MIME-Version: 1.0
References: <20210915213550.3696532-1-guro@fb.com> <20210916162451.709260-1-guro@fb.com>
 <52EC1E80-4C89-43AD-8A59-8ACA184EAE53@gmail.com>
In-Reply-To: <52EC1E80-4C89-43AD-8A59-8ACA184EAE53@gmail.com>
From:   Yafang Shao <laoar.shao@gmail.com>
Date:   Thu, 25 Nov 2021 14:00:04 +0800
Message-ID: <CALOAHbC0xNnqWt=og+g=DT0yRqST6cTAUvZkQ-7o8Nw8O-2J9w@mail.gmail.com>
Subject: Re: [PATCH rfc 0/6] Scheduler BPF
To:     Roman Gushchin <guro@fb.com>
Cc:     Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Mel Gorman <mgorman@techsingularity.net>,
        bpf <bpf@vger.kernel.org>, LKML <linux-kernel@vger.kernel.org>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

Hi Roman,

Scheduler BPF is a great idea.
Thanks for the work.

Scheduler BPF won=E2=80=99t be a small feature,  I think we=E2=80=99d bette=
r give a
summary of possible hooks it may add first.
We must have a *basic rule* to control what it will tend to be to
avoid adding BPF hooks here and there.
I haven=E2=80=99t found a clear rule yet, but maybe we can learn it from
netfilter, which has 5 basic hooks.
Regarding the scheduler BPF hooks, some possible basic hooks may be:
  - Hook for Enqueue
  - Hook for Dequeue
  - Hook for Put Prev Task
   - Hook for Set Next Task


> An example of an userspace part, which loads some simple hooks is availab=
le
> here [3]. It's very simple, provided only to simplify playing with the pr=
ovided
> kernel patches.
>

You=E2=80=99d better add this userspace code into samples/bpf/.


[Some error occurs in my mail client, so I resend it]


--
Thanks
Yafang