Re: [RFC] mm: show message when updating min_free_kbytes in thp

Dave Hansen
2014-01-02T18:05:29Z

On 12/31/2013 04:29 PM, Han Pingtian wrote:
> min_free_kbytes may be updated during thp's initialization. Sometimes,
> this will change the value being set by user. Showing message will
> clarify this confusion.
...
> - if (recommended_min > min_free_kbytes)
> + if (recommended_min > min_free_kbytes) {
> min_free_kbytes = recommended_min;
> + pr_info("min_free_kbytes is updated to %d by enabling transparent hugepage.\n",
> + min_free_kbytes);
> + }

"updated" doesn't tell us much. It's also kinda nasty that if we enable
then disable THP, we end up with an elevated min_free_kbytes. Maybe we
should at least put something in that tells the user how to get back
where they were if they care:

"raising min_free_kbytes from %d to %d to help transparent hugepage
allocations"