Messages in this thread | | | Date | Fri, 05 Apr 2013 08:05:28 +0800 | From | Will Huck <> | Subject | Re: [PATCH 01/10] mm: vmscan: Limit the number of pages kswapd reclaims at each priority |
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Hi Rik, On 03/22/2013 09:01 PM, Rik van Riel wrote: > On 03/22/2013 12:59 AM, Will Huck wrote: >> Hi Rik, >> On 03/22/2013 11:56 AM, Will Huck wrote: >>> Hi Rik, >>> On 03/22/2013 11:52 AM, Rik van Riel wrote: >>>> On 03/21/2013 08:05 PM, Will Huck wrote: >>>> >>>>> One offline question, how to understand this in function >>>>> balance_pgdat: >>>>> /* >>>>> * Do some background aging of the anon list, to give >>>>> * pages a chance to be referenced before reclaiming. >>>>> */ >>>>> age_acitve_anon(zone, &sc); >>>> >>>> The anon lrus use a two-handed clock algorithm. New anonymous pages >>>> start off on the active anon list. Older anonymous pages get moved >>>> to the inactive anon list. >>> >>> The file lrus also use the two-handed clock algorithm, correct? >> >> After reinvestigate the codes, the answer is no. But why have this >> difference? I think you are the expert for this question, expect your >> explanation. :-) > > Anonymous memory has a smaller amount of memory (on the order > of system memory), most of which is or has been in a working > set at some point. > > File system cache tends to have two distinct sets. One part > are the frequently accessed files, another part are the files > that are accessed just once or twice. > > The file working set needs to be protected from streaming > IO. We do this by having new file pages start out on the
Is there streaming IO workload or benchmark?
> inactive file list, and only promoted to the active file > list if they get accessed twice. > >
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