rt0
Languages and libraries
c runtime
SHOW HN2015
49points
10comments
#574of 2,565 in 2015
Top 23%of 2015 by points
How HN took it
QuietFewer than 5 comments about the project
0 positive, 0 neutral or asking, 0 mixed, 1 critical, out of 1 comments about the project.
Idea: 0 for, 1 against
The thread, comment by comment
Each row is a top-level comment and its replies, in HN's order. Select a cell to open that comment on HN.
positive neutral or mixed critical about another commenter or something else the maker
What HN said
Objections
sbrk is nearly deprecated; mmap or mprotect preferred by modern allocators
From 2 comments
What is sbrk even used for anymore? Surely most heap allocators use mmap/mprotect directly these days. There's no downside. EDIT: Not trying to rain on anyone's parade, I think…
duaneb on HNsbrk competes with mmap, not mprotect. And yes, I would expect mmap to be used in most modern systems. OS X, for instance, just emulates sbrk with a large static buffer, and it…
koenigdavidmj on HN
sbrk makes less sense with virtual memory
From 1 comment
Yea, sbrk makes sense in a flat address space. I don't think it makes as much sense with virtual memory.
duaneb on HN
Questions
What is sbrk used for anymore?
From 1 comment
What is sbrk even used for anymore? Surely most heap allocators use mmap/mprotect directly these days. There's no downside. EDIT: Not trying to rain on anyone's parade, I think…
duaneb on HN
How does virtual memory improve security?
From 1 comment
Could you explain how virtual memory makes a process more secure? My intuition is that it would be another source of contention to manage (like CPU, RAM, IO, etc). Maybe you're…
oso2k on HN
Alternatives named
mmap
From 2 comments
What is sbrk even used for anymore? Surely most heap allocators use mmap/mprotect directly these days. There's no downside. EDIT: Not trying to rain on anyone's parade, I think…
duaneb on HNsbrk competes with mmap, not mprotect. And yes, I would expect mmap to be used in most modern systems. OS X, for instance, just emulates sbrk with a large static buffer, and it…
koenigdavidmj on HN