On Wed, Apr 5, 2023 at 1:00 AM Michal Koutný <mkoutny@xxxxxxxx> wrote: > > On Tue, Apr 04, 2023 at 11:09:02AM -0700, Yosry Ahmed <yosryahmed@xxxxxxxxxx> wrote: > > IIUC there are multiple places where we can sleep in this path, we can > > sleep waiting for a page to be read from disk, we can sleep during > > allocating the page to read into, and IIUC the allocations on the > > fault path can even run into reclaim, going into the vmscan code. So > > there are precedents, but I am not sure if that's enough argument. > > I expect it'd depend on the proportion of the slow/fast paths. > OK, let's see how it turns out in wider population. Agreed. It also depends on the number of memcgs and how much the periodic flusher is keeping up. I think no amount of testing will cover all or even most workloads. > > Thanks, > Michal