Re: [PATCH] splice support #2

[Jens Axboe <axboe@suse.de>]

On Thu, Mar 30 2006, Ingo Molnar wrote:
> 
> * Jens Axboe <axboe@suse.de> wrote:
> 
> > On Thu, Mar 30 2006, Ingo Molnar wrote:
> > > 
> > > * Jens Axboe <axboe@suse.de> wrote:
> > > 
> > > > > I agree with the purpose of making sys_splice() generic and in 
> > > > > particular usable in scripts/shells where pipes are commonly used, but 
> > > > > we should also fulfill the original promise (outlined 15 years ago or 
> > > > > so) and not limit this to pipes. That way i could improve TUX to make 
> > > > > use of it for example ;)
> > > > 
> > > > There's absolutely no reason why we can't add fd -> fd splicing as 
> > > > well, so no worries. Right now we just require a pipe transport. It's 
> > > > extendable :-)
> > > 
> > > ok :) I think this code should be merged into v2.6.17 - it's very clean 
> > > and unintrusive.
> > 
> > I hope so, too. I'll post a hopefully finished patch real soon, and 
> > then the move pages addon afterwards (which works now).
> 
> what does the move pages addon do? pagecache->pagecache transfer?

Precisely, if you do file1 | file2 splicing, you can move the pages to
file2's address space. So say I do splice-cp file1 file2, I would only
have file2 contents in page cache aftwards. And I'd save a memcpy of all
the data.

-- 
Jens Axboe