On Thu, Aug 07, 2014 at 03:40:46PM -0700, Andrew Morton wrote: > On Thu, 7 Aug 2014 12:25:07 -0400 Johannes Weiner <hannes@xxxxxxxxxxx> wrote: > > > mem_cgroup_migrate() is suitable for replace_page_cache() as well, > > which gets rid of mem_cgroup_replace_page_cache(). > > > > Could you please update it to say: > > > > mem_cgroup_migrate() is suitable for replace_page_cache() as well, > > which gets rid of mem_cgroup_replace_page_cache(). However, care > > needs to be taken because both the source and the target page can > > already be charged and on the LRU when fuse is splicing: grab the page > > lock on the charge moving side to prevent changing pc->mem_cgroup of a > > page under migration. Also, the lruvecs of both pages change as we > > uncharge the old and charge the new during migration, and putback may > > race with us, so grab the lru lock and isolate the pages iff on LRU to > > prevent races and ensure the pages are on the right lruvec afterward. > > OK thanks, I did that, separated out > mm-memcontrol-rewrite-uncharge-api-fix-page-cache-migration.patch again > and copied the [0/n] changelog text into mm-memcontrol-rewrite-charge-api.patch. > > I'll get these (presently at http://ozlabs.org/~akpm/mmots/broken-out/) > > mm-memcontrol-rewrite-charge-api.patch > mm-memcontrol-rewrite-uncharge-api.patch > mm-memcontrol-rewrite-uncharge-api-fix-page-cache-migration.patch > mm-memcontrol-use-page-lists-for-uncharge-batching.patch > # > page-cgroup-trivial-cleanup.patch > page-cgroup-get-rid-of-nr_pcg_flags.patch > # > # > memcg-remove-lookup_cgroup_page-prototype.patch mm-memcontrol-avoid-charge-statistics-churn-during-page-migration.patch came a bit later, but it's a small optimization directly relevant to the above changes, so you may want to send it along with them. Michal already acked it on the list: http://marc.info/?l=linux-mm&m=140724569618836&w=2 -- 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>