Re: [PATCH 09/11] mm/page_alloc: Avoid conflating IRQs disabled with zone->lock

[Mel Gorman]

On Thu, Apr 15, 2021 at 02:25:36PM +0200, Vlastimil Babka wrote:
> > @@ -3294,6 +3295,7 @@ void free_unref_page_list(struct list_head *list)
> >     struct page *page, *next;
> >     unsigned long flags, pfn;
> >     int batch_count = 0;
> > +   int migratetype;
> >  
> >     /* Prepare pages for freeing */
> >     list_for_each_entry_safe(page, next, list, lru) {
> > @@ -3301,15 +3303,28 @@ void free_unref_page_list(struct list_head *list)
> >             if (!free_unref_page_prepare(page, pfn))
> >                     list_del(&page->lru);
> >             set_page_private(page, pfn);
> 
> Should probably move this below so we don't set private for pages that then go
> through free_one_page()? Doesn't seem to be a bug, just unneccessary.
> 

Sure.

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 1d87ca364680..a9c1282d9c7b 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3293,7 +3293,6 @@ void free_unref_page_list(struct list_head *list)
                pfn = page_to_pfn(page);
                if (!free_unref_page_prepare(page, pfn))
                        list_del(&page->lru);
-               set_page_private(page, pfn);
 
                /*
                 * Free isolated pages directly to the allocator, see
@@ -3307,6 +3306,8 @@ void free_unref_page_list(struct list_head *list)
                                list_del(&page->lru);
                        }
                }
+
+               set_page_private(page, pfn);
        }
 
        local_lock_irqsave(&pagesets.lock, flags);

-- 
Mel Gorman
SUSE Labs