On Mon, Nov 30, 2020 at 01:01:18PM -0800, Shakeel Butt wrote: > On Mon, Nov 30, 2020 at 12:34 PM Roman Gushchin <guro@xxxxxx> wrote: > > > > On Wed, Nov 25, 2020 at 04:56:01PM -0800, Shakeel Butt wrote: > > > Many workloads consumes significant amount of memory in pagetables. This > > > patch series exposes the pagetable comsumption for each memory cgroup. > > > > Hi Shakeel! > > > > The code looks good to me. However I'm not sure I understand what's the > > use case for the new statistics? Can you, please, elaborate a bit more here? > > > > From a very first glance, the size of pagetables should be _roughly_ equal > > to the size_of(pte)/PAGE_SIZE*(size of a cgroup) and should not exceed 1% > > of the cgroup size. So for all but very large cgroups the value will be > > in the noise of per-cpu counters. Perhaps I'm missing some important cases? > > > > I think this is in general a good metric to have but one specific > use-case we have is the user space network driver which mmaps the > memory of the applications for zero copy data transfers. This driver > can consume a large amount of memory in page tables. So, this metric > becomes really useful here. Got it, thank you for the explanation! Would you mind to add this text to the cover letter as an example? Acked-by: Roman Gushchin <guro@xxxxxx> for the series. Thanks!
