aboutsummaryrefslogtreecommitdiff
path: root/Documentation/sysctl
diff options
context:
space:
mode:
authorZheng Liu <wenqing.lz@taobao.com>2013-11-12 15:08:30 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2013-11-13 12:09:11 +0900
commit715ea41e60277f28f84d6c937737350e00955d56 (patch)
treec8046aac7007ecb657f56fae897df195c2d2761b /Documentation/sysctl
parenta1aeb65a4c80d8e97eca8bcde02a5aeae11f6201 (diff)
downloadlinux-linaro-stable-715ea41e60277f28f84d6c937737350e00955d56.tar.gz
mm: improve the description for dirty_background_ratio/dirty_ratio sysctl
Now dirty_background_ratio/dirty_ratio contains a percentage of total avaiable memory, which contains free pages and reclaimable pages. The number of these pages is not equal to the number of total system memory. But they are described as a percentage of total system memory in Documentation/sysctl/vm.txt. So we need to fix them to avoid misunderstanding. Signed-off-by: Zheng Liu <wenqing.lz@taobao.com> Cc: Rob Landley <rob@landley.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation/sysctl')
-rw-r--r--Documentation/sysctl/vm.txt15
1 files changed, 10 insertions, 5 deletions
diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt
index 79a797eb3e87..1fbd4eb7b64a 100644
--- a/Documentation/sysctl/vm.txt
+++ b/Documentation/sysctl/vm.txt
@@ -119,8 +119,11 @@ other appears as 0 when read.
dirty_background_ratio
-Contains, as a percentage of total system memory, the number of pages at which
-the background kernel flusher threads will start writing out dirty data.
+Contains, as a percentage of total available memory that contains free pages
+and reclaimable pages, the number of pages at which the background kernel
+flusher threads will start writing out dirty data.
+
+The total avaiable memory is not equal to total system memory.
==============================================================
@@ -151,9 +154,11 @@ interval will be written out next time a flusher thread wakes up.
dirty_ratio
-Contains, as a percentage of total system memory, the number of pages at which
-a process which is generating disk writes will itself start writing out dirty
-data.
+Contains, as a percentage of total available memory that contains free pages
+and reclaimable pages, the number of pages at which a process which is
+generating disk writes will itself start writing out dirty data.
+
+The total avaiable memory is not equal to total system memory.
==============================================================