Hello everyone,
AFAIU, functions only used at system init are tagged __init to have
the linker store them in a separate .init.text section, so memory can
be reclaimed once initialization is complete. Is that correct?
The corresponding tag for data is __initdata (section .init.data)
I started wondering if the string literals used in an __init functions
were automatically marked __initdata.
Looking at the objdump output, I see that the string literals are,
in fact, stored in the .rodata section. I suppose that .rodata is NOT
reclaimed after init?
This way seems to work:
static char XyZa[] __initdata = KERN_ALERT "foo";
static const char XyZb[] __initconst = KERN_ALERT "bar";
void __init XyZc(void) { printk(XyZa); printk(XyZb); }
$ arm-linux-gnueabihf-objdump -xd arch/arm/mach-tangox/time.o | grep XyZ
00000000 l O .init.data 00000006 XyZa
00000000 l O .init.rodata 00000006 XyZb
00000000 g F .init.text 00000028 XyZc
00000000 <XyZc>:
$ arm-linux-gnueabihf-objdump -xd vmlinux | grep XyZ
c021e360 l O .init.data 00000006 XyZa
c0220090 l O .init.data 00000006 XyZb
c020d928 g F .init.text 00000028 XyZc
c020d928 <XyZc>:
c020d928 <XyZc>:
c020d928: e1a0c00d mov ip, sp
c020d92c: e92dd800 push {fp, ip, lr, pc}
c020d930: e24cb004 sub fp, ip, #4
c020d934: e30e0360 movw r0, #58208 ; 0xe360
c020d938: e34c0021 movt r0, #49185 ; 0xc021
c020d93c: ebfe00c9 bl c018dc68 <printk>
c020d940: e3000090 movw r0, #144 ; 0x90
c020d944: e34c0022 movt r0, #49186 ; 0xc022
c020d948: ebfe00c6 bl c018dc68 <printk>
c020d94c: e89da800 ldm sp, {fp, sp, pc}
Did I miss something in init.h?
Or should it be done like above to reclaim string literals?
Regards.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
