hybrid allocator tuning

Set various pragmas and defines to tune the hybrid allocator.

Performance test was the time takes to allocate or deallocate as
appropriate 1,000,000 times from a set of 100,000 pointers, selected at
random, with sizes generated randomly with min 2, max 5960, avg 46.
The function was exp(8 - log(2 + rand(0..1023))) * rand(1 or 4).

The following parameters were chosen:
   * pragma arm, for ~1.2%
   * pragma Otime, for ~3%
   * pragma O2, already the compiler default, just to be sure
   * all possible slab sizes enabled, for ~1%

NB Disabling BTrace would also gain ~1.5%, but that seems like a bad
thing to do. Not done.

Task-number: QT-3967
Reviewed-by: Shane Kearns

0 files changed, 0 insertions, 0 deletions