mirror of https://github.com/torvalds/linux.git
0dafe9968a
Use asm_inline for all inline assemblies which make use of the EX_TABLE or ALTERNATIVE macros. These macros expand to many lines and the compiler assumes the number of lines within an inline assembly is the same as the number of instructions within an inline assembly. This has an effect on inlining and loop unrolling decisions. In order to avoid incorrect assumptions use asm_inline, which tells the compiler that an inline assembly has the smallest possible size. In order to avoid confusion when asm_inline should be used or not, since a couple of inline assemblies are quite large: the rule is to always use asm_inline whenever the EX_TABLE or ALTERNATIVE macro is used. In specific cases there may be reasons to not follow this guideline, but that should be documented with the corresponding code. Using the inline qualifier everywhere has only a small effect on the kernel image size: add/remove: 0/10 grow/shrink: 19/8 up/down: 1492/-1858 (-366) The only location where this seems to matter is load_unaligned_zeropad() from word-at-a-time.h where the compiler inlines more functions within the dcache code, which is indeed code where performance matters. Suggested-by: Juergen Christ <jchrist@linux.ibm.com> Reviewed-by: Juergen Christ <jchrist@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> |
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| .. | ||
| .gitignore | ||
| Makefile | ||
| als.c | ||
| alternative.c | ||
| boot.h | ||
| clz_ctz.c | ||
| cmdline.c | ||
| ctype.c | ||
| decompressor.c | ||
| decompressor.h | ||
| ebcdic.c | ||
| head.S | ||
| head_kdump.S | ||
| install.sh | ||
| ipl_data.c | ||
| ipl_parm.c | ||
| ipl_report.c | ||
| ipl_vmparm.c | ||
| kaslr.c | ||
| kmsan.c | ||
| machine_kexec_reloc.c | ||
| mem.S | ||
| pgm_check.c | ||
| physmem_info.c | ||
| printk.c | ||
| sclp_early_core.c | ||
| startup.c | ||
| string.c | ||
| uv.c | ||
| uv.h | ||
| version.c | ||
| vmem.c | ||
| vmlinux.lds.S | ||