From: Jeremy Fitzhardinge <jeremy@goop.org>
Subject: Re: [PATCH RFC V2 3/5] jump_label: if a key has already been initialized,
 don't nop it out
Date: Thu, 06 Oct 2011 14:42:37 -0700
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To: Steven Rostedt <rostedt@goodmis.org>
Cc: Richard Henderson <rth@redhat.com>, Jason Baron <jbaron@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>, "David S. Miller" <davem@davemloft.net>, David Daney <david.daney@cavium.com>, Michael Ellerman <michael@ellerman.id.au>, Jan Glauber <jang@linux.vnet.ibm.com>, the arch/x86 maintainers <x86@kernel.org>, Xen Devel <xen-devel@lists.xensource.com>, Linux Kernel Mailing List <linux-kernel@vger.kernel.org>, Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>, peterz@infradead.org
List-Id: xen-devel@lists.xenproject.org

On 10/06/2011 12:28 PM, Steven Rostedt wrote:
>> (2) Always reserve 5 bytes of space, but if the distance is small enough
>> patch in a 2-byte jump.  That doesn't help with the icache footprint.
> I don't think this one is worth it.

I disagree.  This is what I benchmarked as having a 5% improvement.  If
squashing out the padding helps, then that's a separate optimisation.

    J