--- zzzz-none-000/linux-2.6.28.10/mm/filemap.c	2009-05-02 18:54:43.000000000 +0000
+++ puma5-6360-529/linux-2.6.28.10/mm/filemap.c	2010-04-07 09:56:53.000000000 +0000
@@ -486,6 +486,15 @@
 	} else
 		mem_cgroup_uncharge_cache_page(page);
 out:
+#ifdef CONFIG_FUSIV_USB_OPTIMIZATION
+
+        if ( (!(gfp_mask & GFP_ATOMIC )) &&  
+                         (mapping->nrpages > FUSIV_MAX_CACHE_MEM_THRHLD )
+                         && (!(mapping->page_tree.count++%32)))
+        {
+             fusiv_invalidate_mapping_pages(mapping,offset-1);
+        }
+#endif
 	return error;
 }
 EXPORT_SYMBOL(add_to_page_cache_locked);
@@ -1280,6 +1289,9 @@
 }
 EXPORT_SYMBOL(generic_segment_checks);
 
+#ifdef CONFIG_FUSIV_USB_OPTIMIZATION
+void check_and_reduce_unused_page_cache(struct  kiocb *iocb);
+#endif
 /**
  * generic_file_aio_read - generic filesystem read routine
  * @iocb:	kernel I/O control block
@@ -1351,6 +1363,9 @@
 			break;
 	}
 out:
+#ifdef CONFIG_FUSIV_USB_OPTIMIZATION
+          check_and_reduce_unused_page_cache(iocb);
+#endif
 	return retval;
 }
 EXPORT_SYMBOL(generic_file_aio_read);
@@ -2444,6 +2459,9 @@
 		if (err < 0)
 			ret = err;
 	}
+#ifdef CONFIG_FUSIV_USB_OPTIMIZATION
+          check_and_reduce_unused_page_cache(iocb);
+#endif
 	return ret;
 }
 EXPORT_SYMBOL(generic_file_aio_write);