On Fri, May 12, 2006 at 06:33:00PM +0200, Roch Bourbonnais - Performance Engineering wrote: > Directio is non-posix anyway and given that people have been > train to inform the system that the cache won't be useful, > that it's a hard problem to detect automatically, let's > avoid the copy and save memory all at once for the read path. > > We could use the directio() call for that ...
I had no idea about directio(3C)! We might want an interface for the app to know what the natural block size of the file is, so it can read at proper file offsets. Of course, if that block size is smaller than the ZFS filesystem record size then ZFS may yet grow it. How to deal with this? (One option: don't grow it as long as an app has turned direct I/O on for a fildes and the fildes remains open.) Nico -- _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
