Please help me test this glibc patch

[Justus Winter]

Hello,

please help me test this glibc patch.  It could bring a significant
speedup to certain workloads, namely those that copy lots of memory in
chunks.

I wrote a micro-benchmark for this:

teythoon@darnassus:~/build/time-memcpy$ bash driver.bash
   size iterations      gcc_memcpy      memcpy          vm_copy
   4096   16777216      6.09            6.07            15.67
   8192    8388608      7.02            6.29            7.87
  12288    5592405      5.19            5.29            5.22
  16384    4194304      6.36            5.71            3.56
  32768    2097152      7.03            7.03            2.03
  65536    1048576      7.29            7.33            0.87

The results are more consistent (but similar) on a quieter system.

This is copying a buffer of SIZE, ITERATIONS times, a total of 2^36
bytes.  gcc_memcpy is a self-written memcpy compiled with -O3 and
-fno-builtin-memcpy, memcpy is from glibc, vm_copy is using vm_copy.

You can find it here
http://darnassus.sceen.net/gitweb/teythoon/time-memcpy.git/

Thanks,
Justus