Date: Fri, 1 May 2015 11:03:53 +0200
From: Borislav Petkov <bp@alien8.de>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
        Andy Lutomirski <luto@amacapital.net>,
        Andy Lutomirski <luto@kernel.org>, X86 ML <x86@kernel.org>,
        Denys Vlasenko <vda.linux@googlemail.com>,
        Brian Gerst <brgerst@gmail.com>, Denys Vlasenko <dvlasenk@redhat.com>,
        Ingo Molnar <mingo@kernel.org>, Steven Rostedt <rostedt@goodmis.org>,
        Oleg Nesterov <oleg@redhat.com>,
        Frederic Weisbecker <fweisbec@gmail.com>,
        Alexei Starovoitov <ast@plumgrid.com>, Will Drewry <wad@chromium.org>,
        Kees Cook <keescook@chromium.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Mel Gorman <mgorman@suse.com>
Subject: Re: [PATCH] x86_64, asm: Work around AMD SYSRET SS descriptor
 attribute issue
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 <20150428155511.GF19025@pd.tnic>
 <CA+55aFykHb8oyZquBq53MowOLzc5XXtNW4tad+4cTbO0YYFYNQ@mail.gmail.com>
 <20150428165807.GI19025@pd.tnic>
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On Thu, Apr 30, 2015 at 04:23:26PM -0700, H. Peter Anvin wrote:
> I probably should have added that the microbenchmark specifically tests
> for an atomic 5-byte NOP (as required by tracepoints etc.)  If the
> requirement for 5-byte atomic is dropped there might be faster
> combinations, e.g. 66 66 66 90 might work better on some platforms, or
> using very long 0F 1F sequences.

Right, so I was thinking of extending it for all sizes 1 - 15 and then
run it on boxes. I'll keep you posted.

Thanks for the toy - now I get to have some fun. :-)

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.
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