patch-2.3.10 linux/mm/page_alloc.c

• Lines: 91
• Date: Fri Jul 2 15:10:36 1999
• Orig file: v2.3.9/linux/mm/page_alloc.c
• Orig date: Tue Jun 22 10:50:36 1999

diff -u --recursive --new-file v2.3.9/linux/mm/page_alloc.c linux/mm/page_alloc.c
@@ -345,90 +345,3 @@
 	}
 	return start_mem;
 }
-
-/* 
- * Primitive swap readahead code. We simply read an aligned block of
- * (1 << page_cluster) entries in the swap area. This method is chosen
- * because it doesn't cost us any seek time.  We also make sure to queue
- * the 'original' request together with the readahead ones...  
- */
-void swapin_readahead(unsigned long entry)
-{
-	int i;
-	struct page *new_page;
-	unsigned long offset = SWP_OFFSET(entry);
-	struct swap_info_struct *swapdev = SWP_TYPE(entry) + swap_info;
-	
-	offset = (offset >> page_cluster) << page_cluster;
-
-	i = 1 << page_cluster;
-	do {
-		/* Don't read-ahead past the end of the swap area */
-		if (offset >= swapdev->max)
-			break;
-		/* Don't block on I/O for read-ahead */
-		if (atomic_read(&nr_async_pages) >= pager_daemon.swap_cluster)
-			break;
-		/* Don't read in bad or busy pages */
-		if (!swapdev->swap_map[offset])
-			break;
-		if (swapdev->swap_map[offset] == SWAP_MAP_BAD)
-			break;
-
-		/* Ok, do the async read-ahead now */
-		new_page = read_swap_cache_async(SWP_ENTRY(SWP_TYPE(entry), offset), 0);
-		if (new_page != NULL)
-			__free_page(new_page);
-		offset++;
-	} while (--i);
-	return;
-}
-
-/*
- * The tests may look silly, but it essentially makes sure that
- * no other process did a swap-in on us just as we were waiting.
- *
- * Also, don't bother to add to the swap cache if this page-in
- * was due to a write access.
- */
-void swap_in(struct task_struct * tsk, struct vm_area_struct * vma,
-	pte_t * page_table, unsigned long entry, int write_access)
-{
-	unsigned long page;
-	struct page *page_map = lookup_swap_cache(entry);
-
-	if (!page_map) {
-		swapin_readahead(entry);
-		page_map = read_swap_cache(entry);
-	}
-	if (pte_val(*page_table) != entry) {
-		if (page_map)
-			free_page_and_swap_cache(page_address(page_map));
-		return;
-	}
-	if (!page_map) {
-		set_pte(page_table, BAD_PAGE);
-		swap_free(entry);
-		oom(tsk);
-		return;
-	}
-
-	page = page_address(page_map);
-	vma->vm_mm->rss++;
-	tsk->min_flt++;
-	swap_free(entry);
-
-	if (!write_access || is_page_shared(page_map)) {
-		set_pte(page_table, mk_pte(page, vma->vm_page_prot));
-		return;
-	}
-
-	/*
-	 * The page is unshared and we're going to dirty it - so tear
-	 * down the swap cache and give exclusive access to the page to
-	 * this process.
-	 */
-	delete_from_swap_cache(page_map);
-	set_pte(page_table, pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot))));
-  	return;
-}