On Fri, 2006-03-24 at 06:32 -0800, Valerie Henson wrote:
> On Wed, Mar 22, 2006 at 05:55:03PM -0800, Andrew Morton wrote:
> > Valerie Henson <[email protected]> wrote:
> > >
> > > ext2 is simpler and faster than ext3 in many cases. This is sort of
> > > cheating; ext2 is simpler and faster because it makes no effort to
> > > maintain on-disk consistency and can skip annoying things like, oh,
> > > reserving space in the journal. I am looking for ways to make ext2
> > > cheat even more.
> > >
> >
> > But it might be feasible to knock up an ext3-- in which all the journal
> > operations are stubbed out.
>
> Hmm... Could we get the mark_buffer_dirty/mark_inode_dirty logic
> right? Probably create a list in the stubbed journal functions and
> then mark them dirty in the journal close? However, half the reason
> I'm working on ext2 is the simplicity of the code - stubbing it out
> would solve the performance problem but not the complexity problem.
I don't know the ext3 journaling code at all, so this may or may not be
useful, but jfs has a nointegrity mode that disables writing to the
journal. To keep it simple, I execute all of the journaling code as
normal except that when it is time to actually submit I/O to the
journal, I call the end_io routine directly. (I first set bio->bi_size
= 0 to make it look like the I/O was successful.) There is a bit more
cpu overhead than if we stubbed out all the journaling code, but it's a
lot safer not to have to worry about different paths of execution.
> Note that ext3's habit of clearing indirect blocks on truncate would
> break some things I want to do in the future. (Insert secret plans
> here.)
I can't comment on that. :-)
--
David Kleikamp
IBM Linux Technology Center
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
