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Date:   Wed, 3 Mar 2021 14:27:50 +0100
From:   Oleg Nesterov <oleg@redhat.com>
To:     Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc:     Andy Lutomirski <luto@amacapital.net>,
        Andy Lutomirski <luto@kernel.org>, bpf <bpf@vger.kernel.org>,
        Masami Hiramatsu <mhiramat@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>,
        "David S. Miller" <davem@davemloft.net>, X86 ML <x86@kernel.org>,
        Andrew Cooper <andrew.cooper3@citrix.com>
Subject: Re: Why do kprobes and uprobes singlestep?
Message-ID: <20210303132749.GA28955@redhat.com>
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On 03/02, Alexei Starovoitov wrote:
>
> Especially if such tightening will come with performance boost for
> uprobe on a nop and unprobe at the start (which is typically push or
> alu on %sp).
> That would be a great step forward.

Just in case, nop and push are emulated without additional overhead.

Oleg.