Re: Memory overcommitting (was Re: http://www.redhat.com/redhat/)

Andrew E. Mileski (aem@netcom.ca)
Wed, 19 Feb 1997 23:40:38 -0500 (EST)

> SUICIDE! No wonder Linux gets such a rap for being unreliable. (If this is
> truely how things work. Someone please tell me this isn't so.)
> As a programmer I expect that when I have sucessfully requested memory to
> be allocated, that it really has happened. It now appears that on top of
> everything else that writing to memory at the wrong time, I could run of
> virtual memory.

Well, have you ever written a heap manager before? You allocate more
memory from the system than you need, then break it up into smaller
chunks to be allocated on demand. The system (kernel) only sees the
heap manager's allocations (big and few) not the program's allocations
(smaller and many more). Instead of lots of system calls, there are
only a couple (faster). Not to mention that the memory would be sitting
around doing nothing until some process touches it....what a waste.

--
Andrew E. Mileski   mailto:aem@netcom.ca
Linux Plug-and-Play Kernel Project http://www.redhat.com/linux-info/pnp/
XFree86 Matrox Team http://www.bf.rmit.edu.au/~ajv/xf86-matrox.html