From: wcohen@redhat.com (William Cohen)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] Eliminate the .eh_frame sections from the aarch64 vmlinux and kernel modules
Date: Fri, 22 Jan 2016 09:43:25 -0500 [thread overview]
Message-ID: <56A2400D.5080707@redhat.com> (raw)
In-Reply-To: <CAKv+Gu9j7VGqoOWOZ1T1CVQZfSy9HL9wzvAX83bRiks=6b3dzw@mail.gmail.com>
On 01/22/2016 02:41 AM, Ard Biesheuvel wrote:
> On 22 January 2016 at 04:56, William Cohen <wcohen@redhat.com> 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.
-Will
>
>
>> Signed-off-by: William Cohen <wcohen@redhat.com>
>> ---
>> arch/arm64/Makefile | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
>> index cd822d8..094a137 100644
>> --- a/arch/arm64/Makefile
>> +++ b/arch/arm64/Makefile
>> @@ -27,6 +27,7 @@ $(warning LSE atomics not supported by binutils)
>> endif
>>
>> KBUILD_CFLAGS += -mgeneral-regs-only $(lseinstr)
>> +KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
>> KBUILD_AFLAGS += $(lseinstr)
>>
>> ifeq ($(CONFIG_CPU_BIG_ENDIAN), y)
>> --
>> 2.5.0
>>
>>
>> _______________________________________________
>> linux-arm-kernel mailing list
>> linux-arm-kernel at lists.infradead.org
>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2016-01-22 14:43 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-22 3:56 [PATCH] Eliminate the .eh_frame sections from the aarch64 vmlinux and kernel modules William Cohen
2016-01-22 7:41 ` Ard Biesheuvel
2016-01-22 14:43 ` William Cohen [this message]
2016-01-22 15:02 ` Mark Rutland
2016-01-22 15:36 ` William Cohen
2016-01-22 17:02 ` Mark Rutland
2016-01-22 19:03 ` William Cohen
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