This avoids some problems with gcc 4.x and earlier generating
invalid unwind information. In 4.1 the option is default
when unwind information is enabled.
And it seems to generate smaller code too, so it's probably
a good thing on its own. With gcc 4.0:
i386:
4683198 902112 480868 6066178 5c9002 vmlinux (before)
4449895 902112 480868 5832875 5900ab vmlinux (after)
x86-64:
4939761 1449584 648216 7037561 6b6279 vmlinux (before)
4854193 1449584 648216 6951993 6a1439 vmlinux (after)
On 4.1 it shouldn't make much difference because it is
default when unwind is enabled anyways.
Suggested by Michael Matz and Jan Beulich
Cc: jbeulich@novell.com
Signed-off-by: Andi Kleen <ak@suse.de>
cdfce1f571