1 files changed, 123 insertions, 87 deletions

diff --git a/litmus/bank_proc.c b/litmus/bank_proc.c
index 07d572833b30..295c450bfbe2 100644
--- a/litmus/bank_proc.c
+++ b/litmus/bank_proc.c
@@ -1,3 +1,9 @@
+/*
+ * bank_proc.c -- Implementation of the page coloring for cache and bank partition. 
+ *                The file will keep a pool of colored pages. Users can require pages with 
+ *                specific color or bank number.
+ *                Part of the code is modified from Jonathan Herman's code  
+ */
 #include <linux/init.h>
 #include <linux/types.h>
 #include <linux/kernel.h>
@@ -14,16 +20,23 @@
 
 #define LITMUS_LOCKDEP_NAME_MAX_LEN 50
 
-// This is Address Decoding for imx6-sabredsd board
+// This Address Decoding is used in imx6-sabredsd platform
 #define CACHE_MASK 0x0000f000      
 #define BANK_MASK  0x00007000      
 #define OFFSET_SHIFT 12
 
 #define PAGES_PER_COLOR 1024
 
+unsigned long used_cachecolor;
+unsigned long curr_cachecolor;
+
+
 unsigned long number_banks;
 unsigned long number_cachecolors;
 
+/*
+ * Every page list should contain a lock, a list, and a number recording how many pages it store
+ */ 
 struct color_group {
         spinlock_t lock;
         char _lock_name[LITMUS_LOCKDEP_NAME_MAX_LEN];
@@ -31,6 +44,10 @@ struct color_group {
         atomic_t nr_pages;
 };
 
+/*
+ * This is old code which is not used in current version
+ */ 
+/*
 static struct alloced_pages {
         spinlock_t lock;
         struct list_head list;
@@ -41,6 +58,7 @@ struct alloced_page {
         struct vm_area_struct *vma;
         struct list_head list;
 };
+*/
 
 static struct color_group *color_groups;
 static struct lock_class_key color_lock_keys[16];
@@ -59,6 +77,9 @@ static inline unsigned long page_bank(struct page *page)
         return ((page_to_phys(page)& BANK_MASK) >> PAGE_SHIFT);
 }
 
+/*
+ * It is used to determine the smallest number of page lists. 
+ */
 static unsigned long smallest_nr_pages(void)
 {
         unsigned long i, min_pages = -1;
@@ -70,8 +91,9 @@ static unsigned long smallest_nr_pages(void)
         }
         return min_pages;
 }
+
 /*
- * Page's count should be one, it sould not be on any LRU list.
+ * Add a page to current pool.
  */
 void add_page_to_color_list(struct page *page)
 {
@@ -82,22 +104,26 @@ void add_page_to_color_list(struct page *page)
         spin_lock(&cgroup->lock);
         list_add_tail(&page->lru, &cgroup->list);
         atomic_inc(&cgroup->nr_pages);
-//      SetPageLRU(page);
         spin_unlock(&cgroup->lock);
 }
 
+/*
+ * Replenish the page pool. 
+ * If the newly allocate page is what we want, it will be pushed to the correct page list
+ * otherwise, it will be freed. 
+ */
 static int do_add_pages(void)
 {
-        //printk("LITMUS do add pages\n");
+        printk("LITMUS do add pages\n");
         
         struct page *page, *page_tmp;
         LIST_HEAD(free_later);
         unsigned long color;
         int ret = 0;
 
+        // until all the page lists contain enough pages 
         while (smallest_nr_pages() < PAGES_PER_COLOR) {
         
-                //page = alloc_page(GFP_HIGHUSER | __GFP_MOVABLE);
                 page = alloc_page(GFP_HIGHUSER_MOVABLE);
                 
                 if (unlikely(!page)) {
@@ -107,70 +133,79 @@ static int do_add_pages(void)
                 }
                 color = page_color(page);
                 if (atomic_read(&color_groups[color].nr_pages) < PAGES_PER_COLOR) {
-        //              SetPageReserved(page);
                         add_page_to_color_list(page);
-                } else
+                } else{
+                        // Pages here will be freed later 
                         list_add_tail(&page->lru, &free_later);
+                }
         }
+        // Free the unwanted pages
         list_for_each_entry_safe(page, page_tmp, &free_later, lru) {
                 list_del(&page->lru);
                 __free_page(page);
         }
-        /* setup the color queue stuff */
-//      ret = setup_flusher_array();
 out:
         return ret;
 }
 
-extern int l2_usable_sets;
+/*
+ * Provide pages for replacement according cache color 
+ * This should be the only implementation here
+ * This function should not be accessed by others directly. 
+ * 
+ */ 
+static struct  page *new_alloc_page_color( unsigned long color)
+{
+        printk("allocate new page color = %d\n", color);        
+        struct color_group *cgroup;
+        struct page *rPage = NULL;
+                
+        if( (color <0) || (color)>15) {
+                TRACE_CUR("Wrong color %lu\n", color);  
+                printk(KERN_WARNING "Wrong color %lu\n", color);
+                goto out_unlock;
+        }
+
+                
+        cgroup = &color_groups[color];
+        spin_lock(&cgroup->lock);
+        if (unlikely(!atomic_read(&cgroup->nr_pages))) {
+                TRACE_CUR("No free %lu colored pages.\n", color);
+                printk(KERN_WARNING "no free %lu colored pages.\n", color);
+                goto out_unlock;
+        }
+        rPage = list_first_entry(&cgroup->list, struct page, lru);
+        BUG_ON(page_count(rPage) > 1);
+        get_page(rPage);
+        list_del(&rPage->lru);
+        atomic_dec(&cgroup->nr_pages);
+//      ClearPageLRU(rPage);
+out_unlock:
+        spin_unlock(&cgroup->lock);
+out:
+        do_add_pages();
+        return rPage;
+}
+
 
 /*
- * provide pages for replacement 
+ * provide pages for replacement according to  
  * node = 0 for Level A, B tasks in Cpu 0
  * node = 1 for Level A, B tasks in Cpu 1
  * node = 2 for Level A, B tasks in Cpu 2
  * node = 3 for Level A, B tasks in Cpu 3
  * node = 4 for Level C tasks 
  */
-#if 1
 struct page *new_alloc_page(struct page *page, unsigned long node, int **x)
 {
-        //printk("allocate new page node = %d\n", node);        
+        printk("allocate new page node = %d\n", node);  
 //      return alloc_pages_exact_node(node, GFP_HIGHUSER_MOVABLE, 0);
         struct color_group *cgroup;
         struct page *rPage = NULL;
         unsigned int color;
         get_random_bytes(&color, sizeof(unsigned int));
         
-        /*
-        if(node ==0){
-                color = (color%2)*8+node;
-        }else if(node == 1){
-                color = (color%2)*8+node;
-        }else if(node == 2){
-                color = (color%2)*8+;
-        }else if(node == 3){
-                color = color%2 + 6;
-        }else if(node == 4){
-                color = color%8 + 8;
-        }else{
-                goto out;
-        }
-        */
-        switch(node ){
-                case 0:
-                        color = (color % l2_usable_sets);
-                        break;
-                case 1: 
-                case 2: 
-                case 3:
-                case 4:
-                        color = (color% (16-l2_usable_sets)) + l2_usable_sets;
-                        break;
-                default:
-                        goto out;
-        }
-        /*
+        // Decode the node to decide what color pages we should provide
         switch(node ){
                 case 0:
                 case 1: 
@@ -184,34 +219,22 @@ struct page *new_alloc_page(struct page *page, unsigned long node, int **x)
                                 color+=4;
                         break;
                 default:
-                        goto out;
+                        TRACE_CUR("Wrong color %lu\n", color);  
+                        printk(KERN_WARNING "Wrong color %lu\n", color);
+                        return rPage;
         }
-        */
 
-        //printk("allocate new page color = %d\n", color);
-        //TRACE("allocate new page color = %d\n", color);
+
+        printk("allocate new page color = %d\n", color);
                 
-        cgroup = &color_groups[color];
-        spin_lock(&cgroup->lock);
-        if (unlikely(!atomic_read(&cgroup->nr_pages))) {
-                //TRACE_CUR("No free %lu colored pages.\n", color);
-                printk(KERN_WARNING "no free %lu colored pages.\n", color);
-                goto out_unlock;
-        }
-        rPage = list_first_entry(&cgroup->list, struct page, lru);
-        BUG_ON(page_count(rPage) > 1);
-        get_page(rPage);
-        list_del(&rPage->lru);
-        atomic_dec(&cgroup->nr_pages);
-//      ClearPageLRU(rPage);
-out_unlock:
-        spin_unlock(&cgroup->lock);
-out:
-        do_add_pages();
-        return rPage;
+        rPage =  new_alloc_page_color(color);
+        return rPage; 
 }
-#endif
 
+/*
+ * Provide pages for replacement according to bank number. 
+ * This is used in cache way partition 
+ */
 struct page *new_alloc_page_banknr(struct page *page, unsigned long banknr, int **x)
 {
         printk("allocate new page bank = %d\n", banknr);        
@@ -225,30 +248,43 @@ struct page *new_alloc_page_banknr(struct page *page, unsigned long banknr, int
         }else{
                 goto out;
         }
+        
+        rPage =  new_alloc_page_color(color);
                 
-        cgroup = &color_groups[color];
-        spin_lock(&cgroup->lock);
-        if (unlikely(!atomic_read(&cgroup->nr_pages))) {
-                TRACE_CUR("No free %lu colored pages.\n", color);
-                printk(KERN_WARNING "no free %lu colored pages.\n", color);
-                goto out_unlock;
-        }
-        rPage = list_first_entry(&cgroup->list, struct page, lru);
-        BUG_ON(page_count(rPage) > 1);
-        get_page(rPage);
-        list_del(&rPage->lru);
-        atomic_dec(&cgroup->nr_pages);
-//      ClearPageLRU(rPage);
-out_unlock:
-        spin_unlock(&cgroup->lock);
 out:
-        do_add_pages();
         return rPage;
+}
 
 
+void set_number_of_colors(unsigned long colornr)
+{
+        used_cachecolor = colornr ; 
+        curr_cachecolor = 0;
+}
+
 
+/*
+ * Provide pages for replacement 
+ * This is used to generate experiments 
+ */
+struct page *new_alloc_page_predefined(struct page *page,  int **x)
+{
+        unsigned int color = curr_cachecolor; 
+        
+        printk("allocate new page color = %d\n", color);        
+        struct color_group *cgroup;
+        struct page *rPage = NULL;
+        
+        rPage =  new_alloc_page_color(color);
+        color = (color + 1)% used_cachecolor;
+out:
+        return rPage;
 }
 
+
+/*
+ * Initialize the numbers of banks and cache colors 
+ */ 
 static int __init init_variables(void)
 {
         number_banks = 1+(BANK_MASK >> PAGE_SHIFT); 
@@ -256,7 +292,9 @@ static int __init init_variables(void)
 }
 
 
-
+/*
+ * Initialize the page pool 
+ */
 static int __init init_color_groups(void)
 {
         struct color_group *cgroup;
@@ -275,22 +313,20 @@ static int __init init_color_groups(void)
                         atomic_set(&cgroup->nr_pages, 0);
                         INIT_LIST_HEAD(&cgroup->list);
                         spin_lock_init(&cgroup->lock);
-//                      LOCKDEP_DYNAMIC_ALLOC(&cgroup->lock, &color_lock_keys[i],
-//                                      cgroup->_lock_name, "color%lu", i);
                 }
         }
         return err;
 }
 
 /*
- * Initialzie the this proc 
+ * Initialzie this proc 
  */
 static int __init litmus_color_init(void)
 {
         int err=0;
         
-        INIT_LIST_HEAD(&alloced_pages.list);
-        spin_lock_init(&alloced_pages.lock);
+        //INIT_LIST_HEAD(&alloced_pages.list);
+        //spin_lock_init(&alloced_pages.lock);
         init_variables();
         printk("Cache number = %d , Cache mask = 0x%lx\n", number_cachecolors, CACHE_MASK); 
         printk("Bank number = %d , Bank mask = 0x%lx\n", number_banks, BANK_MASK);