Thanks Michal. On 11/15/2023 7:39 PM, Michal Hocko wrote: >> Also If you have any comments on [PATCH V2 2/3] mm: page_alloc: correct >> high atomic reserve calculations will help me. > I do not have a strong opinion on that one to be honest. I am not even > sure that reserving a full page block (4MB) on small systems as > presented is really a good use of memory. May be other way to look at that patch is comment is really not being reflected in the code. It says, " Limit the number reserved to 1 pageblock or roughly 1% of a zone.", but the current code is making it 2 pageblocks. So, for 4M block size, it is > 1%. A second patch, that I will post, like not reserving the high atomic page blocks on small systems -- But how to define the meaning of small systems is not sure. Instead will let the system administrators chose this through either: a) command line param, high_atomic_reserves=off, on by default -- Another knob, so admins may really not like this? b) CONFIG_HIGH_ATOMIC_RESERVES, which if not defined, will not reserve. Please lmk If you have any more suggestions here? Also, I am thinking to request Andrew to pick [PATCH V2 1/3] patch and take these discussions separately in a separate thread. Thanks, Charan
