diff options
Diffstat (limited to 'share/doc/papers/malloc/kernel.ms')
| -rw-r--r-- | share/doc/papers/malloc/kernel.ms | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/share/doc/papers/malloc/kernel.ms b/share/doc/papers/malloc/kernel.ms index 220e502..787a581 100644 --- a/share/doc/papers/malloc/kernel.ms +++ b/share/doc/papers/malloc/kernel.ms @@ -6,7 +6,7 @@ .\" this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp .\" ---------------------------------------------------------------------------- .\" -.\" $Id: kernel.ms,v 1.2 1996/10/05 18:37:06 wosch Exp $ +.\" $Id: kernel.ms,v 1.3 1996/11/14 08:10:31 phk Exp $ .\" .ds RH The kernel and memory .NH @@ -30,7 +30,7 @@ for the data and bss section combined and one for the stack. On some systems the text shared a segment with the data and bss, and was consequently just as writable as them. .PP -In this setup all the brk(2) system call have to do is to find the +In this setup all the brk(2) system call has to do is to find the right amount of free storage, possibly moving things around in physical memory, maybe even swapping out a segment or two to make space, and change the upper limit on the data segment according to the address given. @@ -38,17 +38,17 @@ and change the upper limit on the data segment according to the address given. In a more modern page based virtual memory implementation this is still pretty much the situation, except that the granularity is now pages: The kernel finds the right number of free pages, possibly paging some -pages out to free them up, and then plug them into the page-table of +pages out to free them up, and then plugs them into the page-table of the process. .PP As such the difference is very small, the real difference is that in the old world of swapping, either the entire process was in primary -storage (or it wouldn't be selected to be run) in a modern VM kernel, +storage or it wouldn't be selected to be run. In a modern VM kernel, a process might only have a subset of its pages in primary memory, the rest will be paged in, if and when the process tries to access them. .PP -Only very few programs deal with the brk(2) interface directly, the -few that does usually have their own memory management facilities. +Only very few programs deal with the brk(2) interface directly. +The few that do usually have their own memory management facilities. LISP or FORTH interpreters are good examples. Most other programs use the .B malloc(3) |
