[Devel] Re: How Inactive may be much greather than cached?

[Vasily Averin]

Nick Piggin wrote:
> Hi,
> 
> On Thursday 18 October 2007 16:24, Vasily Averin wrote:
>> Hi all,
>>
>> could anybody explain how "inactive" may be much greater than "cached"?
>> stress test (http://weather.ou.edu/~apw/projects/stress/) that writes into
>> removed files in cycle puts the node to the following state:
>>
>> MemTotal: 16401648 kB
>> MemFree: 636644 kB
>> Buffers: 1122556 kB
>> Cached: 362880 kB
>> SwapCached: 700 kB
>> Active: 1604180 kB
>> Inactive: 13609828 kB
>>
>> At the first glance memory should be freed on file closing, nobody refers
>> to file and ext3_delete_inode() truncates inode. We can see that memory is
>> go away from "cached", however could somebody explain why it become
>> "invalid" instead be freed? Who holds the references to these pages?
> 
> Buffers, swap cache, and anonymous.

But buffers and swap cache are low (1.1 Gb and 700kB in this example) and
anonymous should go away when process finished.