KVM: VMX: Use INTR_TYPE_NMI_INTR instead of magic value
[safe/jmp/linux-2.6] / mm / page-writeback.c
index c689b60..2970e35 100644 (file)
@@ -7,7 +7,7 @@
  * Contains functions related to writing back dirty pages at the
  * address_space level.
  *
- * 10Apr2002   akpm@zip.com.au
+ * 10Apr2002   Andrew Morton
  *             Initial version
  */
 
@@ -126,8 +126,6 @@ static void background_writeout(unsigned long _min_pages);
 static struct prop_descriptor vm_completions;
 static struct prop_descriptor vm_dirties;
 
-static unsigned long determine_dirtyable_memory(void);
-
 /*
  * couple the period to the dirty_ratio:
  *
@@ -164,8 +162,19 @@ int dirty_ratio_handler(struct ctl_table *table, int write,
  */
 static inline void __bdi_writeout_inc(struct backing_dev_info *bdi)
 {
-       __prop_inc_percpu(&vm_completions, &bdi->completions);
+       __prop_inc_percpu_max(&vm_completions, &bdi->completions,
+                             bdi->max_prop_frac);
+}
+
+void bdi_writeout_inc(struct backing_dev_info *bdi)
+{
+       unsigned long flags;
+
+       local_irq_save(flags);
+       __bdi_writeout_inc(bdi);
+       local_irq_restore(flags);
 }
+EXPORT_SYMBOL_GPL(bdi_writeout_inc);
 
 static inline void task_dirty_inc(struct task_struct *tsk)
 {
@@ -200,7 +209,8 @@ clip_bdi_dirty_limit(struct backing_dev_info *bdi, long dirty, long *pbdi_dirty)
        avail_dirty = dirty -
                (global_page_state(NR_FILE_DIRTY) +
                 global_page_state(NR_WRITEBACK) +
-                global_page_state(NR_UNSTABLE_NFS));
+                global_page_state(NR_UNSTABLE_NFS) +
+                global_page_state(NR_WRITEBACK_TEMP));
 
        if (avail_dirty < 0)
                avail_dirty = 0;
@@ -243,6 +253,55 @@ static void task_dirty_limit(struct task_struct *tsk, long *pdirty)
 }
 
 /*
+ *
+ */
+static DEFINE_SPINLOCK(bdi_lock);
+static unsigned int bdi_min_ratio;
+
+int bdi_set_min_ratio(struct backing_dev_info *bdi, unsigned int min_ratio)
+{
+       int ret = 0;
+       unsigned long flags;
+
+       spin_lock_irqsave(&bdi_lock, flags);
+       if (min_ratio > bdi->max_ratio) {
+               ret = -EINVAL;
+       } else {
+               min_ratio -= bdi->min_ratio;
+               if (bdi_min_ratio + min_ratio < 100) {
+                       bdi_min_ratio += min_ratio;
+                       bdi->min_ratio += min_ratio;
+               } else {
+                       ret = -EINVAL;
+               }
+       }
+       spin_unlock_irqrestore(&bdi_lock, flags);
+
+       return ret;
+}
+
+int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned max_ratio)
+{
+       unsigned long flags;
+       int ret = 0;
+
+       if (max_ratio > 100)
+               return -EINVAL;
+
+       spin_lock_irqsave(&bdi_lock, flags);
+       if (bdi->min_ratio > max_ratio) {
+               ret = -EINVAL;
+       } else {
+               bdi->max_ratio = max_ratio;
+               bdi->max_prop_frac = (PROP_FRAC_BASE * max_ratio) / 100;
+       }
+       spin_unlock_irqrestore(&bdi_lock, flags);
+
+       return ret;
+}
+EXPORT_SYMBOL(bdi_set_max_ratio);
+
+/*
  * Work out the current dirty-memory clamping and background writeout
  * thresholds.
  *
@@ -270,9 +329,7 @@ static unsigned long highmem_dirtyable_memory(unsigned long total)
                struct zone *z =
                        &NODE_DATA(node)->node_zones[ZONE_HIGHMEM];
 
-               x += zone_page_state(z, NR_FREE_PAGES)
-                       + zone_page_state(z, NR_INACTIVE)
-                       + zone_page_state(z, NR_ACTIVE);
+               x += zone_page_state(z, NR_FREE_PAGES) + zone_lru_pages(z);
        }
        /*
         * Make sure that the number of highmem pages is never larger
@@ -286,13 +343,17 @@ static unsigned long highmem_dirtyable_memory(unsigned long total)
 #endif
 }
 
-static unsigned long determine_dirtyable_memory(void)
+/**
+ * determine_dirtyable_memory - amount of memory that may be used
+ *
+ * Returns the numebr of pages that can currently be freed and used
+ * by the kernel for direct mappings.
+ */
+unsigned long determine_dirtyable_memory(void)
 {
        unsigned long x;
 
-       x = global_page_state(NR_FREE_PAGES)
-               + global_page_state(NR_INACTIVE)
-               + global_page_state(NR_ACTIVE);
+       x = global_page_state(NR_FREE_PAGES) + global_lru_pages();
 
        if (!vm_highmem_is_dirtyable)
                x -= highmem_dirtyable_memory(x);
@@ -300,7 +361,7 @@ static unsigned long determine_dirtyable_memory(void)
        return x + 1;   /* Ensure that we never return 0 */
 }
 
-static void
+void
 get_dirty_limits(long *pbackground, long *pdirty, long *pbdi_dirty,
                 struct backing_dev_info *bdi)
 {
@@ -330,7 +391,7 @@ get_dirty_limits(long *pbackground, long *pdirty, long *pbdi_dirty,
        *pdirty = dirty;
 
        if (bdi) {
-               u64 bdi_dirty = dirty;
+               u64 bdi_dirty;
                long numerator, denominator;
 
                /*
@@ -338,8 +399,12 @@ get_dirty_limits(long *pbackground, long *pdirty, long *pbdi_dirty,
                 */
                bdi_writeout_fraction(bdi, &numerator, &denominator);
 
+               bdi_dirty = (dirty * (100 - bdi_min_ratio)) / 100;
                bdi_dirty *= numerator;
                do_div(bdi_dirty, denominator);
+               bdi_dirty += (dirty * bdi->min_ratio) / 100;
+               if (bdi_dirty > (dirty * bdi->max_ratio) / 100)
+                       bdi_dirty = dirty * bdi->max_ratio / 100;
 
                *pbdi_dirty = bdi_dirty;
                clip_bdi_dirty_limit(bdi, dirty, pbdi_dirty);
@@ -567,6 +632,7 @@ static void background_writeout(unsigned long _min_pages)
                        global_page_state(NR_UNSTABLE_NFS) < background_thresh
                                && min_pages <= 0)
                        break;
+               wbc.more_io = 0;
                wbc.encountered_congestion = 0;
                wbc.nr_to_write = MAX_WRITEBACK_PAGES;
                wbc.pages_skipped = 0;
@@ -574,8 +640,9 @@ static void background_writeout(unsigned long _min_pages)
                min_pages -= MAX_WRITEBACK_PAGES - wbc.nr_to_write;
                if (wbc.nr_to_write > 0 || wbc.pages_skipped > 0) {
                        /* Wrote less than expected */
-                       congestion_wait(WRITE, HZ/10);
-                       if (!wbc.encountered_congestion)
+                       if (wbc.encountered_congestion || wbc.more_io)
+                               congestion_wait(WRITE, HZ/10);
+                       else
                                break;
                }
        }
@@ -640,11 +707,12 @@ static void wb_kupdate(unsigned long arg)
                        global_page_state(NR_UNSTABLE_NFS) +
                        (inodes_stat.nr_inodes - inodes_stat.nr_unused);
        while (nr_to_write > 0) {
+               wbc.more_io = 0;
                wbc.encountered_congestion = 0;
                wbc.nr_to_write = MAX_WRITEBACK_PAGES;
                writeback_inodes(&wbc);
                if (wbc.nr_to_write > 0) {
-                       if (wbc.encountered_congestion)
+                       if (wbc.encountered_congestion || wbc.more_io)
                                congestion_wait(WRITE, HZ/10);
                        else
                                break;  /* All the old data is written */
@@ -804,6 +872,7 @@ int write_cache_pages(struct address_space *mapping,
        pgoff_t end;            /* Inclusive */
        int scanned = 0;
        int range_whole = 0;
+       long nr_to_write = wbc->nr_to_write;
 
        if (wbc->nonblocking && bdi_write_congested(bdi)) {
                wbc->encountered_congestion = 1;
@@ -867,7 +936,7 @@ retry:
                                unlock_page(page);
                                ret = 0;
                        }
-                       if (ret || (--(wbc->nr_to_write) <= 0))
+                       if (ret || (--nr_to_write <= 0))
                                done = 1;
                        if (wbc->nonblocking && bdi_write_congested(bdi)) {
                                wbc->encountered_congestion = 1;
@@ -886,8 +955,12 @@ retry:
                index = 0;
                goto retry;
        }
-       if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
-               mapping->writeback_index = index;
+       if (!wbc->no_nrwrite_index_update) {
+               if (wbc->range_cyclic || (range_whole && nr_to_write > 0))
+                       mapping->writeback_index = index;
+               wbc->nr_to_write = nr_to_write;
+       }
+
        return ret;
 }
 EXPORT_SYMBOL(write_cache_pages);
@@ -1013,7 +1086,7 @@ int __set_page_dirty_nobuffers(struct page *page)
                if (!mapping)
                        return 1;
 
-               write_lock_irq(&mapping->tree_lock);
+               spin_lock_irq(&mapping->tree_lock);
                mapping2 = page_mapping(page);
                if (mapping2) { /* Race with truncate? */
                        BUG_ON(mapping2 != mapping);
@@ -1027,7 +1100,7 @@ int __set_page_dirty_nobuffers(struct page *page)
                        radix_tree_tag_set(&mapping->page_tree,
                                page_index(page), PAGECACHE_TAG_DIRTY);
                }
-               write_unlock_irq(&mapping->tree_lock);
+               spin_unlock_irq(&mapping->tree_lock);
                if (mapping->host) {
                        /* !PageAnon && !swapper_space */
                        __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
@@ -1073,7 +1146,7 @@ static int __set_page_dirty(struct page *page)
        return 0;
 }
 
-int fastcall set_page_dirty(struct page *page)
+int set_page_dirty(struct page *page)
 {
        int ret = __set_page_dirty(page);
        if (ret)
@@ -1183,18 +1256,18 @@ int test_clear_page_writeback(struct page *page)
                struct backing_dev_info *bdi = mapping->backing_dev_info;
                unsigned long flags;
 
-               write_lock_irqsave(&mapping->tree_lock, flags);
+               spin_lock_irqsave(&mapping->tree_lock, flags);
                ret = TestClearPageWriteback(page);
                if (ret) {
                        radix_tree_tag_clear(&mapping->page_tree,
                                                page_index(page),
                                                PAGECACHE_TAG_WRITEBACK);
-                       if (bdi_cap_writeback_dirty(bdi)) {
+                       if (bdi_cap_account_writeback(bdi)) {
                                __dec_bdi_stat(bdi, BDI_WRITEBACK);
                                __bdi_writeout_inc(bdi);
                        }
                }
-               write_unlock_irqrestore(&mapping->tree_lock, flags);
+               spin_unlock_irqrestore(&mapping->tree_lock, flags);
        } else {
                ret = TestClearPageWriteback(page);
        }
@@ -1212,20 +1285,20 @@ int test_set_page_writeback(struct page *page)
                struct backing_dev_info *bdi = mapping->backing_dev_info;
                unsigned long flags;
 
-               write_lock_irqsave(&mapping->tree_lock, flags);
+               spin_lock_irqsave(&mapping->tree_lock, flags);
                ret = TestSetPageWriteback(page);
                if (!ret) {
                        radix_tree_tag_set(&mapping->page_tree,
                                                page_index(page),
                                                PAGECACHE_TAG_WRITEBACK);
-                       if (bdi_cap_writeback_dirty(bdi))
+                       if (bdi_cap_account_writeback(bdi))
                                __inc_bdi_stat(bdi, BDI_WRITEBACK);
                }
                if (!PageDirty(page))
                        radix_tree_tag_clear(&mapping->page_tree,
                                                page_index(page),
                                                PAGECACHE_TAG_DIRTY);
-               write_unlock_irqrestore(&mapping->tree_lock, flags);
+               spin_unlock_irqrestore(&mapping->tree_lock, flags);
        } else {
                ret = TestSetPageWriteback(page);
        }