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Date:   Tue, 8 Jan 2019 12:53:41 -0800
From:   Andi Kleen <ak@linux.intel.com>
To:     Nadav Amit <nadav.amit@gmail.com>
Cc:     Peter Zijlstra <peterz@infradead.org>,
        Adrian Hunter <adrian.hunter@intel.com>,
        Ingo Molnar <mingo@redhat.com>,
        Andy Lutomirski <luto@kernel.org>,
        Josh Poimboeuf <jpoimboe@redhat.com>,
        Edward Cree <ecree@solarflare.com>,
        "H . Peter Anvin" <hpa@zytor.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        LKML <linux-kernel@vger.kernel.org>, X86 ML <x86@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Borislav Petkov <bp@alien8.de>,
        David Woodhouse <dwmw@amazon.co.uk>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        songliubraving@fb.com
Subject: Re: [RFC v2 0/6] x86: dynamic indirect branch promotion
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> BTW: I am not sure that static-keys are much better. Their change also
> affects the control flow, and they do affect the control flow.

Static keys have the same problem, but they only change infrequently so usually
it's not too big a problem if you dump the kernel close to the tracing 
sessions.

simple-pt doesn't have a similar mechanism, so it suffers more from it.

-Andi