Hands-On System Programming with Linux

Scenario 3 – large allocations option

This time, we pass the 2 parameter, asking the program to perform larger allocations (greater than MMAP_THRESHOLD):

$ ./malloc_brk_test 2                              init_brk =        0x2209000 #: malloc(       n) =        heap_ptr           cur_brk   delta                                                       [cur_brk-init_brk][...] 3: malloc(  136168) =   0x7f57288cd010         0x222a000 [135168]Arena 0:system bytes     =     135168in use bytes     =       5792Total (incl. mmap):system bytes     =     274432in use bytes     =     145056max mmap regions =          1max mmap bytes   =     139264 4: malloc( 1048576) =   0x7f57287c7010         0x222a000 [135168]Arena 0:system bytes     =     135168in use bytes     =       5792Total (incl. mmap):system bytes     =    1327104in use bytes     =    1197728max mmap regions =          2max mmap bytes   =    1191936$                     

(Note that the preceding code we have clipped the output of the first ...