5 ms·

It's actually not a bad suggestion #define BUF_INITIAL 1024 char buf[BUF_INITIAL]; int main(int argc, char** argv) { char* p;

It's actually not a bad suggestion #define BUF_INITIAL 1024 char buf[BUF_INITIAL]; int main(int argc, char** argv) { char* p; ... p = len > BUF_INITIAL ? malloc(len) : buf; ... write(1, p, len); ... }

cpeterso 15y ago
djb's allocator alloc() does this. He preallocates a 4 KB static buffer before hitting system malloc(). Avoiding the overhead of malloc() is pretty important for the performance of systems like qmail that fork many small processes.
- sliverstorm 15y ago
  Many small processes? How many? 4 KB * (many) could be frightening.
  - jff 15y ago
    If your system has 32,000 processes and you allocate 4 KB to each of them... that's 128 MB. I'm not crapping my pants at that figure because even the oldest machine in my office, an old Thinkpad, has 2 GB of RAM.
- tedunangst 15y ago
  That's ridiculous. The overhead of fork is about a bajillion times higher than malloc.
  - aidenn0 15y ago
    Are you sure? I'd bet it's greater, I'd not bet that it's an order of magnitude better, fork() has been optimized a lot more than brk().
  - adestefan 15y ago
    With a COW fork() I bet it's smaller. I smell a test coming on, but alas it's late here and I'm going to bed. I'm also guessing that 4k was chosen because a malloc() of 1 page is faster than a malloc() of >1 page. Of course that's with the assumption that the systems use a 4k page size.