Re: [Qemu-devel] [PATCH 1.3] build: compile translate.o at -O1 optimization

[Paolo Bonzini <pbonzini@redhat.com>]

Il 27/11/2012 10:27, Wenchao Xia ha scritto:
>   In tcg case I think translate.o will influent performance obviously,
> how about adding an option "fast-build" to use -O1 for it by default.
> If you agree I will adding that after this patch upstream which fix
> build bot failure quickly.

This is not about having a fast or slow build, it's about not requiring
a ludicrous amount of memory...  Besides, translate.c is usually not too
high in the profiles.  Most of the time is spent _executing_
JIT-translated code, not translating it.

Note that there is probably one or two GCC options that can be
fine-tuned to avoid the explosion instead of just -O1 vs. -O2.  If you
have an affected machine (F18) you can help by compiling translate.c
with -O2 -ftime-report.  I planned to do this today, but I first need to
install a F18 virtual machine.

Paolo