Re: [PATCH] thp: do not adjust zone water marks if khugepaged is not started

["Kirill A. Shutemov" <kirill@shutemov.name>]

On Fri, Mar 27, 2015 at 03:00:26PM -0700, Andrew Morton wrote:
> On Fri, 27 Mar 2015 14:47:08 -0700 Andrew Morton <akpm@linux-foundation.org> wrote:
> 
> > Fair enough, but take a look at start_khugepaged():
> > 
> > : static int start_khugepaged(void)
> > : {
> > : 	int err = 0;
> > : 	if (khugepaged_enabled()) {
> > : 		if (!khugepaged_thread)
> > : 			khugepaged_thread = kthread_run(khugepaged, NULL,
> > : 							"khugepaged");
> > : 		if (unlikely(IS_ERR(khugepaged_thread))) {
> > : 			pr_err("khugepaged: kthread_run(khugepaged) failed\n");
> > : 			err = PTR_ERR(khugepaged_thread);
> > : 			khugepaged_thread = NULL;
> > 
> > -->> stop here 
> > 
> > : 		}
> > : 
> > : 		if (!list_empty(&khugepaged_scan.mm_head))
> > : 			wake_up_interruptible(&khugepaged_wait);
> > : 
> > : 		set_recommended_min_free_kbytes();
> > : 	} else if (khugepaged_thread) {
> > : 		kthread_stop(khugepaged_thread);
> > : 		khugepaged_thread = NULL;
> > : 	}
> > : 
> > : 	return err;
> > : }
> 
> Looking more closely...  This code seems a bit screwy.
> 
> - why is set_recommended_min_free_kbytes() a late_initcall?  We've
>   already done that within
>   subsys_initcall->hugepage_init->set_recommended_min_free_kbytes()
> 
> - there isn't much point in running start_khugepaged() if we've just
>   set transparent_hugepage_flags to zero.
> 
> - start_khugepaged() is misnamed.
> 
> So something like this?

Looks like you didn't apply this. Here's proper patch: