[PATCH 21/31] huge tmpfs: show page team flag in pageflags

From: Hugh Dickins
Date: Tue Apr 05 2016 - 17:49:56 EST


From: Andres Lagar-Cavilla <andreslc@xxxxxxxxxx>

For debugging and testing.

Signed-off-by: Andres Lagar-Cavilla <andreslc@xxxxxxxxxx>
Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx>
---
This patchset has been based on v4.6-rc2: here we get a clash with
the addition of KPF_MOVABLE in current mmotm, not hard to fix up.

Documentation/vm/pagemap.txt | 2 ++
fs/proc/page.c | 6 ++++++
include/uapi/linux/kernel-page-flags.h | 3 ++-
tools/vm/page-types.c | 2 ++
4 files changed, 12 insertions(+), 1 deletion(-)

--- a/Documentation/vm/pagemap.txt
+++ b/Documentation/vm/pagemap.txt
@@ -71,6 +71,8 @@ There are four components to pagemap:
23. BALLOON
24. ZERO_PAGE
25. IDLE
+ 26. TEAM
+ 27. TEAM_PMD_MMAP (only if the whole team is mapped as a pmd at least once)

* /proc/kpagecgroup. This file contains a 64-bit inode number of the
memory cgroup each page is charged to, indexed by PFN. Only available when
--- a/fs/proc/page.c
+++ b/fs/proc/page.c
@@ -12,6 +12,7 @@
#include <linux/memcontrol.h>
#include <linux/mmu_notifier.h>
#include <linux/page_idle.h>
+#include <linux/pageteam.h>
#include <linux/kernel-page-flags.h>
#include <asm/uaccess.h>
#include "internal.h"
@@ -112,6 +113,11 @@ u64 stable_page_flags(struct page *page)
if (PageKsm(page))
u |= 1 << KPF_KSM;

+ if (PageTeam(page)) {
+ u |= 1 << KPF_TEAM;
+ if (page == team_head(page) && team_pmd_mapped(page))
+ u |= 1 << KPF_TEAM_PMD_MMAP;
+ }
/*
* compound pages: export both head/tail info
* they together define a compound page's start/end pos and order
--- a/include/uapi/linux/kernel-page-flags.h
+++ b/include/uapi/linux/kernel-page-flags.h
@@ -34,6 +34,7 @@
#define KPF_BALLOON 23
#define KPF_ZERO_PAGE 24
#define KPF_IDLE 25
-
+#define KPF_TEAM 26
+#define KPF_TEAM_PMD_MMAP 27

#endif /* _UAPILINUX_KERNEL_PAGE_FLAGS_H */
--- a/tools/vm/page-types.c
+++ b/tools/vm/page-types.c
@@ -133,6 +133,8 @@ static const char * const page_flag_name
[KPF_BALLOON] = "o:balloon",
[KPF_ZERO_PAGE] = "z:zero_page",
[KPF_IDLE] = "i:idle_page",
+ [KPF_TEAM] = "y:team",
+ [KPF_TEAM_PMD_MMAP] = "Y:team_pmd_mmap",

[KPF_RESERVED] = "r:reserved",
[KPF_MLOCKED] = "m:mlocked",