Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
MIME-Version: 1.0
References: <20210225234319.336131-1-songliubraving@fb.com> <20210226000344.a6aud7aaimrc6wzt@kafai-mbp.dhcp.thefacebook.com>
In-Reply-To: <20210226000344.a6aud7aaimrc6wzt@kafai-mbp.dhcp.thefacebook.com>
From:   Alexei Starovoitov <alexei.starovoitov@gmail.com>
Date:   Fri, 26 Feb 2021 12:03:43 -0800
Message-ID: <CAADnVQKofEPSABz-+WQ65XTcOEQPke08Nity2Mo7-bD2gopVpg@mail.gmail.com>
Subject: Re: [PATCH v6 bpf-next 0/6] bpf: enable task local storage for
 tracing programs
To:     Martin KaFai Lau <kafai@fb.com>
Cc:     Song Liu <songliubraving@fb.com>, bpf <bpf@vger.kernel.org>,
        Network Development <netdev@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Kernel Team <kernel-team@fb.com>,
        Peter Zijlstra <peterz@infradead.org>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Thu, Feb 25, 2021 at 4:04 PM Martin KaFai Lau <kafai@fb.com> wrote:
>
> On Thu, Feb 25, 2021 at 03:43:13PM -0800, Song Liu wrote:
> > This set enables task local storage for non-BPF_LSM programs.
> >
> > It is common for tracing BPF program to access per-task data. Currently,
> > these data are stored in hash tables with pid as the key. In
> > bcc/libbpftools [1], 9 out of 23 tools use such hash tables. However,
> > hash table is not ideal for many use case. Task local storage provides
> > better usability and performance for BPF programs. Please refer to 6/6 for
> > some performance comparison of task local storage vs. hash table.
> Thanks for the patches.
>
> Acked-by: Martin KaFai Lau <kafai@fb.com>

Applied. Thanks.

9 out of 23 libbpf-tools will significantly reduce the tracing overhead. Hooray!