On Wed, Jan 24, 2024 at 02:33:29AM +0800, Kemeng Shi wrote: > The wb_calc_thresh will calculate wb's share in global wb domain. We need > to wb's share in mem_cgroup_wb_domain for mdtc. Call __wb_calc_thresh > instead of wb_calc_thresh to fix this. That function is calculating the wb's portion of wb portion in the whole system so that threshold can be distributed accordingly. So, it has to be compared in the global domain. If you look at the comment on top of struct wb_domain, it says: /* * A wb_domain represents a domain that wb's (bdi_writeback's) belong to * and are measured against each other in. There always is one global * domain, global_wb_domain, that every wb in the system is a member of. * This allows measuring the relative bandwidth of each wb to distribute * dirtyable memory accordingly. */ Also, how is this tested? Was there a case where the existing code misbehaved that's improved by this patch? Or is this just from reading code? Thanks. -- tejun
