From: "H. Peter Anvin" Subject: Re: [RFC 0/2] __vdso_findsym Date: Sat, 14 Jun 2014 16:36:15 -0700 Message-ID: <539CDC6F.6010501@zytor.com> References: <20140614213000.GO179@brightrain.aerifal.cx> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Andy Lutomirski , Rich Felker Cc: Russ Cox , Linux API , Ian Taylor , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , X86 ML List-Id: linux-api@vger.kernel.org On 06/14/2014 03:38 PM, Andy Lutomirski wrote: > > Hmm. I hadn't thought of this as a size win, but I guess it could be > if there are static binaries around. > That pretty much *is* the win, because this is in effect treating the kernel vdso as a shared library. > This patch currently generates 488 bytes on text with my toolchain. > More than half of that is garbage needed to deal with the symbol > version tables, and I should be able to move a decent fraction of it > to vdso2c and therefore out of the kernel and vdso images. Now, if we can do this without adding another page then that becomes much more compelling IMO. I suspect we can if you are already down to 488 bytes. -hpa