Re: [PATCH] mm: fix long time stall from mm_populate

[Andrew Morton]

On Wed, 12 Feb 2020 11:53:22 -0800 Minchan Kim <minchan@xxxxxxxxxx> wrote:

> > That's definitely wrong.  It'll clear PageReclaim and then pretend it did
> > nothing wrong.
> > 
> > 	return !PageWriteback(page) ||
> > 		test_and_clear_bit(PG_reclaim, &page->flags);
> > 
> 
> Much better, Thanks for the review, Matthew!
> If there is no objection, I will send two patches to Andrew.
> One is PageReadahead strict, the other is limit retry from mm_populate.

With much more detailed changelogs, please!

This all seems rather screwy.  if a page is under writeback then it is
uptodate and we should be able to fault it in immediately.