Add -Wl,--emit-relocs or -Wl,-q Leading to performance degradation

[zpget]

gcc8.2 add -Wl,--emit-relocs or -Wl,-q Leading 10% cpu degradation

[yota9]

How did you measured it? The -q option just adds a few information non-allocatable sections, it must not influence on the performance. You can strip you binary and it should be the same, as without -q linker option.

[zpget]

How did you measured it? The -q option just adds a few information non-allocatable sections, it must not influence on the performance. You can strip you binary and it should be the same, as without -q linker option.

• TEST 1 AB diff

1. same code build A with no -q VS B with -q
2. same qps press on A and B
3. static container cpu usage test more than 5 times B > A 10%+

• TEST 2 AA diff

1. same code build A with no -q
2. same qps press on A and A
3. static container cpu usage test more than 5 times CPU cost same

Is there anything influence the -q link?

[aaupov]

To reiterate what @yota9 said: -q/--emit-relocs option instructs linker to preserve relocation sections, but these sections are not loaded into memory during the execution (they are non-allocatable). So the B side will only take more space on disk, but not in the memory during the execution. The option doesn't affect code generation. Text section contents should be identical between A side and B side - you can check that using objdump -dj.text.

Binutils reference: https://sourceware.org/binutils/docs/ld/Options.html