On 07/30/2012 04:50 PM, Kirill A. Shutemov wrote:

On Wed, Jul 25, 2012 at 06:38:15PM +0400, Glauber Costa wrote:

quoted

This patch creates a mechanism that skip memcg allocations during
certain pieces of our core code. It basically works in the same way
as preempt_disable()/preempt_enable(): By marking a region under
which all allocations will be accounted to the root memcg.

We need this to prevent races in early cache creation, when we
allocate data using caches that are not necessarily created already.

Why not a GFP_* flag?

The main reason for this is to prevent nested calls of
kmem_cache_create(), since they could create (and in my tests, do
create) funny circular dependencies with each other. So the cache
creation itself would proceed without involving memcg.

At first, it is a bit weird to have cache creation itself depending on a
allocation flag test.

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>