June 21, 2024 at 6:34 PM, "Andrew Morton" <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: Hi Andrew, Thanks for the feedback. I will send a v2 with the patch description written in a cover letter. > > 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. >
