On 10/12/23 13:59, Uros Bizjak wrote:
On Thu, Oct 12, 2023 at 10:53 PM Dave Hansen <[email protected]> wrote:
On 10/12/23 13:12, Uros Bizjak wrote:
The last patch introduces (%rip) suffix and uses it for x86_64 target,
resulting in a small code size decrease: text data bss dec hex filename
25510677 4386685 808388 30705750 1d48856 vmlinux-new.o 25510629 4386685
808388 30705702 1d48826 vmlinux-old.o
I feel like I'm missing some of the motivation here.
50 bytes is great and all, but it isn't without the cost of changing
some rules and introducing potential PER_CPU_ARG() vs. PER_CPU_VAR()
confusion.
Are there some other side benefits? What else does this enable?
These changes are necessary to build the kernel as Position
Independent Executable (PIE) on x86_64 [1]. And since I was working in
percpu area I thought that it was worth implementing them.
[1]
https://lore.kernel.org/lkml/[email protected]/
Are you PIC-adjusting the percpu variables as well?
-hpa
