On Wed, 17 Jan 2024 13:11:03 -0800 SeongJae Park <sj@xxxxxxxxxx> wrote: [...] > Hi Honggyu, > > On Wed, 17 Jan 2024 20:49:25 +0900 Honggyu Kim <honggyu.kim@xxxxxx> wrote: > > > Hi SeongJae, > > > > Thanks very much for your comments in details. > > > > On Tue, 16 Jan 2024 12:31:59 -0800 SeongJae Park <sj@xxxxxxxxxx> wrote: > > [...] > > > To this end, I feel the problem might be able te be simpler, because this > > > patchset is trying to provide two sophisticated operations, while I think a > > > simpler approach might be possible. My humble simpler idea is adding a DAMOS > > > operation for moving pages to a given node (like sys_move_phy_pages RFC[1]), > > > instead of the promote/demote. Because the general pages migration can handle > > > multiple cases including the promote/demote in my humble assumption. [...] > > > In more detail, users could decide which is the appropriate node for promotion > > > or demotion and use the new DAMOS action to do promotion and demotion. Users > > > would requested to decide which node is the proper promotion/demotion target > > > nodes, but that decision wouldn't be that hard in my opinion. > > > > > > For this, 'struct damos' would need to be updated for such argument-dependent > > > actions, like 'struct damos_filter' is haing a union. > > > > That might be a better solution. I will think about it. > > More specifically, I think receiving an address range as the argument might > more flexible than just NUMA node. Maybe we can imagine proactively migrating > cold movable pages from normal zones to movable zones, to avoid normal zone > memory pressure. Yet another crazy idea. Finding hot regions in the middle of cold region and move to besides of other hot pages. As a result, memory is sorted by access temperature even in same node, and the system gains more spatial locality, which benefits general locality-based algorithms including DAMON's adaptive regions adjustment. Thanks, SJ [...]
