On 05/29/2012 08:07 PM, Glauber Costa wrote:

On 05/29/2012 06:52 PM, Christoph Lameter wrote:

quoted

On Fri, 25 May 2012, Glauber Costa wrote:

quoted

quoted

This patch charges allocation of a slab object to a particular
memcg.

Ok so a requirement is to support tracking of individual slab
objects to cgroups? That is going to be quite expensive since it will
touch the hotpaths.

No, we track pages. But all the objects in the page belong to the same
cgroup.

Also, please note the following:

The code that relays us to the right cache, is wrapped inside a static 
branch. Whoever is not using more than the root cgroup, will not suffer 
a single bit.

If you are, but your process is in the right cgroup, you will 
unfortunately pay function call penalty(*), but the code will make and 
effort to detect that as early as possible and resume.


(*) Not even then if you fall in the following categories, that are 
resolved inline:

+       if (!current->mm)
+               return cachep;
+       if (in_interrupt())
+               return cachep;
+       if (gfp & __GFP_NOFAIL)
+               return cachep;