Imbus/xv6-riscv-kernel
1
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

no /* */ comments

Browse source
This commit is contained in:
rsc 2006-09-06 17:50:20 +00:00
parent 9e9bcaf143
commit f552738889
22 changed files with 347 additions and 371 deletions
Download patch file Download diff file Expand all files Collapse all files

31
kalloc.c
View file

@ -1,11 +1,9 @@
/*
* physical memory allocator, intended to be used to allocate
* memory for user processes. allocates in 4096-byte "pages".
* free list is sorted and combines adjacent pages into
* long runs, to make it easier to allocate big segments.
* one reason the page size is 4k is that the x86 segment size
* granularity is 4k.
*/
// Physical memory allocator, intended to allocate
// memory for user processes. Allocates in 4096-byte "pages".
// Free list is kept sorted and combines adjacent pages into
// long runs, to make it easier to allocate big segments.
// One reason the page size is 4k is that the x86 segment size
// granularity is 4k.
#include "param.h"
#include "types.h"
@ -23,11 +21,10 @@ struct run {
};
struct run *freelist;
/*
* initialize free list of physical pages. this code
* cheats by just considering the one megabyte of pages
* after _end.
*/
// Initialize free list of physical pages.
// This code cheats by just considering one megabyte of
// pages after _end. Real systems would determine the
// amount of memory available in the system and use it all.
void
kinit(void)
{
@ -95,11 +92,9 @@ kfree(char *cp, int len)
release(&kalloc_lock);
}
/*
* allocate n bytes of physical memory.
* returns a kernel-segment pointer.
* returns 0 if there's no run that's big enough.
*/
// Allocate n bytes of physical memory.
// Returns a kernel-segment pointer.
// Returns 0 if the memory cannot be allocated.
char*
kalloc(int n)
{