diff -urN atomic-alloc-ref/fs/buffer.c atomic-alloc/fs/buffer.c
--- atomic-alloc-ref/fs/buffer.c	Wed Jan  2 02:30:43 2002
+++ atomic-alloc/fs/buffer.c	Wed Jan  2 02:31:21 2002
@@ -2548,7 +2548,7 @@
 	write_unlock(&hash_table_lock);
 	spin_unlock(&lru_list_lock);
 	gfp_mask = pf_gfp_mask(gfp_mask);
-	if (gfp_mask & __GFP_IO) {
+	if (gfp_mask & __GFP_IO && !(current->flags & PF_ATOMICALLOC)) {
 		if ((gfp_mask & __GFP_HIGHIO) || !PageHighMem(page)) {
 			if (sync_page_buffers(bh)) {
 				/* no IO or waiting next time */
diff -urN atomic-alloc-ref/include/linux/sched.h atomic-alloc/include/linux/sched.h
--- atomic-alloc-ref/include/linux/sched.h	Wed Jan  2 02:30:43 2002
+++ atomic-alloc/include/linux/sched.h	Wed Jan  2 02:31:42 2002
@@ -427,19 +427,16 @@
 /*
  * Per process flags
  */
-#define PF_ALIGNWARN	0x00000001	/* Print alignment warning msgs */
-					/* Not implemented yet, only for 486*/
-#define PF_STARTING	0x00000002	/* being created */
-#define PF_EXITING	0x00000004	/* getting shut down */
-#define PF_FORKNOEXEC	0x00000040	/* forked but didn't exec */
-#define PF_SUPERPRIV	0x00000100	/* used super-user privileges */
-#define PF_DUMPCORE	0x00000200	/* dumped core */
-#define PF_SIGNALED	0x00000400	/* killed by a signal */
-#define PF_MEMALLOC	0x00000800	/* Allocating memory */
-#define PF_FREE_PAGES	0x00002000	/* per process page freeing */
-#define PF_NOIO		0x00004000	/* avoid generating further I/O */
-
-#define PF_USEDFPU	0x00100000	/* task used FPU this quantum (SMP) */
+#define PF_EXITING	(1UL<<0)	/* getting shut down */
+#define PF_FORKNOEXEC	(1UL<<1)	/* forked but didn't exec */
+#define PF_SUPERPRIV	(1UL<<2)	/* used super-user privileges */
+#define PF_DUMPCORE	(1UL<<3)	/* dumped core */
+#define PF_SIGNALED	(1UL<<4)	/* killed by a signal */
+#define PF_MEMALLOC	(1UL<<5)	/* Allocating memory */
+#define PF_USEDFPU	(1UL<<6)	/* task used FPU this quantum (SMP) */
+#define PF_ATOMICALLOC	(1UL<<7)	/* do not block during memalloc */
+#define PF_FREE_PAGES	(1UL<<8)	/* per process page freeing */
+#define PF_NOIO		(1UL<<9)	/* avoid generating further I/O */
 
 /*
  * Ptrace flags
diff -urN atomic-alloc-ref/mm/slab.c atomic-alloc/mm/slab.c
--- atomic-alloc-ref/mm/slab.c	Wed Jan  2 02:30:43 2002
+++ atomic-alloc/mm/slab.c	Wed Jan  2 02:31:21 2002
@@ -1715,7 +1715,7 @@
 	unsigned int scan;
 	int ret = 0;
 
-	if (gfp_mask & __GFP_WAIT)
+	if (gfp_mask & __GFP_WAIT && !(current->flags & PF_ATOMICALLOC))
 		down(&cache_chain_sem);
 	else
 		if (down_trylock(&cache_chain_sem))