Re: [PATCH] mm: respect the __GFP_NOWARN flag when warning about stalls

From: Shakeel Butt
Date: Wed Sep 13 2017 - 10:52:10 EST

> We would have to consider (instead of jiffies) the time the process was
> either running, or waiting on something that's related to memory
> allocation/reclaim (page lock etc.). I.e. deduct the time the process
> was runable but there was no available cpu. I expect however that such
> level of detail wouldn't be feasible here, though?

Johannes' memdelay work (once merged) might be useful here. I think
memdalay can differentiate between an allocating process getting
delayed due to preemption or due to unsuccessful reclaim/compaction.
If the delay is due to unsuccessful reclaim/compaction then we should
warn here.