Index: linux-2.6.8.1/fs/dcache.c
===================================================================
--- linux-2.6.8.1.orig/fs/dcache.c	2004-08-17 15:22:45.893155591 +1000
+++ linux-2.6.8.1/fs/dcache.c	2004-08-17 15:24:37.503327400 +1000
@@ -379,6 +379,11 @@ static void prune_dcache(int count)
 		struct dentry *dentry;
 		struct list_head *tmp;
 
+		if (unlikely((count & 255) == 0)) {
+			spin_unlock(&dcache_lock);
+			cpu_relax();
+			spin_lock(&dcache_lock);
+		}
 		tmp = dentry_unused.prev;
 		if (tmp == &dentry_unused)
 			break;
Index: linux-2.6.8.1/fs/jbd/checkpoint.c
===================================================================
--- linux-2.6.8.1.orig/fs/jbd/checkpoint.c	2004-08-17 15:22:47.604881807 +1000
+++ linux-2.6.8.1/fs/jbd/checkpoint.c	2004-08-17 15:24:36.636465698 +1000
@@ -132,6 +132,7 @@ static int __cleanup_transaction(journal
 {
 	struct journal_head *jh, *next_jh, *last_jh;
 	struct buffer_head *bh;
+	unsigned char nr_buffers = 1;
 	int ret = 0;
 
 	assert_spin_locked(&journal->j_list_lock);
@@ -185,9 +186,15 @@ static int __cleanup_transaction(journal
 			journal_remove_journal_head(bh);
 			__brelse(bh);
 			ret = 1;
+			nr_buffers++;
 		} else {
 			jbd_unlock_bh_state(bh);
 		}
+		if (nr_buffers == 0) {
+			spin_lock(&journal->j_list_lock);
+			cpu_relax();
+			goto out_return_1;
+		}
 		jh = next_jh;
 	} while (jh != last_jh);
 
@@ -455,9 +462,8 @@ int cleanup_journal_tail(journal_t *jour
  *
  * Find all the written-back checkpoint buffers in the journal and release them.
  *
- * Called with the journal locked.
- * Called with j_list_lock held.
- * Returns number of bufers reaped (for debug)
+ * Called with j_list_lock held, drops it.
+ * Returns number of bufers reaped
  */
 
 int __journal_clean_checkpoint_list(journal_t *journal)
@@ -467,7 +473,7 @@ int __journal_clean_checkpoint_list(jour
 
 	transaction = journal->j_checkpoint_transactions;
 	if (transaction == 0)
-		goto out;
+		goto out_unlock;
 
 	last_transaction = transaction->t_cpprev;
 	next_transaction = transaction;
@@ -484,13 +490,41 @@ int __journal_clean_checkpoint_list(jour
 			do {
 				jh = next_jh;
 				next_jh = jh->b_cpnext;
-				/* Use trylock because of the ranknig */
+				/* Use trylock because of the ranking */
 				if (jbd_trylock_bh_state(jh2bh(jh)))
 					ret += __try_to_free_cp_buf(jh);
 			} while (jh != last_jh);
 		}
+#ifdef CONFIG_PREEMPT
+		/*
+		 * This is potentially sucky: semi-quadratic performance if
+		 * there are a lot of dirty buffers.  So only do it if the user
+		 * has chosen a preemptible kernel.  If !CONFIG_PREEMPT we're
+		 * optimimising for straight-line performance, after all.
+		 * We don't test cond_resched() here because another CPU could
+		 * be waiting on j_list_lock() while holding a different lock.
+		 */
+		if ((ret & 127) == 127) {
+			spin_unlock(&journal->j_list_lock);
+			/*
+			 * We need to schedule away.  Rotate both this
+			 * transaction's buffer list and the checkpoint list to
+			 * try to avoid quadratic behaviour.
+			 */
+			jh = transaction->t_checkpoint_list;
+			if (jh)
+				transaction->t_checkpoint_list = jh->b_cpnext;
+
+			transaction = journal->j_checkpoint_transactions;
+			if (transaction)
+				journal->j_checkpoint_transactions =
+					transaction->t_cpnext;
+			return ret;
+		}
+#endif
 	} while (transaction != last_transaction);
-out:
+out_unlock:
+	spin_unlock(&journal->j_list_lock);
 	return ret;
 }
 
Index: linux-2.6.8.1/fs/jbd/commit.c
===================================================================
--- linux-2.6.8.1.orig/fs/jbd/commit.c	2004-08-17 15:22:46.321087144 +1000
+++ linux-2.6.8.1/fs/jbd/commit.c	2004-08-17 15:24:37.061397905 +1000
@@ -114,6 +114,7 @@ void journal_commit_transaction(journal_
 	int space_left = 0;
 	int first_tag = 0;
 	int tag_flag;
+	int nr_buffers = 0;
 	int i;
 
 	/*
@@ -208,9 +209,16 @@ void journal_commit_transaction(journal_
 	 * checkpoint lists.  We do this *before* commit because it potentially
 	 * frees some memory
 	 */
-	spin_lock(&journal->j_list_lock);
-	__journal_clean_checkpoint_list(journal);
-	spin_unlock(&journal->j_list_lock);
+	spin_unlock(&journal->j_state_lock);
+	{
+		int nr_cleaned;
+
+		do {
+			spin_lock(&journal->j_list_lock);
+			nr_cleaned = __journal_clean_checkpoint_list(journal);
+		} while (nr_cleaned);
+	}
+	spin_lock(&journal->j_state_lock);
 
 	jbd_debug (3, "JBD: commit phase 1\n");
 
@@ -262,8 +270,10 @@ write_out_data:
 			__journal_file_buffer(jh, commit_transaction,
 						BJ_Locked);
 			jbd_unlock_bh_state(bh);
-			if (need_resched()) {
+			nr_buffers++;
+			if ((nr_buffers & 15) == 0 || need_resched()) {
 				spin_unlock(&journal->j_list_lock);
+				cpu_relax();
 				goto write_out_data;
 			}
 		} else {
@@ -288,8 +298,10 @@ write_out_data:
 				jbd_unlock_bh_state(bh);
 				journal_remove_journal_head(bh);
 				put_bh(bh);
-				if (need_resched()) {
+				nr_buffers++;
+				if ((nr_buffers & 15) == 0 || need_resched()) {
 					spin_unlock(&journal->j_list_lock);
+					cpu_relax();
 					goto write_out_data;
 				}
 			}
@@ -333,7 +345,8 @@ write_out_data:
 			jbd_unlock_bh_state(bh);
 		}
 		put_bh(bh);
-		if (need_resched()) {
+		nr_buffers++;
+		if ((nr_buffers & 15) == 0 || need_resched()) {
 			spin_unlock(&journal->j_list_lock);
 			cond_resched();
 			spin_lock(&journal->j_list_lock);
Index: linux-2.6.8.1/fs/jbd/recovery.c
===================================================================
--- linux-2.6.8.1.orig/fs/jbd/recovery.c	2004-08-17 15:22:46.423070832 +1000
+++ linux-2.6.8.1/fs/jbd/recovery.c	2004-08-17 15:24:36.109549763 +1000
@@ -354,6 +354,8 @@ static int do_one_pass(journal_t *journa
 		struct buffer_head *	obh;
 		struct buffer_head *	nbh;
 
+		cond_resched();		/* We're under lock_kernel() */
+
 		/* If we already know where to stop the log traversal,
 		 * check right now that we haven't gone past the end of
 		 * the log. */
Index: linux-2.6.8.1/mm/memory.c
===================================================================
--- linux-2.6.8.1.orig/mm/memory.c	2004-08-17 15:24:32.320154356 +1000
+++ linux-2.6.8.1/mm/memory.c	2004-08-17 15:24:38.823116847 +1000
@@ -567,12 +567,15 @@ int unmap_vmas(struct mmu_gather **tlbp,
 			zap_bytes -= block;
 			if ((long)zap_bytes > 0)
 				continue;
-			if (!atomic && need_resched()) {
+			if (!atomic) {
 				int fullmm = tlb_is_full_mm(*tlbp);
+
 				tlb_finish_mmu(*tlbp, tlb_start, start);
-				cond_resched_lock(&mm->page_table_lock);
-				*tlbp = tlb_gather_mmu(mm, fullmm);
+				spin_unlock(&mm->page_table_lock);
+				cond_resched();
 				tlb_start_valid = 0;
+				spin_lock(&mm->page_table_lock);
+				*tlbp = tlb_gather_mmu(mm, fullmm);
 			}
 			zap_bytes = ZAP_BLOCK_SIZE;
 		}
Index: linux-2.6.8.1/mm/msync.c
===================================================================
--- linux-2.6.8.1.orig/mm/msync.c	2004-08-17 15:22:47.084964964 +1000
+++ linux-2.6.8.1/mm/msync.c	2004-08-17 15:24:35.532641805 +1000
@@ -92,8 +92,8 @@ static inline int filemap_sync_pmd_range
 	return error;
 }
 
-static int filemap_sync(struct vm_area_struct * vma, unsigned long address,
-	size_t size, unsigned int flags)
+static int __filemap_sync(struct vm_area_struct *vma, unsigned long address,
+			size_t size, unsigned int flags)
 {
 	pgd_t * dir;
 	unsigned long end = address + size;
@@ -131,6 +131,30 @@ static int filemap_sync(struct vm_area_s
 	return error;
 }
 
+#ifdef CONFIG_PREEMPT
+static int filemap_sync(struct vm_area_struct *vma, unsigned long address,
+			size_t size, unsigned int flags)
+{
+	const size_t chunk = 64 * 1024;	/* bytes */
+	int error = 0;
+
+	while (size) {
+		size_t sz = min(size, chunk);
+
+		error |= __filemap_sync(vma, address, sz, flags);
+		address += sz;
+		size -= sz;
+	}
+	return error;
+}
+#else
+static int filemap_sync(struct vm_area_struct *vma, unsigned long address,
+			size_t size, unsigned int flags)
+{
+	return __filemap_sync(vma, address, size, flags);
+}
+#endif
+
 /*
  * MS_SYNC syncs the entire file - including mappings.
  *
Index: linux-2.6.8.1/mm/slab.c
===================================================================
--- linux-2.6.8.1.orig/mm/slab.c	2004-08-17 15:22:45.706185497 +1000
+++ linux-2.6.8.1/mm/slab.c	2004-08-17 15:24:37.832274921 +1000
@@ -2624,6 +2624,10 @@ static void enable_cpucache (kmem_cache_
 	if (limit > 32)
 		limit = 32;
 #endif
+#ifdef CONFIG_PREEMPT
+	if (limit > 16)
+		limit = 16;
+#endif
 	err = do_tune_cpucache(cachep, limit, (limit+1)/2, shared);
 	if (err)
 		printk(KERN_ERR "enable_cpucache failed for %s, error %d.\n",
Index: linux-2.6.8.1/mm/truncate.c
===================================================================
--- linux-2.6.8.1.orig/mm/truncate.c	2004-08-17 15:22:45.565208047 +1000
+++ linux-2.6.8.1/mm/truncate.c	2004-08-17 15:24:38.179219571 +1000
@@ -155,6 +155,7 @@ void truncate_inode_pages(struct address
 
 	next = start;
 	for ( ; ; ) {
+		cond_resched();
 		if (!pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) {
 			if (next == start)
 				break;