Re: incorrect malloc_stats output

[wmglo]

Hi again,

> However, the above is independent of the bug. malloc_stats actually ends
> up  going to 4.5GB or so on my 4GB box. The Total below of 3.67Gb is 
> ridiculous as user space ends at 3GB. 
> 
> Arena 0:
> system bytes     = 2995479196
> in use bytes     = 2994988452
> Arena 1:
> system bytes     =   50745344
> in use bytes     =   50739752
> Arena 2:
> system bytes     =  208867328
> in use bytes     =  208865872
> Arena 3:
> system bytes     =  171769856
> in use bytes     =  171767664
> Total (incl. mmap):
> system bytes     = 3670499996
> in use bytes     = 3670000012
> max mmap regions =         29
> max mmap bytes   =  243638272

Please note also that the "Total" including mmap is unreliable when
multiple threads are used.  The counting of the size of mmapped
regions as in

    mp_.mmapped_mem += size;

is done outside a mutex lock for performance, and may not be atomic.

However, even your total without mmap (sum of system bytes for Arena
0-3) exceeds 3GB, which seems bogus unless you have a kernel where the
top of stack would be at 0xD0000000.

Regards,
Wolfram.