For now, vmlinux relocation functions for relocatable kernel are
implemented as an array of handlers of a particular type.
Convert that array into a single switch-case function to:
- remove unused arguments;
- change the return type of simple handlers to void;
- remove the array and don't use any data at all;
- avoid using indirect calls;
- allow the compiler to inline and greatly optimize
the relocation function[s];
and also mark do_relocations() and show_kernel_relocation() static
as they aren't used anywhere else.
The result on MIPS32 R2 with GCC 10.2 -O2 is:
scripts/bloat-o-meter -c arch/mips/kernel/__relocate.o arch/mips/kernel/relocate.o
add/remove: 0/6 grow/shrink: 1/0 up/down: 356/-640 (-284)
Function old new delta
relocate_kernel 852 1208 +356
apply_r_mips_32_rel 20 - -20
apply_r_mips_hi16_rel 40 - -40
apply_r_mips_64_rel 44 - -44
apply_r_mips_26_rel 144 - -144
show_kernel_relocation 164 - -164
do_relocations 228 - -228
Total: Before=1780, After=1496, chg -15.96%
add/remove: 0/1 grow/shrink: 0/0 up/down: 0/-76 (-76)
Data old new delta
reloc_handlers_rel 76 - -76
Total: Before=92, After=16, chg -82.61%
add/remove: 0/0 grow/shrink: 0/0 up/down: 0/0 (0)
RO Data old new delta
Total: Before=0, After=0, chg +0.00%
All functions were collapsed into the main one, relocate_kernel().
Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
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