ubuntu - Who zeroes pages while calling calloc() in Linux? -


i aware implementer has choice of whether wants 0 malloc page or let os give him zeroed page (for more optimization purposes).

my question simple - in ubuntu 14.04 lts comes linux kernel 3.16 , gcc 4.8.4, 0 pages? in user land or kernel land?

it can depend on memory came from. calloc code userland, , 0 memory page gets re-used process. happens when memory used , freed, not returned os. however, if page newly allocated process, come cleared 0 os (for security purposes), , not need cleared calloc. means calloc can potentially faster calling malloc followed memset, since can skip memset if knows zeroed.


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