Messages in this thread | | | From | KOSAKI Motohiro <> | Subject | Re: [PATCH] documentation: clarify dirty_ratio and dirty_background_ratio description | Date | Thu, 9 Oct 2008 09:42:28 +0900 (JST) |
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> The current documentation of dirty_ratio and dirty_background_ratio is a > bit misleading. > > In the documentation we say that they are "a percentage of total system > memory", but the current page writeback policy, intead, is to apply the > percentages to the dirtyable memory, that means free pages + reclaimable > pages. > > Better to be more explicit to clarify this concept. > > Signed-off-by: Andrea Righi <righi.andrea@gmail.com>
looks good to me.
> --- > Documentation/filesystems/proc.txt | 11 ++++++----- > 1 files changed, 6 insertions(+), 5 deletions(-) > > diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt > index f566ad9..be69c8b 100644 > --- a/Documentation/filesystems/proc.txt > +++ b/Documentation/filesystems/proc.txt > @@ -1380,15 +1380,16 @@ causes the kernel to prefer to reclaim dentries and inodes. > dirty_background_ratio > ---------------------- > > -Contains, as a percentage of total system memory, the number of pages at which > -the pdflush background writeback daemon will start writing out dirty data. > +Contains, as a percentage of the dirtyable system memory (free pages + > +reclaimable pages), the number of pages at which the pdflush background > +writeback daemon will start writing out dirty data. > > 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 the dirtyable system memory (free pages + > +reclaimable pages), the number of pages at which a process which is generating > +disk writes will itself start writing out dirty data. > > dirty_writeback_centisecs > -------------------------
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