From mboxrd@z Thu Jan 1 00:00:00 1970 From: mark.rutland@arm.com (Mark Rutland) Date: Fri, 22 Jan 2016 15:02:56 +0000 Subject: [PATCH] Eliminate the .eh_frame sections from the aarch64 vmlinux and kernel modules In-Reply-To: <56A2400D.5080707@redhat.com> References: <1453434986-19307-1-git-send-email-wcohen@redhat.com> <56A2400D.5080707@redhat.com> Message-ID: <20160122150256.GC11645@leverpostej> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, Jan 22, 2016 at 09:43:25AM -0500, William Cohen wrote: > On 01/22/2016 02:41 AM, Ard Biesheuvel wrote: > > On 22 January 2016 at 04:56, William Cohen wrote: > >> By default the aarch64 gcc generates .eh_frame sections. Unlike > >> .debug_frame sections, the .eh_frame sections are loaded into memory > >> when the associated code is loaded. On an example kernel being built > >> with this default the .eh_frame section in vmlinux used an extra 1.7MB > >> of memory. The x86 disables the creation of the .eh_frame section. > >> The aarch64 should probably do the same to save some memory. > >> > > > > With my GCC-4.9.3 Linaro toolchain, I am not getting .eh_frame > > sections only .debug_frame sections. The patch still makes sense imo, > > but it appears to be redundant in some cases, and it would be useful > > to figure out why. Which toolchain have you tested this with? > > Hi, > > I have observed the .eh_frame being generated with gcc-5.3.1 that is in Fedora 23. FWIW, I do not see this with the Linaro 15.08 GCC 5.1.1. It would be interesting to know if that's something that changed upstream between 5.1.x and 5.3.x or if that's a Fedora-specific configuration option, but either way the patch seems reasonable. Thanks, Mark.