Re: [RFC] fsblock

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Tue, 10 Jul 2007, Nick Piggin wrote:

> > Hmmm.... I did not notice that yet but then I have not done much work 
> > there.
> 
> Notice what?

The bad code for the buffer heads.

> > > - A real "nobh" mode. nobh was created I think mainly to avoid problems
> > >   with buffer_head memory consumption, especially on lowmem machines. It
> > >   is basically a hack (sorry), which requires special code in filesystems,
> > >   and duplication of quite a bit of tricky buffer layer code (and bugs).
> > >   It also doesn't work so well for buffers with non-trivial private data
> > >   (like most journalling ones). fsblock implements this with basically a
> > >   few lines of code, and it shold work in situations like ext3.
> > 
> > Hmmm.... That means simply page struct are not working...
> 
> I don't understand you. jbd needs to attach private data to each bh, and
> that can stay around for longer than the life of the page in the pagecache.

Right. So just using page struct alone wont work for the filesystems.

> There are no changes to the filesystem API for large pages (although I
> am adding a couple of helpers to do page based bitmap ops). And I don't
> want to rely on contiguous memory. Why do you think handling of large
> pages (presumably you mean larger than page sized blocks) is strange?

We already have a way to handle large pages: Compound pages.

> Conglomerating the constituent pages via the pagecache radix-tree seems
> logical to me.

Meaning overhead to handle each page still exists? This scheme cannot 
handle large contiguous blocks as a single entity?

-
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Index of Archives]     [Linux Ext4 Filesystem]     [Union Filesystem]     [Filesystem Testing]     [Ceph Users]     [Ecryptfs]     [AutoFS]     [Kernel Newbies]     [Share Photos]     [Security]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux Cachefs]     [Reiser Filesystem]     [Linux RAID]     [Samba]     [Device Mapper]     [CEPH Development]
  Powered by Linux