On Mon, 7 Feb 2022 11:55:18 +0100 Christophe Leroy <christophe.leroy@xxxxxxxxxx> wrote: > While building a small config with CONFIG_CC_OPTIMISE_FOR_SIZE, > I ended up with more than 50 times the following function in vmlinux: > > c00243bc <copy_overflow>: > c00243bc: 94 21 ff f0 stwu r1,-16(r1) > c00243c0: 7c 85 23 78 mr r5,r4 > c00243c4: 7c 64 1b 78 mr r4,r3 > c00243c8: 3c 60 c0 62 lis r3,-16286 > c00243cc: 7c 08 02 a6 mflr r0 > c00243d0: 38 63 5e e5 addi r3,r3,24293 > c00243d4: 90 01 00 14 stw r0,20(r1) > c00243d8: 4b ff 82 45 bl c001c61c <__warn_printk> > c00243dc: 0f e0 00 00 twui r0,0 > c00243e0: 80 01 00 14 lwz r0,20(r1) > c00243e4: 38 21 00 10 addi r1,r1,16 > c00243e8: 7c 08 03 a6 mtlr r0 > c00243ec: 4e 80 00 20 blr > > That function being a non conditional warning on an error path, > it is not worth inlining. > > Outline it. "uninline" is the conventional term for this. > This reduces the size of vmlinux by almost 4kbytes. Did you consider uninlining check_copy_size() instead?
