Re: [PATCH 6/6] add documentation on proc.txt

From: Rob Landley
Date: Mon Apr 22 2013 - 11:48:53 EST


On 04/22/2013 03:45:06 AM, Minchan Kim wrote:
This patch adds documentation about new reclaim field in proc.txt

Cc: Rob Landley <rob@xxxxxxxxxxx>
Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx>
---
Documentation/filesystems/proc.txt | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)

diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt
index 488c094..c1f5ee4 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 +490,29 @@ To clear the soft-dirty bit

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

+The /proc/PID/reclaim is used to reclaim pages in this process.

Trivial nitpick: Either start with "The file" or just /proc/PID/reclaim

+To reclaim file-backed pages,
+ > echo 1 > /proc/PID/reclaim
+
+To reclaim anonymous pages,
+ > echo 2 > /proc/PID/reclaim
+
+To reclaim both pages,
+ > echo 3 > /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 4 addr size > /proc/PID/reclaim

Size is in bytes or pages? (I'm guessing bytes. It must be a multiple of pages?)

So the following examples are telling it to reclaim a specific page?

+To reclaim file-backed pages in address range,
+ > echo 4 $((1<<20) 4096 > /proc/PID/reclaim
+
+To reclaim anonymous pages in address range,
+ > echo 5 $((1<<20) 4096 > /proc/PID/reclaim
+
+To reclaim both pages in address range,
+ > echo 6 $((1<<20) 4096 > /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.

Otherwise, if the series goes in I'm fine with this going in with it.

Acked-by: Rob Landley <rob@xxxxxxxxxxx>

Rob--
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