Commit 715ea41e authored by Zheng Liu's avatar Zheng Liu Committed by Linus Torvalds
Browse files

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: default avatarZheng Liu <wenqing.lz@taobao.com>
Cc: Rob Landley <rob@landley.net>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent a1aeb65a

Documentation/sysctl/vm.txt

+10 −5
Original line number Diff line number Diff line
@@ -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.



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@@ -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.



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