KP Singh
2021-01-15 23:34 ` Song Liu
2021-01-16 0:55 ` Yonghong Song
2021-01-16 1:12 ` Song Liu
2021-01-16 1:50 ` Yonghong Song
2021-01-11 23:41 ` Song Liu
2021-01-12 18:21 ` Martin KaFai Lau
[not found] ` <20210108231950.3844417-4-songliubraving@fb.com>
2021-01-11 17:37 ` [PATCH bpf-next 3/4] bpf: runqslower: prefer use local vmlinux Yonghong Song
[not found] ` <20210108231950.3844417-5-songliubraving@fb.com>
2021-01-11 17:49 ` [PATCH bpf-next 4/4] bpf: runqslower: use task local storage Yonghong Song
2021-01-11 22:54 ` Song Liu
2021-01-12 3:24 ` Yonghong Song
2021-01-12 7:14 ` Andrii Nakryiko
2021-01-12 7:33 ` Yonghong Song
[not found] ` <20210108231950.3844417-3-songliubraving@fb.com>
2021-01-11 17:30 ` [PATCH bpf-next 2/4] selftests/bpf: add non-BPF_LSM test for " Yonghong Song
2021-01-11 17:44 ` KP Singh
2021-01-11 22:50 ` Song Liu
2021-01-11 22:49 ` Song Liu
2021-01-12 7:06 ` Andrii Nakryiko
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