On Mon, May 2, 2022 at 8:20 AM Dave Hansen <dave.hansen@xxxxxxxxx> wrote: > > > The current memory tiering interface needs to be improved to address > > several important use cases: > > FWIW, I totally agree. We knew when that code went in that the default > ordering was feeble. There were patches to export the demotion order > and allow it to be modified from userspace, but they were jettisoned at > some point. > > > Memory tiering hierarchy is rebuilt upon hot-add or hot-remove of a > > memory node, but is NOT rebuilt upon hot-add or hot-remove of a CPU > > node. > > Yeah, this would be a welcome improvement if we can get there. > > > * /sys/devices/system/node/memory_tiers > > > > Format: node list (one tier per line, in the tier order) > > > > When read, list memory nodes by tiers. > > Nit: this would seems to violate the one-value-per-file sysfs guideline. > It can be fixed by making tiers actual objects, which would have some > other nice benefits too. > Good point. One tier per file should work as well. It can be even better to have a separate tier sub-tree.
