Re: [PATCH v2] mm: page_alloc: dump migrate-failed pages

[David Hildenbrand]

On 10.03.21 08:42, Minchan Kim wrote:
> On Tue, Mar 09, 2021 at 08:15:41AM -0800, Minchan Kim wrote:
>
> < snip >
>
> > > [...]
> > > > +void dump_migrate_failure_pages(struct list_head *page_list)
> > > > +{
> > > > +	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor,
> > > > +			"migrate failure");
> > > > +	if (DYNAMIC_DEBUG_BRANCH(descriptor) &&
> > > > +			alloc_contig_ratelimit()) {
> > > > +		struct page *page;
> > > > +
> > > > +		WARN(1, "failed callstack");
> > > > +		list_for_each_entry(page, page_list, lru)
> > > > +			dump_page(page, "migration failure");
> > > > +	}
> > >
> > > Apart from the above, do we have to warn for something that is a
> > > debugging aid? A similar concern wrt dump_page which uses pr_warn and
> >
> > Make sense.
> >
> > > page owner is using even pr_alert.
> > > Would it make sense to add a loglevel parameter both into __dump_page
> > > and dump_page_owner?
> >
> > Let me try it.
>
> I looked though them and made first draft to clean them up.
>
> It's bigger than my initial expectaion because there are many callsites
> to use dump_page and stack_trace_print inconsistent loglevel.
> Since it's not a specific problem for this work, I'd like to deal with
> it as separate patchset since I don't want to be stuck on here for my
> initial goal.

Why the need to rush regarding your series?

If it will clean up your patch significantly, then I think doing the 
cleanups first is the proper way to go.

I really don't get why this is a real problem.


--
Thanks,

David / dhildenb