[RFC] Un-staticise the toolchain

Erik Cederstrand erik at cederstrand.dk
Thu May 3 09:18:16 UTC 2012

Den 02/05/2012 kl. 13.56 skrev John Baldwin:
>> Static version:
>> * 0.09 ms spent execve'ing /usr/bin/make
>> * The rest is mostly sysctl calls
>> Dynamic version:
>> * 0.09 ms spent execve'ing ./dynamicmake and /libexec/ld-elf.so.1
>> * 0.18 ms spent loading libc.so.7 (incl. reading /etc/libmap.conf and /var/run/ld-elf.so.hints)
>> * 0.11 ms spent calling sysarch(0x81,0x7fffffffXXXX) (static version also does this but only uses 0.01 ms. No idea why)
>> * The rest is mostly sysctl and sigprocmask calls
> Keep in mind that the first time each system call is invoked, the runtime
> linker has to resolve the symbol.  You can force the linker to do all
> that when the object is loaded instead by setting LD_BIND_NOW=yes in the
> environment of dynamicmake.  If that makes the sysarch() call take 0.01
> ms, then you know that the extra 0.10 ms is because of rtld doing the
> lookup of sysarch() on the first sysarch() call.

Thanks for the suggestion. There is only a single sysarch() call in each version so I'm not sure that would help. Anyway, setting LD_BIND_NOW in the dynamic case just made the sysarch() call 0.20 ms slower without speeding up anything else.

Kind regards,

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