On Tue, 28 Jan 2020 05:20:35 -0500 Qian Cai <cai@xxxxxx> wrote: > > > > On Jan 28, 2020, at 3:58 AM, sjpark@xxxxxxxxxx wrote: > > > > This patchset introduces a new kernel module for practical monitoring of data > > accesses, namely DAMON. > > > > The patches are organized in the following sequence. The first four patches > > implements the core logic of DAMON one by one. After that, the fifth patch > > implements DAMON's debugfs interface for users. To provide a minimal reference > > to the low level interface and for more convenient use/tests of the DAMON, the > > sixth patch implements an user space tool. The seventh patch adds a document > > for administrators of DAMON, and the eightth patch provides DAMON's kunit > > tests. Finally, the ninth patch implements a tracepoint for DAMON. As the > > tracepoint prints every monitoring results, it will be easily integrated with > > other tracers supporting tracepoints including perf. > > I am a bit surprised that this patchset did not include perf maintainers which makes me wonder if there is any attempt to discuss first if we actually need a whole new subsystem for it or a existing tool can be enhanced. For the comments from perf maintainers, I added Steven Rostedt and Arnaldo Carvalho de Melo first, but I might missed someone. If you recommend some more people, I will add them to recipients. I made DAMON as a new subsystem because I think no existing subsystem fits well to be a base of DAMON, due to DAMON's unique goals and mechanisms described below in the original cover letter. The existing subsystem that most similar to DAMON might be 'mm/page_idle.c'. However, there are many conceptual differences with DAMON. One biggest difference I think is the target. 'page_idle' deals with physical page frames while DAMON deals with virtual address of specific processes. Nevertheless, if you have some different opinion, please let me know. Thanks, SeongJae Park