Write-Only

Below is also sent as a mail to DAMON mailing list and relevant people. I’m working [1] on extending DAMON to monitor accesses that are made by specific CPUs, and/or for writes. The aimed usages include NUMA hit/miss monitoring [2], Kernel Same page Merging scan target selection [3,4], cache aware CPU scheduling, live migration target VM selection [5], and general NUMA-aware pages migration [6]. I posted its first working version as RFC v2 [7] about four months ago....

From the very early days of DAMON, there were attempts to extend it for cpus-aware monitoring and write-only monitoring. In 2022, Xin Hao proposed extending DAMON for NUMA access statistics. In 2022 and 2025, Pedro Demarchi Gomes proposed extending DAMON for writes-only monitoring. Those proposals are not yet upstreamed though. We continued similar DAMON extension discussions publicly and privately, with multiple parties, though. I was recently taking some time on these, and happy to announce the first working prototype for the extensions....