diff -urN 2.4.19pre5/drivers/block/ll_rw_blk.c lowlat/drivers/block/ll_rw_blk.c
--- 2.4.19pre5/drivers/block/ll_rw_blk.c	Sat Mar 30 00:11:54 2002
+++ lowlat/drivers/block/ll_rw_blk.c	Sat Mar 30 20:58:33 2002
@@ -1000,6 +1000,7 @@
 			kstat.pgpgin += count;
 			break;
 	}
+	conditional_schedule();
 }
 
 /**
diff -urN 2.4.19pre5/fs/buffer.c lowlat/fs/buffer.c
--- 2.4.19pre5/fs/buffer.c	Sat Mar 30 00:12:03 2002
+++ lowlat/fs/buffer.c	Sat Mar 30 20:58:33 2002
@@ -219,6 +219,8 @@
 				continue;
 
 			spin_unlock(&lru_list_lock);
+			conditional_schedule();
+
 			write_locked_buffers(array, count);
 			return -EAGAIN;
 		}
@@ -226,6 +228,7 @@
 		__refile_buffer(bh);
 	}
 	spin_unlock(&lru_list_lock);
+	conditional_schedule();
 
 	if (count)
 		write_locked_buffers(array, count);
@@ -271,17 +274,19 @@
 		spin_unlock(&lru_list_lock);
 		wait_on_buffer (bh);
 		put_bh(bh);
+		conditional_schedule();
 		return -EAGAIN;
 	}
 	spin_unlock(&lru_list_lock);
+	conditional_schedule();
 	return 0;
 }
 
 static int wait_for_locked_buffers(kdev_t dev, int index, int refile)
 {
-	do {
+	do
 		spin_lock(&lru_list_lock);
-	} while (wait_for_buffers(dev, index, refile));
+	while (wait_for_buffers(dev, index, refile));
 	return 0;
 }
 
@@ -1027,6 +1032,7 @@
 	for (;;) {
 		struct buffer_head * bh;
 
+		conditional_schedule();
 		bh = get_hash_table(dev, block, size);
 		if (bh)
 			return bh;
diff -urN 2.4.19pre5/fs/dcache.c lowlat/fs/dcache.c
--- 2.4.19pre5/fs/dcache.c	Mon Feb 25 22:05:08 2002
+++ lowlat/fs/dcache.c	Sat Mar 30 20:58:33 2002
@@ -71,7 +71,7 @@
  * d_iput() operation if defined.
  * Called with dcache_lock held, drops it.
  */
-static inline void dentry_iput(struct dentry * dentry)
+static void dentry_iput(struct dentry * dentry)
 {
 	struct inode *inode = dentry->d_inode;
 	if (inode) {
@@ -84,6 +84,7 @@
 			iput(inode);
 	} else
 		spin_unlock(&dcache_lock);
+	conditional_schedule();
 }
 
 /* 
diff -urN 2.4.19pre5/fs/jbd/commit.c lowlat/fs/jbd/commit.c
--- 2.4.19pre5/fs/jbd/commit.c	Mon Feb 25 22:05:08 2002
+++ lowlat/fs/jbd/commit.c	Sat Mar 30 20:58:33 2002
@@ -212,6 +212,16 @@
 				__journal_remove_journal_head(bh);
 				refile_buffer(bh);
 				__brelse(bh);
+				if (current->need_resched) {
+					if (commit_transaction->t_sync_datalist)
+						commit_transaction->t_sync_datalist =
+							next_jh;
+					if (bufs)
+						break;
+					spin_unlock(&journal_datalist_lock);
+					conditional_schedule();
+					goto write_out_data;
+				}
 			}
 		}
 		if (bufs == ARRAY_SIZE(wbuf)) {
diff -urN 2.4.19pre5/fs/proc/array.c lowlat/fs/proc/array.c
--- 2.4.19pre5/fs/proc/array.c	Tue Jan 22 18:54:59 2002
+++ lowlat/fs/proc/array.c	Sat Mar 30 20:58:33 2002
@@ -415,6 +415,8 @@
 		pte_t page = *pte;
 		struct page *ptpage;
 
+		conditional_schedule();
+
 		address += PAGE_SIZE;
 		pte++;
 		if (pte_none(page))
diff -urN 2.4.19pre5/fs/proc/generic.c lowlat/fs/proc/generic.c
--- 2.4.19pre5/fs/proc/generic.c	Tue Jan 22 18:53:53 2002
+++ lowlat/fs/proc/generic.c	Sat Mar 30 20:58:33 2002
@@ -98,7 +98,9 @@
 				retval = n;
 			break;
 		}
-		
+
+		conditional_schedule();
+
 		/* This is a hack to allow mangling of file pos independent
  		 * of actual bytes read.  Simply place the data at page,
  		 * return the bytes, and set `start' to the desired offset
diff -urN 2.4.19pre5/include/linux/condsched.h lowlat/include/linux/condsched.h
--- 2.4.19pre5/include/linux/condsched.h	Thu Jan  1 01:00:00 1970
+++ lowlat/include/linux/condsched.h	Sat Mar 30 20:58:33 2002
@@ -0,0 +1,14 @@
+#ifndef _LINUX_CONDSCHED_H
+#define _LINUX_CONDSCHED_H
+
+#ifndef __ASSEMBLY__
+#define conditional_schedule() \
+do { \
+	if (unlikely(current->need_resched)) { \
+		__set_current_state(TASK_RUNNING); \
+		schedule(); \
+	} \
+} while(0)
+#endif
+
+#endif
diff -urN 2.4.19pre5/include/linux/sched.h lowlat/include/linux/sched.h
--- 2.4.19pre5/include/linux/sched.h	Sat Mar 30 00:12:05 2002
+++ lowlat/include/linux/sched.h	Sat Mar 30 20:58:33 2002
@@ -13,6 +13,7 @@
 #include <linux/times.h>
 #include <linux/timex.h>
 #include <linux/rbtree.h>
+#include <linux/condsched.h>
 
 #include <asm/system.h>
 #include <asm/semaphore.h>
diff -urN 2.4.19pre5/mm/filemap.c lowlat/mm/filemap.c
--- 2.4.19pre5/mm/filemap.c	Sat Mar 30 00:12:05 2002
+++ lowlat/mm/filemap.c	Sat Mar 30 20:58:33 2002
@@ -295,11 +295,7 @@
 
 			page_cache_release(page);
 
-			if (current->need_resched) {
-				__set_current_state(TASK_RUNNING);
-				schedule();
-			}
-
+			conditional_schedule();
 			spin_lock(&pagecache_lock);
 			goto restart;
 		}
@@ -405,11 +401,8 @@
 		}
 
 		page_cache_release(page);
-		if (current->need_resched) {
-			__set_current_state(TASK_RUNNING);
-			schedule();
-		}
 
+		conditional_schedule();
 		spin_lock(&pagecache_lock);
 		goto restart;
 	}
@@ -699,6 +692,8 @@
 	struct page **hash = page_hash(mapping, offset);
 	struct page *page; 
 
+	conditional_schedule();
+
 	spin_lock(&pagecache_lock);
 	page = __find_page_nolock(mapping, offset, *hash);
 	spin_unlock(&pagecache_lock);
@@ -1432,6 +1427,9 @@
 		offset &= ~PAGE_CACHE_MASK;
 
 		page_cache_release(page);
+
+		conditional_schedule();
+
 		if (ret == nr && desc->count)
 			continue;
 		break;
@@ -3092,6 +3090,8 @@
 		SetPageReferenced(page);
 		UnlockPage(page);
 		page_cache_release(page);
+
+		conditional_schedule();
 
 		if (status < 0)
 			break;