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Merge remote-tracking branch 'origin/vm/page-swap-synch' into vm/virtual-memory/saleh

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# Conflicts:
#	.gitlab-ci.yml
#	src/Makefile.build
#	src/threads/thread.c
#	src/userprog/exception.c
#	src/userprog/process.c
#	src/vm/frame.c
#	src/vm/page.c
#	src/vm/page.h
#	src/vm/stackgrowth.c
#	src/vm/stackgrowth.h
This commit is contained in:
sBubshait
2024-12-05 02:21:53 +00:00
parent 1a8eb1bbe5 ac31fb1e1e
commit f13fd435cd
11 changed files with 222 additions and 58 deletions
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53
src/vm/page.c
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@@ -2,18 +2,23 @@
#include <string.h>
#include <stdio.h>
#include "filesys/file.h"
#include "threads/pte.h"
#include "threads/malloc.h"
#include "threads/palloc.h"
#include "userprog/process.h"
#include "userprog/pagedir.h"
#include "vm/frame.h"
#define SWAP_FLAG_BIT 9
#define ADDR_START_BIT 12
/* Hashing function needed for the SPT table. Returns a hash for an entry,
based on its upage. */
unsigned
page_hash (const struct hash_elem *e, UNUSED void *aux)
{
struct page_entry *page = hash_entry (e, struct page_entry, elem);
return hash_ptr(page->upage);
return hash_ptr (page->upage);
}
/* Comparator function for the SPT table. Compares two entries based on their
@@ -71,7 +76,9 @@ page_load (struct page_entry *page, bool writable)
/* Allocate a frame for the page. If a frame allocation fails, then
frame_alloc should try to evict a page. If it is still NULL, the OS
panics as this should not happen if eviction is working correctly. */
void *frame = frame_alloc (PAL_USER, page->upage, thread_current ());
struct thread *t = thread_current ();
void *frame = frame_alloc (PAL_USER, page->upage, t);
pagedir_set_accessed (t->pagedir, page->upage, true);
if (frame == NULL)
PANIC ("Could not allocate a frame to load page into memory.");
@@ -106,3 +113,45 @@ page_cleanup (struct hash_elem *e, void *aux UNUSED)
{
free (hash_entry (e, struct page_entry, elem));
}
/* Updates the 'owner' thread's page table entry for virtual address 'upage'
to flag the page as being stored in swap, and stores the specified swap slot
value in the entry at the address bits for later retrieval from disk. */
void
page_set_swap (struct thread *owner, void *upage, size_t swap_slot)
{
uint32_t *pte = lookup_page (owner->pagedir, upage, false);
/* Store the provided swap slot in the address bits of the page table
entry, truncating excess bits. */
*pte |= (1 << SWAP_FLAG_BIT);
uint32_t swap_slot_bits = (swap_slot << ADDR_START_BIT) & PTE_ADDR;
*pte = (*pte & PTE_FLAGS) | swap_slot_bits;
invalidate_pagedir (owner->pagedir);
}
/* Returns true iff the page with user address 'upage' owned by 'owner'
is flagged to be in the swap disk via the owner's page table. */
bool
page_in_swap (struct thread *owner, void *upage)
{
uint32_t *pte = lookup_page (owner->pagedir, upage, false);
return pte != NULL &&
(*pte & (1 << SWAP_FLAG_BIT)) != 0;
}
/* Given that the page with user address 'upage' owned by 'owner' is flagged
to be in the swap disk via the owner's page table, returns its stored
swap slot. Otherwise panics the kernel. */
size_t
page_get_swap (struct thread *owner, void *upage)
{
uint32_t *pte = lookup_page (owner->pagedir, upage, false);
ASSERT (pte != NULL);
ASSERT ((*pte & PTE_P) == 0);
/* Masks the address bits and returns truncated value. */
return ((*pte & PTE_ADDR) >> ADDR_START_BIT);
}