Re: Linux-2.5.17

[Dave McCracken <dmccr@us.ibm.com>]

--On Tuesday, May 21, 2002 08:21:56 PM -0700 Linus Torvalds
<torvalds@transmeta.com> wrote:

> The problem is just finding a _good_ context to switch to. We can do this
> two different ways:
> 
> (...)
> 
>  - my preferred solution: speculatively find _some_ process (preferably
>    one that we are likely to schedule next), and use that process's
>    "active_mm" to do a "switch_mm()" into (and set that to "current->mm")
> 
> The speculative thing has the problem of finding a good process, but I
> would suggest something along the lines of:
> 
>  - take the first process in the run-queue on the current CPU.
>  - if there is no process on th erun-queue, take our parent

What would be the incremental cost of just switching to init_mm?  Granted,
it's likely to require switching again when you schedule, but this is the
exit path.  It could be a fallback if nothing else looks good.

Dave McCracken

======================================================================
Dave McCracken          IBM Linux Base Kernel Team      1-512-838-3059
dmccr@us.ibm.com                                        T/L   678-3059