netdev - Re: [PATCH bpf-next 3/4] bpf: Don't do preempt check when migrate is disabled

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Message-ID: <CALOAHbDdj72pVsaohbj=JCsryiHFQYaia78OP5kO65OSYTVb5A@mail.gmail.com>
Date:   Sat, 2 Jul 2022 10:34:17 +0800
From:   Yafang Shao <laoar.shao@...il.com>
To:     Hao Luo <haoluo@...gle.com>
Cc:     Alexei Starovoitov <ast@...nel.org>,
        Daniel Borkmann <daniel@...earbox.net>,
        Andrii Nakryiko <andrii@...nel.org>, Martin Lau <kafai@...com>,
        Song Liu <songliubraving@...com>, Yonghong Song <yhs@...com>,
        john fastabend <john.fastabend@...il.com>,
        KP Singh <kpsingh@...nel.org>,
        Quentin Monnet <quentin@...valent.com>,
        netdev <netdev@...r.kernel.org>, bpf <bpf@...r.kernel.org>
Subject: Re: [PATCH bpf-next 3/4] bpf: Don't do preempt check when migrate is disabled

On Fri, Jul 1, 2022 at 4:43 AM Hao Luo <haoluo@...gle.com> wrote:
>
> Hi Yafang,
>
> On Wed, Jun 29, 2022 at 8:49 AM Yafang Shao <laoar.shao@...il.com> wrote:
> >
> > It doesn't need to do the preempt check when migrate is disabled
> > after commit
> > 74d862b682f5 ("sched: Make migrate_disable/enable() independent of RT").
> >
> > Signed-off-by: Yafang Shao <laoar.shao@...il.com>
> > ---
>
> In my understanding, migrate_disable() doesn't imply
> preempt_disable(), I think this is not safe. Am I missing something?
>

It seems I have some misunderstanding of it after second thoughts.
I will think more about it.

-- 
Regards
Yafang