[PATCH 03/03] Cpuset: might_sleep_if check in cpuset_zones_allowed

[Paul Jackson <pj@sgi.com>]

From: Paul Jackson <pj@sgi.com>

It's too easy to incorrectly call cpuset_zone_allowed() in an
atomic context without __GFP_HARDWALL set, and when done, it is
not noticed until a tight memory situation forces allocations
to be tried outside the current cpuset.

Add a 'might_sleep_if()' check, to catch this earlier on, instead
of waiting for a similar check in the mutex_lock() code, which
is only rarely invoked.

Signed-off-by: Paul Jackson <pj@sgi.com>

---

 kernel/cpuset.c |    1 +
 1 file changed, 1 insertion(+)

--- 2.6.17-rc4-mm1.orig/kernel/cpuset.c	2006-05-17 20:31:22.577065566 -0700
+++ 2.6.17-rc4-mm1/kernel/cpuset.c	2006-05-17 20:31:36.261218192 -0700
@@ -2261,6 +2261,7 @@ int __cpuset_zone_allowed(struct zone *z
 	if (in_interrupt())
 		return 1;
 	node = z->zone_pgdat->node_id;
+	might_sleep_if(!(gfp_mask & __GFP_HARDWALL));
 	if (node_isset(node, current->mems_allowed))
 		return 1;
 	if (gfp_mask & __GFP_HARDWALL)	/* If hardwall request, stop here */

-- 
                          I won't rest till it's the best ...
                          Programmer, Linux Scalability
                          Paul Jackson <pj@sgi.com> 1.650.933.1373