Re: GNU make 3.99.92 release candidate is available

[Boris Kolpackov]

Hi,

I just got a new box setup for development and was shocked to find
out that make 3.99.XX is about 50% slower than on my old box.

The test I run is an up-to-date check on a fairly large non-recursive
build system. The hardware is as follows:

Old: Xeon E5520 2.3GHz, 24G RAM, SAS2 spinning disks
New: Xeon E5-2630 2.3GHz, 64G RAM, SSD disks

I don't believe disk performance is an issue here since everything has
been cached into memory (the test is run multiple times).

The same up-to-date check takes 0.5s on my old box and 0.73s on the
new one. In fact, the performance improvement I observed compared
to 3.82 is completely wiped out on the new box; both versions take
about the same time.

I tried to build make with various C compilers (GCC 4.7, 4.8, Clang
3.3) and with various optimization options (-O3, -march=native) as
well as run the same binary on both machines, all without any
difference.

Also this is not a general problem with the new box. It is faster
than the old. For example, C compilation is about 30% faster.

Needless to say, this is bad news for me since now I have to wait
longer for make to even start the compilation. So any ideas here
are welcome.

Boris

-- 
Boris Kolpackov, Code Synthesis        http://codesynthesis.com/~boris/blog
Compiler-based ORM system for C++      http://codesynthesis.com/products/odb