First patch questions (target mailing list, target tree)

Hi, I'd like to send a patch to arch/x86/kernel/smp.c but I'm not sure about 2 details: 1) which branch of whose tree do I crate the patch against? According to MAINTAINERS: M: Thomas Gleixner <tglx@linutronix.de> M: Ingo Molnar <mingo@redhat.com> R: "H. Peter Anvin" <hpa@zytor.com> M: x86@kernel.org L: linux-kernel@vger.kernel.org T: git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86/core Is this the right branch and the correct tree? 2) how do I access archives of x86@kernel.org? Thanks!