[PATCH v2 6/6] add documentation on proc.txt

Minchan Kim
2013-04-24T01:42:15Z

This patch adds stuff about new reclaim field in proc.txt

Cc: Rob Landley <rob@landley.net>
Signed-off-by: Minchan Kim <minchan@kernel.org>
---

Rob, I didn't add your Acked-by because interface was slight changed.
I hope you give Acke-by after review again.
Thanks.

Documentation/filesystems/proc.txt | 22 ++++++++++++++++++++++
mm/Kconfig | 7 +------
2 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt
index 488c094..1411ad0 100644
--- a/Documentation/filesystems/proc.txt
+++ b/Documentation/filesystems/proc.txt
@@ -136,6 +136,7 @@ Table 1-1: Process specific entries in /proc
maps Memory maps to executables and library files (2.4)
mem Memory held by this process
root Link to the root directory of this process
+ reclaim Reclaim pages in this process
stat Process status
statm Process memory status information
status Process status in human readable form
@@ -489,6 +490,27 @@ To clear the soft-dirty bit

Any other value written to /proc/PID/clear_refs will have no effect.

+The file /proc/PID/reclaim is used to reclaim pages in this process.
+To reclaim file-backed pages,
+ > echo file > /proc/PID/reclaim
+
+To reclaim anonymous pages,
+ > echo anon > /proc/PID/reclaim
+
+To reclaim all pages,
+ > echo all > /proc/PID/reclaim
+
+Also, you can specify address range of process so part of address space
+will be reclaimed. The format is following as
+ > echo addr size-byte > /proc/PID/reclaim
+
+NOTE: addr should be page-aligned.
+
+Below is example which try to reclaim 2 pages from 0x100000.
+
+To reclaim both pages in address range,
+ > echo $((1<<20) 8192 > /proc/PID/reclaim
+
The /proc/pid/pagemap gives the PFN, which can be used to find the pageflags
using /proc/kpageflags and number of times a page is mapped using
/proc/kpagecount. For detailed explanation, see Documentation/vm/pagemap.txt.
diff --git a/mm/Kconfig b/mm/Kconfig
index 314bf49..9d6b306 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -486,9 +486,4 @@ config PROCESS_RECLAIM
default n
help
It allows to reclaim pages of the process by /proc/pid/reclaim.
-
- (echo file > /proc/PID/reclaim) reclaims file-backed pages only.
- (echo anon > /proc/PID/reclaim) reclaims anonymous pages only.
- (echo all > /proc/PID/reclaim) reclaims all pages.
-
- Any other vaule is ignored.
+ See Documentation/filesystem/proc.txt for more details.
--
1.8.2