On Wed, 5 Feb 2025 11:05:29 -0500 Johannes Weiner <hannes@xxxxxxxxxxx> wrote: > On Wed, Feb 05, 2025 at 11:54:05AM +0530, Bharata B Rao wrote: > > On 31-Jan-25 6:39 PM, Jonathan Cameron wrote: > > > On Fri, 31 Jan 2025 12:28:03 +0000 > > > Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> wrote: [...] > > Here is a compilation of available temperature sources and how the > > hot/access data is consumed by different subsystems: > > This is super useful, thanks for collecting this. Indeed. Thank you Bharata! [...] > For the following table, it might be useful to add *when* the source > produces this information. Sampling frequency is a likely challenge: > consumers have different requirements, and overhead should be limited > to the minimum required to serve enabled consumers. +1 > > Here is an (incomplete) attempt - sorry about the long lines: > > > And here is an attempt to compile how different subsystems > > use the above data: > > ============================================================== > > Source Subsystem Consumption Activation/Frequency [...] > > ============================================================== > > PTE A bit via DAMON LRU activation, Continuous sampling (configurable)? > > rmap walk hot page promotion, (I believe SJ is looking into > > demotion etc auto-tuning this). You're right. I'm working on auto-tuning of the sampling/aggregation intervals of DAMON based on its tuning guide theory[1]. Hopefully I will be able to post an RFC patch series within a couple of weeks. > > ============================================================== > > Platform hints NUMAB NUMAB=1 Locality based > > (AMD IBS) balancing and > > NUMAB=2 hot page > > promotion > > ============================================================== > > Device hints NUMAB NUMAB=2 hot page > > promotion > > ============================================================== > > The last two are listed as possibilities. I'm also trying to extend DAMON to use PROT_NONE faults and AMD IBS like access check sources. Hopefully I will share more details of the plan and experiment results for the PROT_NONE faults extension by LSFMMBPF. [1] https://lore.kernel.org/20241202175459.2005526-1-sj@xxxxxxxxxx Thanks, SJ [...]
