Re: [patch] mm, oom: stop reclaiming if GFP_ATOMIC will start failing soon

[Tetsuo Handa]

On 2020/04/27 12:12, David Rientjes wrote:
> Tetsuo: the specific allocation that triggers a page allocation failure is 
> not interesting; we have tens of thousands of examples.  Each example is 
> simply the unlucky last GFP_ATOMIC allocation that fails; the interesting 
> point is the amount of free memory.  In other words, when free memory is 
> below ALLOC_HIGH watermarks, we assume that we have depleted memory 
> reserves *faster* than when user allocations started to fail.  In the 
> interest of userspace being responsive, we should oom kill here.

My interest is, which function (and which process if process context) is [ab]using
GFP_ATOMIC (or __GFP_MEMALLOC) allocations enough to hit memory allocation failure.
GFP_NOWAIT (or __GFP_NOMEMALLOC) could be used if that allocation can't sleep and
can't shortly recover free memory.