[reiserfs-list] Re: [OpenAFS-devel] more on the 2.2.18pre17 SMPcpu hog/etc.
Sun, 3 Dec 2000 18:34:45 -0500 (EST)
On 3 Dec 2000, Derek Atkins wrote:
> Hans Reiser <firstname.lastname@example.org> writes:
> > The AFS code needs to store the key (at least 64 bits of it), not
> > the inode number, or performance is doomed when interacting with
> > reiserfs.
> By the time that the AFS kernel code gets far enough to even obtain
> the "key", it's already opened the file. Unless there is a portable
> way to obtain the key from user-space (considering that we cannot
> presume that we're using Reiserfs).
> Basically, what happens is that at start-time the user-space code
> finds the inode number as I mentioned in the previous mail. Then it
> passes that to the kernel, and the kernel immediately opens the file
> and pretty much keeps the file opened. So, as long as the file inode
> is cached between the time the user-space code stat's the file and the
> kernel opens it, we're fine.
Not true. Cache files are opened as needed; they are not kept open
permanently. Only the CacheItems file and maybe the VolumeItems file
get that treatment.
-- Jeffrey T. Hutzelman (N3NHS) <email@example.com>
Sr. Research Systems Programmer
School of Computer Science - Research Computing Facility
Carnegie Mellon University - Pittsburgh, PA