On Fri, 24 Nov 2023, Charan Teja Kalla wrote: > Highatomic reserves are set to roughly 1% of zone for maximum and a > pageblock size for minimum. Encountered a system with the below > configuration: > Normal free:7728kB boost:0kB min:804kB low:1004kB high:1204kB > reserved_highatomic:8192KB managed:49224kB > > On such systems, even a single pageblock makes highatomic reserves are > set to ~8% of the zone memory. This high value can easily exert pressure > on the zone. > > Per discussion with Michal and Mel, it is not much useful to reserve > the memory for highatomic allocations on such small systems[1]. Since > the minimum size for high atomic reserves is always going to be a > pageblock size and if 1% of zone managed pages is going to be below > pageblock size, don't reserve memory for high atomic allocations. Thanks > Michal for this suggestion[2]. > > Since no memory is being reserved for high atomic allocations and if > respective allocation failures are seen, this patch can be reverted. > > [1] https://lore.kernel.org/linux-mm/20231117161956.d3yjdxhhm4rhl7h2@xxxxxxxxxxxxxxxxxxx/ > [2] https://lore.kernel.org/linux-mm/ZVYRJMUitykepLRy@tiehlicka/ > > Signed-off-by: Charan Teja Kalla <quic_charante@xxxxxxxxxxx> Acked-by: David Rientjes <rientjes@xxxxxxxxxx>
