Re: [PATCH] mm: don't be stuck to rmap lock on reclaim path

[Andrew Morton]

On Wed, 4 May 2022 23:11:04 -0700 Minchan Kim <minchan@xxxxxxxxxx> wrote:

> > > +
> > > +	static struct rmap_walk_control rwc = {
> > >  		.rmap_one = page_idle_clear_pte_refs_one,
> > >  		.anon_lock = folio_lock_anon_vma_read,
> > >  	};
> 
> So, delta is

--- a/mm/page_idle.c~mm-dont-be-stuck-to-rmap-lock-on-reclaim-path-fix
+++ a/mm/page_idle.c
@@ -87,6 +87,10 @@ static void page_idle_clear_pte_refs(str
 {
 	struct folio *folio = page_folio(page);
 
+	/*
+	 * Since rwc.try_lock is unused, rwc is effectively immutable, so we
+	 * can make it static to save some cycles and stack.
+	 */
 	static struct rmap_walk_control rwc = {
 		.rmap_one = page_idle_clear_pte_refs_one,
 		.anon_lock = folio_lock_anon_vma_read,
_

and with that, I believe this change is good to be imported into mm-stable
later this week.