On Sun, Apr 08, 2007 at 09:10:21PM +0900, YAMAMOTO Takashi wrote:
> > UVMPAGER_ASYNCIO_START is used in
> > genfs_getpages() to indicate the start of an async i/o transaction.
> 
> let me cite my original question:
> 
> > > +/* Flags to uvm_io_done */
> > > +#define UVMPAGER_SYNCIO_DONE       0x01    /* Synch i/o has completed */
> > > +#define UVMPAGER_ASYNCIO_START     0x02    /* Asynch i/o started */
> > > +#define UVMPAGER_ASYNCIO_DONE      0x03    /* Asynch i/o has completed */
> > > +
> >
> > can you explain "Asynch i/o started"?
> > to me, it seems to be used only when async getpages found all pages cached.
> > ie. no i/o is started.
> 
> in particular, i don't understand which i/o you are talking about.
> 

Ah, I was being dense.  Yes, you are right - the only time that
"asynch i/o started" would be used is if the pages are already
resident.  I didn't notice that before, good catch.  Perhaps I should
rename UVMPAGER_ASYNCIO_START to UVMPAGER_PAGES_RESIDENT or something
like that.

-- 
Brett Lymn