From 0a71649cb724ab97df26baa7731ac31d2364bfe5 Mon Sep 17 00:00:00 2001 From: Naoya Horiguchi Date: Thu, 17 Mar 2016 14:17:44 -0700 Subject: [PATCH] /proc/kpageflags: return KPF_SLAB for slab tail pages Currently /proc/kpageflags returns just KPF_COMPOUND_TAIL for slab tail pages, which is inconvenient when grasping how slab pages are distributed (userspace always needs to check which kind of tail pages by itself). This patch sets KPF_SLAB for such pages. With this patch: $ grep Slab /proc/meminfo ; tools/vm/page-types -b slab Slab: 64880 kB flags page-count MB symbolic-flags long-symbolic-flags 0x0000000000000080 16220 63 _______S__________________________________ slab total 16220 63 16220 pages equals to 64880 kB, so returned result is consistent with the global counter. Signed-off-by: Naoya Horiguchi Reviewed-by: Vladimir Davydov Cc: Konstantin Khlebnikov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/proc/page.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/proc/page.c b/fs/proc/page.c index 0be626d85331..712f1b9992cc 100644 --- a/fs/proc/page.c +++ b/fs/proc/page.c @@ -160,6 +160,8 @@ u64 stable_page_flags(struct page *page) u |= kpf_copy_bit(k, KPF_LOCKED, PG_locked); u |= kpf_copy_bit(k, KPF_SLAB, PG_slab); + if (PageTail(page) && PageSlab(compound_head(page))) + u |= 1 << KPF_SLAB; u |= kpf_copy_bit(k, KPF_ERROR, PG_error); u |= kpf_copy_bit(k, KPF_DIRTY, PG_dirty); -- 2.20.1