Re: madvise(2) MADV_SEQUENTIAL behavior

[Chris Snook <csnook@redhat.com>]

Rik van Riel wrote:
> On Thu, 17 Jul 2008 16:14:29 +1000
> Nick Piggin <nickpiggin@yahoo.com.au> wrote:
> 
>>> It might encourage user space applications to start using
>>> FADV_SEQUENTIAL or FADV_NOREUSE more often (as it would become
>>> worthwhile to do so), and if they do (especially cron jobs), the problem
>>> of the slow desktop in the morning would progressively solve itself.
>> The slow desktop in the morning should not happen even without such a
>> call, because the kernel should not throw out frequently used data (even
>> if it is not quite so recent) in favour of streaming data.
>>
>> OK, I figure it doesn't do such a good job now, which is sad, 
> 
> Do you have any tests in mind that we could use to decide
> whether the patch I posted Tuesday would do a decent job
> at protecting frequently used data from streaming data?
> 
> http://lkml.org/lkml/2008/7/15/465
> 

1) start up a memory-hogging Java app
2) run a full-system backup

If it works well, the Java app shouldn't slow down much.

-- Chris