Re: musl for ARM

[Szabolcs Nagy <nsz@port70.net>]

* Rich Felker <dalias@aerifal.cx> [2012-10-02 09:48:43 -0400]:
> One area you can get vastly better performance with musl is
> application startup overhead. Especially with static linking, but even
> with dynamic linking if your only .so is libc, the startup time is
> 2-5x faster than glibc, which really makes a difference to the runtime
> of shell scripts (like configure) that invoke tons of external
> programs.
> 

i don't see this mentioned on the libc comparision table

is this the self-exec benchmark?

> > However, when building busybox, there are some header files clashes,
> > resulting in conflicting types.
> > An example of it:
> > ---------------------
> > In file included from
> > /opt/cross/arm-linux-musleabi/lib/gcc/arm-linux-musleabi/4.7.1/../../../../arm-linux-musleabi/include/linux/kd.h:3:0,
> >                  from console-tools/kbd_mode.c:23:
> > /opt/cross/arm-linux-musleabi/lib/gcc/arm-linux-musleabi/4.7.1/../../../../arm-linux-musleabi/include/linux/types.h:12:26:
> > error: conflicting types for ???fd_set???
> > In file included from
> > /opt/cross/arm-linux-musleabi/lib/gcc/arm-linux-musleabi/4.7.1/../../../../arm-linux-musleabi/include/sys/time.h:9:0,
> >                  from include/libbb.h:45,
> >                  from console-tools/kbd_mode.c:22:
> > /opt/cross/arm-linux-musleabi/lib/gcc/arm-linux-musleabi/4.7.1/../../../../arm-linux-musleabi/include/sys/select.h:25:3:
> > note: previous declaration of ???fd_set??? was here
> > ---------------------
> 
> It looks like these kernel headers are not sanitized for compatibility
> with userspace..?
> 


linux/types.h only typedefs fd_set ifdef __KERNEL__
so userspace code shouldnt see fd_set at all,
only __kernel_fd_set

i think busybox is doing something wrong there