On Thu 23-06-22 09:22:35, Yosry Ahmed wrote: > On Thu, Jun 23, 2022 at 2:43 AM Michal Hocko <mhocko@xxxxxxxx> wrote: > > > > On Thu 23-06-22 01:35:59, Yosry Ahmed wrote: [...] > > > In our internal version of memory.reclaim that we recently upstreamed, > > > we do not account vmpressure during proactive reclaim (similar to how > > > psi is handled upstream). We want to make sure this behavior also > > > exists in the upstream version so that consolidating them does not > > > break our users who rely on vmpressure and will start seeing increased > > > pressure due to proactive reclaim. > > > > These are good reasons to have this patch in your tree. But why is this > > patch benefitial for the upstream kernel? It clearly adds some code and > > some special casing which will add a maintenance overhead. > > It is not just Google, any existing vmpressure users will start seeing > false pressure notifications with memory.reclaim. The main goal of the > patch is to make sure memory.reclaim does not break pre-existing users > of vmpressure, and doing it in a way that is consistent with psi makes > sense. memory.reclaim is v2 only feature which doesn't have vmpressure interface. So I do not see how pre-existing users of the upstream kernel can see any breakage. -- Michal Hocko SUSE Labs
