On 08/15/2012 07:34 PM, Christoph Lameter wrote: > On Wed, 15 Aug 2012, Glauber Costa wrote: > >> On 08/15/2012 06:47 PM, Christoph Lameter wrote: >>> On Wed, 15 Aug 2012, Michal Hocko wrote: >>> >>>>> That is not what the kernel does, in general. We assume that if he wants >>>>> that memory and we can serve it, we should. Also, not all kernel memory >>>>> is unreclaimable. We can shrink the slabs, for instance. Ying Han >>>>> claims she has patches for that already... >>>> >>>> Are those patches somewhere around? >>> >>> You can already shrink the reclaimable slabs (dentries / inodes) via >>> calls to the subsystem specific shrinkers. Did Ying Han do anything to >>> go beyond that? >>> >> That is not enough for us. >> We would like to make sure that the objects being discarded belong to >> the memcg which is under pressure. We don't need to be perfect here, and >> an occasional slip is totally fine. But if in general, shrinking from >> memcg A will mostly wipe out objects from memcg B, we harmed the system >> in return for nothing good. > > How can you figure out which objects belong to which memcg? The ownerships > of dentries and inodes is a dubious concept already. > Remember we copy over the metadata and create copies of the caches per-memcg. Therefore, a dentry belongs to a memcg if it was allocated from the slab pertaining to that memcg. It is not 100 % accurate, but it is good enough. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>