Date: Thu, 23 Jul 2015 19:08:11 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Jason Baron <jasonbaron0@gmail.com>, Borislav Petkov <bp@alien8.de>,
        Andy Lutomirski <luto@amacapital.net>,
        Thomas Gleixner <tglx@linutronix.de>,
        Mikulas Patocka <mpatocka@redhat.com>,
        Paul Mackerras <paulus@samba.org>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Kees Cook <keescook@chromium.org>,
        Andrea Arcangeli <aarcange@redhat.com>,
        Vince Weaver <vince@deater.net>, "hillf.zj" <hillf.zj@alibaba-inc.com>,
        Valdis Kletnieks <Valdis.Kletnieks@vt.edu>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: Kernel broken on processors without performance counters
Message-ID: <20150723170811.GJ25159@twins.programming.kicks-ass.net>
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 <20150721161215.GU19282@twins.programming.kicks-ass.net>
 <20150721181553.GA3378@nazgul.tnic>
 <55AE9471.1000601@gmail.com>
 <20150722042403.GA6345@nazgul.tnic>
 <55AFCDA4.5010406@gmail.com>
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On Thu, Jul 23, 2015 at 11:34:50AM -0400, Steven Rostedt wrote:
> On Thu, 23 Jul 2015 12:42:15 +0200
> Peter Zijlstra <peterz@infradead.org> wrote:
> 
> > static __always_inline bool arch_static_branch_jump(struct static_key *key, bool inv)
> > {
> > 	if (!inv) {
> > 		asm_volatile_goto("1:"
> > 			"jmp %l[l_yes]\n\t"
> 
> And what happens when this gets converted to a two byte jump?
> 

That would be bad, how can we force it to emit 5 bytes?
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