X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?p=pintos-anon;a=blobdiff_plain;f=src%2Fthreads%2Fpalloc.c;h=4fc8394c8f078a20c5a48722c36e3e022658620e;hp=eab41e4811b15d074acf74ab27592d9eb56bb678;hb=a03618133f7df0954802a470a4bee7674f7aed45;hpb=f415a37905c57f61b444806bf84f5405184452aa

diff --git a/src/threads/palloc.c b/src/threads/palloc.c
index eab41e4..4fc8394 100644
--- a/src/threads/palloc.c
+++ b/src/threads/palloc.c
@@ -7,7 +7,6 @@
 #include <stdint.h>
 #include <stdio.h>
 #include <string.h>
-#include "threads/init.h"
 #include "threads/loader.h"
 #include "threads/synch.h"
 #include "threads/vaddr.h"
@@ -35,26 +34,20 @@ struct pool
   };
 
 /* Two pools: one for kernel data, one for user pages. */
-struct pool kernel_pool, user_pool;
-
-/* Maximum number of pages to put in user pool. */
-size_t user_page_limit = SIZE_MAX;
+static struct pool kernel_pool, user_pool;
 
 static void init_pool (struct pool *, void *base, size_t page_cnt,
                        const char *name);
 static bool page_from_pool (const struct pool *, void *page);
 
-/* Initializes the page allocator. */
+/* Initializes the page allocator.  At most USER_PAGE_LIMIT
+   pages are put into the user pool. */
 void
-palloc_init (void) 
+palloc_init (size_t user_page_limit)
 {
-  /* End of the kernel as recorded by the linker.
-     See kernel.lds.S. */
-  extern char _end;
-
-  /* Free memory. */
-  uint8_t *free_start = pg_round_up (&_end);
-  uint8_t *free_end = ptov (ram_pages * PGSIZE);
+  /* Free memory starts at 1 MB and runs to the end of RAM. */
+  uint8_t *free_start = ptov (1024 * 1024);
+  uint8_t *free_end = ptov (init_ram_pages * PGSIZE);
   size_t free_pages = (free_end - free_start) / PGSIZE;
   size_t user_pages = free_pages / 2;
   size_t kernel_pages;