mm/damon/paddr: do page level access check for pageout DAMOS action on its own

'pageout' DAMOS action implementation of 'paddr' DAMON operations set asks
reclaim_pages() to do page level access check if the user is not asking
DAMOS to do that on its own.  Simplify the logic by making the check
always be done by 'paddr'.

Link: https://lkml.kernel.org/r/20240429224451.67081-3-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/damon/paddr.c b/mm/damon/paddr.c
index d5f2f7ddf863845a5f5b381663fae309bd1e99a8..974edef1740d0b12703fc5ec87e0fc5f2b452bbc 100644 (file)
--- a/mm/damon/paddr.c
+++ b/mm/damon/paddr.c
@@ -244,16 +244,22 @@ static unsigned long damon_pa_pageout(struct damon_region *r, struct damos *s)
 {
        unsigned long addr, applied;
        LIST_HEAD(folio_list);
-       bool ignore_references = false;
+       bool install_young_filter = true;
        struct damos_filter *filter;
 
-       /* respect user's page level reference check handling request */
+       /* check access in page level again by default */
        damos_for_each_filter(filter, s) {
                if (filter->type == DAMOS_FILTER_TYPE_YOUNG) {
-                       ignore_references = true;
+                       install_young_filter = false;
                        break;
                }
        }
+       if (install_young_filter) {
+               filter = damos_new_filter(DAMOS_FILTER_TYPE_YOUNG, true);
+               if (!filter)
+                       return 0;
+               damos_add_filter(s, filter);
+       }
 
        for (addr = r->ar.start; addr < r->ar.end; addr += PAGE_SIZE) {
                struct folio *folio = damon_get_folio(PHYS_PFN(addr));
@@ -275,7 +281,9 @@ static unsigned long damon_pa_pageout(struct damon_region *r, struct damos *s)
 put_folio:
                folio_put(folio);
        }
-       applied = reclaim_pages(&folio_list, ignore_references);
+       if (install_young_filter)
+               damos_destroy_filter(filter);
+       applied = reclaim_pages(&folio_list, true);
        cond_resched();
        return applied * PAGE_SIZE;
 }