Re: why swap at all?

[Nick Piggin]

Anthony DiSante wrote:
> Nick Piggin wrote:
>
> > The VM doesn't always get it right, and to make matters worse, desktop
> > users don't appreciate their long running jobs finishing earlier, but
> > *hate* having to wait a few seconds for a window to appear if it hasn't
> > been used for 24 hours.
>
>
> Come on, that is quite an exaggeration.  It can happen in a span of 
> minutes -- after rsyncing a dir to a backup dir, for example, which 
> fills ram rather quickly with cache I'll never use again.  Or after 
> configuring and compiling a package, which does the same thing.

rsync is something known to break the VM's use-once heuristics.
I'm looking at that.

> As you said, the VM doesn't, in fact, always get it right.  If 512MB 
> worked before when it was half swap, 512MB of pure ram will work too, 
> only faster.  I don't see how adding more swap at that point could 
> increase performance unless you are keeping your ram full of non-cached 
> pages, and that's never the case for me -- my ram is almost always half 
> cached pages.

It can.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/