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Date:   Fri, 21 Feb 2020 14:15:32 -0800
From:   Kees Cook <keescook@chromium.org>
To:     Thomas Gleixner <tglx@linutronix.de>
Cc:     Vinicius Costa Gomes <vinicius.gomes@intel.com>,
        LKML <linux-kernel@vger.kernel.org>,
        David Miller <davem@davemloft.net>, bpf@vger.kernel.org,
        netdev@vger.kernel.org, Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Sebastian Sewior <bigeasy@linutronix.de>,
        Peter Zijlstra <peterz@infradead.org>,
        Clark Williams <williams@redhat.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Juri Lelli <juri.lelli@redhat.com>,
        Ingo Molnar <mingo@kernel.org>, Will Drewry <wad@chromium.org>,
        Andy Lutomirski <luto@kernel.org>
Subject: Re: [RFC patch 09/19] bpf: Use BPF_PROG_RUN_PIN_ON_CPU() at simple
 call sites.
Message-ID: <202002211415.4111F356A@keescook>
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 <875zg3q7cn.fsf@nanos.tec.linutronix.de>
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On Fri, Feb 21, 2020 at 03:00:54PM +0100, Thomas Gleixner wrote:
> Kees Cook <keescook@chromium.org> writes:
> > They're technically independent, but they are related to each
> > other. (i.e. order matters, process hierarchy matters, etc). There's no
> > reason I can see that we can't switch CPUs between running them, though.
> > (AIUI, nothing here would suddenly make these run in parallel, right?)
> 
> Of course not. If we'd run the same thread on multiple CPUs in parallel
> the ordering of your BPF programs would be the least of your worries.

Right, okay, good. I just wanted to be extra sure. :)

-- 
Kees Cook