On Tue, Apr 13, 2021 at 09:20:23PM -0400, Waiman Long wrote: > The caller of mod_memcg_lruvec_state() has both memcg and lruvec readily > available. So both of them are now passed to mod_memcg_lruvec_state() > and __mod_memcg_lruvec_state(). The __mod_memcg_lruvec_state() is > updated to allow either of the two parameters to be set to null. This > makes mod_memcg_lruvec_state() equivalent to mod_memcg_state() if lruvec > is null. > > The new __mod_memcg_lruvec_state() function will be used in the next > patch as a replacement of mod_memcg_state() in mm/percpu.c for the > consolidation of the memory uncharge and vmstat update functions in > the kmem_cache_free() path. This requires users who want both to pass a pgdat that can be derived from the lruvec. This is error prone, and we just acked a patch that removes this very thing from mem_cgroup_page_lruvec(). With the suggestion for patch 2, this shouldn't be necessary anymore, though. And sort of underlines my point around that combined function creating akwward code above and below it.
