Re: cache regresions with 2.6.1x ?

[Andrew Morton <akpm@osdl.org>]

jerome lacoste <jerome.lacoste@gmail.com> wrote:
>
> I am on a Dell Inspiron 8100 laptop with 512 M and 1G disk cache. I
>  usually have at least 4 big applications running simultaneously: a
>  Java IDE, firefox, firefox and X. All that under the Gnome desktop.
> 
>  I've sometimes seen periods where my laptop goes kind of nuts. While
>  the cpu is still at 0%, the workload goes to 100% (as shown in the
>  gnome process monitor) (I haven't checked in other means, e.g. top or
>  /proc info as my machine is unusable).
> 
>  But with my latest upgrade to 2.6.12 from 2.6.10, the hanging happens
>  much more often. It lasts for over 30 seconds.
> 
>  Could this hanging be related to swapping?
>  Are there any VM regression lately that would make a kernel less
>  appropriate for desktop use?
>  How can I investigate that further?

10-20 lines of `vmstat 1' output while it's happening would help.

If lots of system time is being consumed then the next step is to generate
a kernel profile - Documentation/basic_profiling.txt