Re: Faster resuming of suspend technology.

Andreas Mohr
2006-03-12T21:32:35Z

Hi,

[CC'd -ck list]

On Sat, Mar 11, 2006 at 02:04:10AM +0900, Jun OKAJIMA wrote:
>
>
> As you might know, one of the key technology of fast booting is suspending.
> actually, using suspending does fast booting. And very good point is
> not only can do booting desktop and daemons, but apps at once.
> but one big fault --- it is slow for a while after booted because of HDD thrashing.
> (I mention a term suspend as generic one, not refering only to Nigel Cunningham's one)
I think that is the case since swsusp AFAIR forces as many pages
as possible into swap and then appends some non-pageable parts
before shutting down.
Thus the system will resume with all processes fully residing
in swap space and the apps getting back to main memory
on demand only.

And... well... this sounds to me exactly like a prime task
for the newish swap prefetch work, no need for any other
special solutions here, I think.
We probably want a new flag for swap prefetch to let it know
that we just resumed from software suspend and thus need
prefetching to happen *much* faster than under normal
conditions for a short while, though (most likely by
enabling prefetching on a *non-idle* system for a minute).

Andreas Mohr