On Fri, 21 Jun 2024 04:48:30 +0000 "Ho-Ren (Jack) Chuang" <horen.chuang@xxxxxxxxx> wrote: > If we simply move the set_node_memory_tier() from memory_tier_init() to > late_initcall(), it will result in HMAT not registering the > mt_adistance_algorithm callback function, Immediate reaction: then don't do that! > because set_node_memory_tier() > is not performed during the memory tiering initialization phase, > leading to a lack of correct default_dram information. > > Therefore, we introduced a nodemask to pass the information of the > default DRAM nodes. The reason for not choosing to reuse > default_dram_type->nodes is that it is not clean enough. So in the end, > we use a __initdata variable, which is a variable that is released once > initialization is complete, including both CPU and memory nodes for HMAT > to iterate through. > > Besides, since default_dram_type may be checked/used during the > initialization process of HMAT and drivers, it is better to keep the > allocation of default_dram_type in memory_tier_init(). What is this patch actually aiming to do? Is it merely a code cleanup, or are there functional changes? > Signed-off-by: Ho-Ren (Jack) Chuang <horenchuang@xxxxxxxxxxxxx> > --- > Hi all, > > The current memory tier initialization process is distributed across two > different functions, memory_tier_init() and memory_tier_late_init(). This > design is hard to maintain. Thus, this patch is proposed to reduce the > possible code paths by consolidating different initialization patches into one. Ah, there it is. Please make this the opening paragraph, not an aside buried below the ^---$. I'll await review input before proceeding with this, thanks.