diff -urN z/fs/buffer.c zz/fs/buffer.c
--- z/fs/buffer.c	Sun Dec  9 17:08:47 2001
+++ zz/fs/buffer.c	Sun Dec  9 17:09:18 2001
@@ -2539,7 +2539,7 @@
 	/* Uhhuh, start writeback so that we don't end up with all dirty pages */
 	write_unlock(&hash_table_lock);
 	spin_unlock(&lru_list_lock);
-	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 z/include/linux/sched.h zz/include/linux/sched.h
--- z/include/linux/sched.h	Sun Dec  9 17:08:48 2001
+++ zz/include/linux/sched.h	Sun Dec  9 17:10:23 2001
@@ -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 z/mm/slab.c zz/mm/slab.c
--- z/mm/slab.c	Sun Dec  9 17:08:47 2001
+++ zz/mm/slab.c	Sun Dec  9 17:09:18 2001
@@ -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))