From: Roman Gushchin <guro@fb.com>
To: Huichun Feng <foxhoundsk.tw@gmail.com>
Cc: <bpf@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
<mgorman@techsingularity.net>, <mingo@redhat.com>,
<peterz@infradead.org>
Subject: Re: [PATCH rfc 0/6] Scheduler BPF
Date: Tue, 18 Jan 2022 14:54:24 -0800 [thread overview]
Message-ID: <YedFIIK+a7AbsfPt@carbon.dhcp.thefacebook.com> (raw)
In-Reply-To: <20220115082924.4123401-1-foxhoundsk.tw@gmail.com>
On Sat, Jan 15, 2022 at 04:29:24PM +0800, Huichun Feng wrote:
> Hi Roman and the list,
Hello Huichun!
>
> I have a naive question regarding BPF hook for sched.
>
> Given that BPF can also be attached to tracepoint, why do we add a BPF prog
> type specific to sched?
Tracing programs can have return values as well, see kretprobes.
>
> The reason I can come up with is that sched BPF can have retval to drive the
> scheduling decision in static branch, whereas tracepoint is not able to do this.
> Is it mainly because of this or anything else?
Well, you are right that right now there is no strict necessity to
introduce a new prog type (aside from static branch mechanism you
mentioned), however I believe it's useful in a long run. Sched
programs might be able to use a different set of helpers, maybe there
will be some additional restrictions, etc. It's an RFC version of the
patchset and any ideas, suggestions and critic are highly welcome!
Thanks!
next prev parent reply other threads:[~2022-01-18 22:54 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20210915213550.3696532-1-guro@fb.com>
2021-09-16 0:19 ` [PATCH rfc 0/6] Scheduler BPF Hao Luo
2021-09-16 1:42 ` Roman Gushchin
2021-09-16 16:24 ` Roman Gushchin
2021-09-16 16:24 ` [PATCH rfc 1/6] bpf: sched: basic infrastructure for scheduler bpf Roman Gushchin
2021-09-16 16:24 ` [PATCH rfc 2/6] bpf: sched: add convenient helpers to identify sched entities Roman Gushchin
2021-11-25 6:09 ` Yafang Shao
2021-11-26 19:50 ` Roman Gushchin
2021-09-16 16:24 ` [PATCH rfc 3/6] bpf: sched: introduce bpf_sched_enable() Roman Gushchin
2021-09-16 16:24 ` [PATCH rfc 4/6] sched: cfs: add bpf hooks to control wakeup and tick preemption Roman Gushchin
2021-10-01 3:35 ` Barry Song
2021-10-02 0:13 ` Roman Gushchin
2021-09-16 16:24 ` [PATCH rfc 5/6] libbpf: add support for scheduler bpf programs Roman Gushchin
2021-09-16 16:24 ` [PATCH rfc 6/6] bpftool: recognize scheduler programs Roman Gushchin
2021-09-16 16:36 ` [PATCH rfc 0/6] Scheduler BPF Roman Gushchin
2021-10-06 16:39 ` Qais Yousef
2021-10-06 18:50 ` Roman Gushchin
2021-10-11 16:38 ` Qais Yousef
2021-10-11 18:09 ` Roman Gushchin
2021-10-12 10:16 ` Qais Yousef
[not found] ` <52EC1E80-4C89-43AD-8A59-8ACA184EAE53@gmail.com>
2021-11-25 6:00 ` Yafang Shao
2021-11-26 19:46 ` Roman Gushchin
2022-01-15 8:29 ` Huichun Feng
2022-01-18 22:54 ` Roman Gushchin [this message]
2022-07-19 13:05 ` Ren Zhijie
2022-07-19 13:17 ` Ren Zhijie
2022-07-19 23:21 ` Roman Gushchin
2021-11-20 16:41 Hui-Chun Feng
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