Commit a3235ea2 authored by Kalesh Singh's avatar Kalesh Singh Committed by Andrew Morton
Browse files

Multi-gen LRU: fix can_swap in lru_gen_look_around() 

walk->can_swap might be invalid since it's not guaranteed to be
initialized for the particular lruvec.  Instead deduce it from the folio
type (anon/file).

Link: https://lkml.kernel.org/r/20230802025606.346758-3-kaleshsingh@google.com


Fixes: 018ee47f ("mm: multi-gen LRU: exploit locality in rmap")
Signed-off-by: default avatarKalesh Singh <kaleshsingh@google.com>
Tested-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> [mediatek]
Tested-by: default avatarCharan Teja Kalla <quic_charante@quicinc.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Aneesh Kumar K V <aneesh.kumar@linux.ibm.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Brian Geffon <bgeffon@google.com>
Cc: Jan Alexander Steffens (heftig) <heftig@archlinux.org>
Cc: Lecopzer Chen <lecopzer.chen@mediatek.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Oleksandr Natalenko <oleksandr@natalenko.name>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Steven Barrett <steven@liquorix.net>
Cc: Suleiman Souhlal <suleiman@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent bb5e7f23

mm/vmscan.c

+2 −1
Original line number Diff line number Diff line
@@ -4656,6 +4656,7 @@ void lru_gen_look_around(struct page_vma_mapped_walk *pvmw) 
	pte_t *pte = pvmw->pte;

	unsigned long addr = pvmw->address;

	struct folio *folio = pfn_folio(pvmw->pfn);

	bool can_swap = !folio_is_file_lru(folio);

	struct mem_cgroup *memcg = folio_memcg(folio);

	struct pglist_data *pgdat = folio_pgdat(folio);

	struct lruvec *lruvec = mem_cgroup_lruvec(memcg, pgdat);
@@ -4704,7 +4705,7 @@ void lru_gen_look_around(struct page_vma_mapped_walk *pvmw) 
		if (!pte_young(ptent))

			continue;



		folio = get_pfn_folio(pfn, memcg, pgdat, !walk || walk->can_swap);

		folio = get_pfn_folio(pfn, memcg, pgdat, can_swap);

		if (!folio)

			continue;