Re: [PATCH] mm, oom: protect !costly allocations some more

[Sergey Senozhatsky]

On (03/08/16 10:24), Vlastimil Babka wrote:
[..]
> > @@ -3294,6 +3289,18 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
> >  				 did_some_progress > 0, no_progress_loops))
> >  		goto retry;
> >  
> > +	/*
> > +	 * !costly allocations are really important and we have to make sure
> > +	 * the compaction wasn't deferred or didn't bail out early due to locks
> > +	 * contention before we go OOM.
> > +	 */
> > +	if (order && order <= PAGE_ALLOC_COSTLY_ORDER) {
> > +		if (compact_result <= COMPACT_CONTINUE)
> 
> Same here.
> I was going to say that this didn't have effect on Sergey's test, but
> turns out it did :)

I'm sorry, my test is not correct. I have disabled compaction last weeked on
purpose - to provoke more OOM-kills and OOM conditions for reworked printk()
patch set testing (http://marc.info/?l=linux-kernel&m=145734549308803); and I
forgot to re-enable it.

	-ss