On 25/01/2021 09:56, Jan Beulich wrote: > On 24.01.2021 05:47, Elliott Mitchell wrote: >> Previously p2m_pod_set_cache_target() would fall back to allocating 4KB >> pages if 2MB pages ran out. This is counterproductive since it suggests >> severe memory pressure and is likely a precursor to a memory exhaustion >> panic. As such don't try to fill requests for 2MB pages from 4KB pages >> if 2MB pages run out. > I disagree - there may be ample 4k pages available, yet no 2Mb > ones at all. I only agree that this _may_ be counterproductive > _if indeed_ the system is short on memory.
Further to this, PoD is very frequently used in combination with ballooning operations, in which case there are (or can be made to be) plenty of 4k pages, even without a single 2M range in sight. ~Andrew
