What's _slaballoc?

[Pierre Abbat <phma@xxxxxxxxxxxxx>]

I'm profiling a program so that I can optimize it and hopefully get it to run in real time. Here's 
the profile of the program running under Linux:

Flat profile:

Each sample counts as 0.01 seconds.
  %   cumulative   self              self     total           
 time   seconds   seconds    calls   s/call   s/call  name    
 65.94      7.59     7.59   613648     0.00     0.00  tonegenerator::fwaves(int)
 11.29      8.89     1.30   613648     0.00     0.00  
__gnu_cxx::__enable_if<std::__is_scalar<float>::__value, float*>::__type std::__fill_n_a<float*, 
unsigned int, float>(float*, unsigned int, float const&)
  5.39      9.51     0.62 168385808     0.00     0.00  std::vector<float, std::allocator<float> 
>::operator[](unsigned int)
  2.78      9.83     0.32   991456     0.00     0.00  std::_Rb_tree<double, std::pair<double const, 
errec>, std::_Select1st<std::pair<double const, errec> >, std::less<double>, 
std::allocator<std::pair<double const, errec> > 
>::_M_lower_bound(std::_Rb_tree_node<std::pair<double const, errec> > const*, 
std::_Rb_tree_node<std::pair<double const, errec> > const*, double const&) const
  2.17     10.08     0.25 15606822     0.00     0.00  std::less<double>::operator()(double const&, 
double const&) const
  1.26     10.22     0.14   613648     0.00     0.00  mastertimer::skip()
  1.04     10.35     0.12 14558791     0.00     0.00  std::_Rb_tree<double, std::pair<double 
const, errec>, std::_Select1st<std::pair<double const, errec> >, std::less<double>, 
std::allocator<std::pair<double const, errec> > 
>::_S_key(std::_Rb_tree_node<std::pair<double const, errec> > const*)
  0.87     10.45     0.10                             main
  0.52     10.51     0.06   613648     0.00     0.00  tonegenerator::unfwave()
  0.48     10.56     0.06  8000250     0.00     0.00  std::_Rb_tree_iterator<std::pair<double 
const, errec> >::operator->() const
  0.43     10.61     0.05   999513     0.00     0.00  std::map<double, errec, std::less<double>, 
std::allocator<std::pair<double const, errec> > >::end()
  0.43     10.66     0.05   991456     0.00     0.00  std::_Rb_tree<double, std::pair<double const, 
errec>, std::_Select1st<std::pair<double const, errec> >, std::less<double>, 
std::allocator<std::pair<double const, errec> > >::find(double const&) const
  0.43     10.71     0.05   205449     0.00     0.00  downspike()
  0.35     10.75     0.04  1227298     0.00     0.00  std::vector<float, std::allocator<float> 
>::~vector()
  0.35     10.79     0.04   613648     0.00     0.00  std::vector<float, std::allocator<float> 
>::vector(std::vector<float, std::allocator<float> > const&)
  0.30     10.82     0.04  1840944     0.00     0.00  parity(unsigned int)
  0.26     10.86     0.03 14558791     0.00     0.00  std::_Rb_tree<double, std::pair<double 
const, errec>, std::_Select1st<std::pair<double const, errec> >, std::less<double>, 
std::allocator<std::pair<double const, errec> > 
>::_S_value(std::_Rb_tree_node<std::pair<double const, errec> > const*)
  0.26     10.88     0.03  2011200     0.00     0.00  std::_Rb_tree<double, std::pair<double const, 
errec>, std::_Select1st<std::pair<double const, errec> >, std::less<double>, 
std::allocator<std::pair<double const, errec> > >::end() const
  0.26     10.91     0.03  1970656     0.00     0.00  std::_Rb_tree_iterator<std::pair<double 
const, errec> >::operator!=(std::_Rb_tree_iterator<std::pair<double const, errec> > const&) 
const
  0.26     10.95     0.03  1524715     0.00     0.00  float* std::__copy_move<false, true, 
std::random_access_iterator_tag>::__copy_m<float>(float const*, float const*, float*)
  0.26     10.97     0.03   613648     0.00     0.00  std::vector<float, std::allocator<float> 
>::operator=(std::vector<float, std::allocator<float> > const&)
  0.26     11.01     0.03    22128     0.00     0.00  compdiv(double)
  0.22     11.03     0.03  7046596     0.00     0.00  std::_Rb_tree<double, std::pair<double const, 
errec>, std::_Select1st<std::pair<double const, errec> >, std::less<double>, 
std::allocator<std::pair<double const, errec> > >::_S_left(std::_Rb_tree_node_base const*)
  0.22     11.05     0.03  5504021     0.00     0.00  std::vector<float, std::allocator<float> 
>::size() const
  0.17     11.07     0.02  8056834     0.00     0.00  std::pair<double const, errec>* 
std::__addressof<std::pair<double const, errec> >(std::pair<double const, errec>&)
  0.17     11.10     0.02  1859754     0.00     0.00  __gnu_cxx::__normal_iterator<float const*, 
std::vector<float, std::allocator<float> > >::base() const
  0.17     11.12     0.02  1859754     0.00     0.00  
std::_Niter_base<__gnu_cxx::__normal_iterator<float const*, std::vector<float, 
std::allocator<float> > > >::iterator_type 
std::__niter_base<__gnu_cxx::__normal_iterator<float const*, std::vector<float, 
std::allocator<float> > > >(__gnu_cxx::__normal_iterator<float const*, std::vector<float, 
std::allocator<float> > >)
  0.17     11.13     0.02  1048032     0.00     0.00  std::vector<double, std::allocator<double> 
>::operator[](unsigned int)
  0.17     11.15     0.02   613648     0.00     0.00  std::_Vector_base<float, std::allocator<float> 
>::_M_get_Tp_allocator() const
  0.17     11.18     0.02        1     0.02    10.22  cscale()

Here's the profile under DragonFly:

Flat profile:

Each sample counts as 0.0078125 seconds.
  %   cumulative   self              self     total           
 time   seconds   seconds    calls   s/call   s/call  name    
 45.55    122.17   122.17  1255310     0.00     0.00  _slaballoc
 25.03    189.30    67.13   613648     0.00     0.00  tonegenerator::fwaves(int)
 22.74    250.29    60.99      415     0.15     0.15  write
  4.19    261.53    11.23                             .mcount
  1.11    264.50     2.98  2752043     0.00     0.00  memmove
  0.37    265.50     1.00   613648     0.00     0.00  
__gnu_cxx::__enable_if<std::__is_scalar<float>::__value, float*>::__type std::__fill_n_a<float*, 
unsigned int, float>(float*, unsigned int, float const&)
  0.22    266.09     0.59 168385808     0.00     0.00  std::vector<float, std::allocator<float> 
>::operator[](unsigned int)
  0.10    266.36     0.27   946349     0.00     0.00  std::_Rb_tree<double, std::pair<double const, 
errec>, std::_Select1st<std::pair<double const, errec> >, std::less<double>, 
std::allocator<std::pair<double const, errec> > 
>::_M_lower_bound(std::_Rb_tree_node<std::pair<double const, errec> > const*, 
std::_Rb_tree_node<std::pair<double const, errec> > const*, double const&) const
  0.06    266.53     0.17 14880846     0.00     0.00  std::less<double>::operator()(double 
const&, double const&) const
  0.05    266.67     0.14  1175511     0.00     0.00  exp
  0.05    266.79     0.12   613648     0.00     0.00  mastertimer::skip()
  0.04    266.89     0.10        1     0.10   256.25  main
  0.03    266.99     0.09  1227296     0.00     0.00  hypot
  0.02    267.05     0.06  1840944     0.00     0.00  parity(unsigned int)
  0.02    267.11     0.06   613648     0.00     0.00  tonegenerator::unfwave()
  0.02    267.17     0.06   277009     0.00     0.00  
__gnu_cxx::__enable_if<std::__is_integer<int>::__value, double>::__type std::log<int>(int)
  0.02    267.23     0.05  1524715     0.00     0.00  float* std::__copy_move<false, true, 
std::random_access_iterator_tag>::__copy_m<float>(float const*, float const*, float*)
  0.02    267.28     0.05 13879461     0.00     0.00  std::_Rb_tree<double, std::pair<double 
const, errec>, std::_Select1st<std::pair<double const, errec> >, std::less<double>, 
std::allocator<std::pair<double const, errec> > 
>::_S_key(std::_Rb_tree_node<std::pair<double const, errec> > const*)
  0.02    267.32     0.05   554079     0.00     0.00  log
  0.02    267.37     0.05   205449     0.00     0.00  downspike()
  0.02    267.42     0.05        1     0.05   241.22  cscale()

I replaced downhann(), which was taking even more time than fwaves(int), with downspike(), 
thus making the program much faster. The next function to optimize is fwaves(int), which I'm 
working on. But in DFly, _slaballoc takes more time than fwaves(int). What is it, and how can I 
optimize it?

Pierre
-- 
Jews use a lunisolar calendar; Muslims use a solely lunar calendar.