On Tue, 9 Jul 2024 20:31:15 +0800 Zhiguo Jiang <justinjiang@xxxxxxxx> wrote: > The releasing process of the non-shared anonymous folio mapped solely by > an exiting process may go through two flows: 1) the anonymous folio is > firstly is swaped-out into swapspace and transformed into a swp_entry > in shrink_folio_list; 2) then the swp_entry is released in the process > exiting flow. This will result in the high cpu load of releasing a > non-shared anonymous folio mapped solely by an exiting process. > > When the low system memory and the exiting process exist at the same > time, it will be likely to happen, because the non-shared anonymous > folio mapped solely by an exiting process may be reclaimed by > shrink_folio_list. > > This patch is that shrink skips the non-shared anonymous folio solely > mapped by an exting process and this folio is only released directly in > the process exiting flow, which will save swap-out time and alleviate > the load of the process exiting. It would be helpful to provide some before-and-after runtime measurements, please. It's a performance optimization so please let's see what effect it has.
