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Merge branch 'vm/lazy-loading' into vm/page-swap-synch

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This commit is contained in:
Themis Demetriades
2024-12-04 19:11:37 +00:00
parent 4bf6914cfa
commit 1e236a5c47
7 changed files with 59 additions and 43 deletions
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47
src/userprog/process.c
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@@ -24,6 +24,7 @@
#include "threads/vaddr.h"
#include "threads/synch.h"
#include "devices/timer.h"
#include "vm/page.h"
#ifdef VM
#include "vm/frame.h"
#endif
@@ -118,6 +119,7 @@ process_execute (const char *cmd)
static void *get_usr_kpage (enum palloc_flags flags, void *upage);
static void free_usr_kpage (void *kpage);
bool install_page (void *upage, void *kpage, bool writable);
static bool process_init_stack (char *cmd_saveptr, void **esp, char *file_name);
static void *push_to_stack (void **esp, void *data, size_t data_size);
@@ -363,6 +365,7 @@ process_exit (void)
/* Clean up all open files */
hash_destroy (&cur->open_files, fd_cleanup);
hash_destroy (&cur->pages, page_cleanup);
/* Close the executable file, implicitly allowing it to be written to. */
if (cur->exec_file != NULL)
@@ -620,7 +623,6 @@ load (const char *file_name, void (**eip) (void), void **esp)
done:
/* We arrive here whether the load is successful or not. */
file_close (file);
lock_release (&filesys_lock);
return success;
}
@@ -688,58 +690,29 @@ validate_segment (const struct Elf32_Phdr *phdr, struct file *file)
or disk read error occurs. */
static bool
load_segment (struct file *file, off_t ofs, uint8_t *upage,
uint32_t read_bytes, uint32_t zero_bytes, bool writable)
uint32_t read_bytes, uint32_t zero_bytes, bool writable)
{
ASSERT ((read_bytes + zero_bytes) % PGSIZE == 0);
ASSERT (pg_ofs (upage) == 0);
ASSERT (ofs % PGSIZE == 0);
file_seek (file, ofs);
while (read_bytes > 0 || zero_bytes > 0)
while (read_bytes > 0 || zero_bytes > 0)
{
/* Calculate how to fill this page.
We will read PAGE_READ_BYTES bytes from FILE
and zero the final PAGE_ZERO_BYTES bytes. */
size_t page_read_bytes = read_bytes < PGSIZE ? read_bytes : PGSIZE;
size_t page_zero_bytes = PGSIZE - page_read_bytes;
/* Check if virtual page already allocated */
struct thread *t = thread_current ();
uint8_t *kpage = pagedir_get_page (t->pagedir, upage);
if (kpage == NULL){
/* Get a new page of memory. */
kpage = get_usr_kpage (0, upage);
if (kpage == NULL){
return false;
}
/* Add the page to the process's address space. */
if (!install_page (upage, kpage, writable))
{
free_usr_kpage (kpage);
return false;
}
} else {
/* Check if writable flag for the page should be updated */
if(writable && !pagedir_is_writable(t->pagedir, upage)){
pagedir_set_writable(t->pagedir, upage, writable);
}
}
/* Load data into the page. */
if (file_read (file, kpage, page_read_bytes) != (int) page_read_bytes){
return false;
}
memset (kpage + page_read_bytes, 0, page_zero_bytes);
/* Add the page metadata to the SPT to be lazy loaded later on */
if (page_insert (file, ofs, upage, page_read_bytes, page_zero_bytes,
writable, PAGE_EXECUTABLE) == NULL)
return false;
/* Advance. */
read_bytes -= page_read_bytes;
zero_bytes -= page_zero_bytes;
ofs += PGSIZE;
upage += PGSIZE;
}
return true;