On Tue, Aug 19, 2025 at 06:25:36PM -0700, Shakeel Butt wrote: > On Wed, Aug 20, 2025 at 12:46:43AM +0100, Matthew Wilcox wrote: > > OK, but couldn't we make that argument for anything else? Like slab, > > say. Why's "file" memory different? > > Good point and I think it does apply to other memory types too. I would > call "file" memory to be more important as it is one of the largest > consumer of DRAM on, at least, Meta infra. Slab needs a bit more thought. > At the system level (i.e. /proc/meminfo), we account at the page (or > slab) level while for memcg, we account per-object (plus obj_cgroup > pointer). That was supposed to be a reductio ad absurdum, not an invitation to add more counters. Look, if this is information you really need, I think you should come up with a better way of collecting it than by adding new counters and new complexity to everything involved in GFP_ACCOUNT activities. The unaccounted address_spaces are a very tiny percentage of file memory, at least as far as this patch set goes. I don't think this patch is justifiable on its face.
