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