| Date | Thu, 18 Aug 2011 16:54:28 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH 6/7] mm: vmscan: Throttle reclaim if encountering too many dirty pages under writeback |
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On Wed, 10 Aug 2011 11:47:19 +0100 Mel Gorman <mgorman@suse.de> wrote:
> The percentage that must be in writeback depends on the priority. At > default priority, all of them must be dirty. At DEF_PRIORITY-1, 50% > of them must be, DEF_PRIORITY-2, 25% etc. i.e. as pressure increases > the greater the likelihood the process will get throttled to allow > the flusher threads to make some progress.
It'd be nice if the code comment were to capture this piece of implicit arithmetic. After all, it's a magic number and magic numbers should stick out like sore thumbs.
And.. how do we know that the chosen magic numbers were optimal?
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