mm: fix KPF_SWAPCACHE in /proc/kpageflags

Commit 6326fec ("mm: Use owner_priv bit for PageSwapCache, valid when PageSwapBacked") aliased PG_swapcache to PG_owner_priv_1 (and depending on PageSwapBacked being true). As a result, the KPF_SWAPCACHE bit in '/proc/kpageflags' should now be synthesized, instead of being shown on unrelated pages which just happen to have PG_owner_priv_1 set. Signed-off-by: Hugh Dickins <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Nicholas Piggin <[email protected]> Cc: Wu Fengguang <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
laijs · Feb 7, 2017 · b678912 · b678912
1 parent a524c21
commit b678912
Showing 1 changed file with 2 additions and 1 deletion.
diff --git a/fs/proc/page.c b/fs/proc/page.c
@@ -173,7 +173,8 @@ u64 stable_page_flags(struct page *page)
 	u |= kpf_copy_bit(k, KPF_ACTIVE,	PG_active);
 	u |= kpf_copy_bit(k, KPF_RECLAIM,	PG_reclaim);
 
-	u |= kpf_copy_bit(k, KPF_SWAPCACHE,	PG_swapcache);
+	if (PageSwapCache(page))
+		u |= 1 << KPF_SWAPCACHE;
 	u |= kpf_copy_bit(k, KPF_SWAPBACKED,	PG_swapbacked);
 
 	u |= kpf_copy_bit(k, KPF_UNEVICTABLE,	PG_unevictable);