linux_dsm_epyc7002/include/uapi/linux/kernel-page-flags.h
Vladimir Davydov f074a8f49e proc: export idle flag via kpageflags
As noted by Minchan, a benefit of reading idle flag from /proc/kpageflags
is that one can easily filter dirty and/or unevictable pages while
estimating the size of unused memory.

Note that idle flag read from /proc/kpageflags may be stale in case the
page was accessed via a PTE, because it would be too costly to iterate
over all page mappings on each /proc/kpageflags read to provide an
up-to-date value.  To make sure the flag is up-to-date one has to read
/sys/kernel/mm/page_idle/bitmap first.

Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Reviewed-by: Andres Lagar-Cavilla <andreslc@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Greg Thelen <gthelen@google.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-10 13:29:01 -07:00

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C

#ifndef _UAPILINUX_KERNEL_PAGE_FLAGS_H
#define _UAPILINUX_KERNEL_PAGE_FLAGS_H
/*
* Stable page flag bits exported to user space
*/
#define KPF_LOCKED 0
#define KPF_ERROR 1
#define KPF_REFERENCED 2
#define KPF_UPTODATE 3
#define KPF_DIRTY 4
#define KPF_LRU 5
#define KPF_ACTIVE 6
#define KPF_SLAB 7
#define KPF_WRITEBACK 8
#define KPF_RECLAIM 9
#define KPF_BUDDY 10
/* 11-20: new additions in 2.6.31 */
#define KPF_MMAP 11
#define KPF_ANON 12
#define KPF_SWAPCACHE 13
#define KPF_SWAPBACKED 14
#define KPF_COMPOUND_HEAD 15
#define KPF_COMPOUND_TAIL 16
#define KPF_HUGE 17
#define KPF_UNEVICTABLE 18
#define KPF_HWPOISON 19
#define KPF_NOPAGE 20
#define KPF_KSM 21
#define KPF_THP 22
#define KPF_BALLOON 23
#define KPF_ZERO_PAGE 24
#define KPF_IDLE 25
#endif /* _UAPILINUX_KERNEL_PAGE_FLAGS_H */