Re: excessive CPU utilization by isolate_freepages?

[David Rientjes]

On Thu, 28 Jun 2012, Minchan Kim wrote:

> >>> > > https://lkml.org/lkml/2012/6/21/30
> >> > 
> > Not sure if Jim is using memcg; if not, then this won't be helpful.
> > 
> 
> 
> It doesn't related to memcg.
> if compaction_alloc can't find suitable migration target, it returns NULL.
> Then, migrate_pages should be exit.
> 

If isolate_freepages() is going to fail, then this zone should have been 
skipped when checking for compaction_suitable().  In Jim's perf output, 
compaction_suitable() returns COMPACT_CONTINUE for a transparent hugepage.  
Why is zone_watermark_ok(zone, 0 low_wmark + 1024, 0, 0) succeeding if 
isolate_freepages() is going to fail?
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/