On Wed 10-02-21 12:07:57, zhou xianrong wrote: > > On 2021/2/9 下午5:23, Michal Hocko wrote: > > On Tue 09-02-21 16:23:13, zhou wrote: > > > From: zhou xianrong <xianrong.zhou@xxxxxxxxxxxxx> > > > > > > For purpose of better migration cma pages are allocated after > > > failure movalbe allocations and are used normally for file pages > > > or anonymous pages. > > > > > > In reclaim path so many cma pages if configurated are reclaimed > > > from lru lists in kswapd mainly or direct reclaim triggered by > > > unmovable or reclaimable allocations. But these cma pages can not > > > be used by original unmovable or reclaimable allocations. So the > > > reclaim are unnecessary. > > > > > > In a same system if the cma pages were configurated to large then > > > more failture unmovable (vmalloc etc.) or reclaimable (slab etc.) > > > allocations are arised and then more kswapd rounds are triggered > > > and then more cma pages are reclaimed. > > Could you be more specific? Do you have any numbers and an example > > configuration when this is visible? > It should be implicit. Right but the scale of the problem is an important part of _any_ patch justification. -- Michal Hocko SUSE Labs
