Re: [Ext2-devel] [PATCH] concurrent block allocation for ext2 against 2.5.64

[Theodore Ts'o]

On Thu, Mar 13, 2003 at 10:39:48AM -0700, Andreas Dilger wrote:
> Sadly, we are constantly diverging the ext2/ext3 codebases.  Lots of
> features are going into ext3, but lots of fixes/improvements are only
> going into ext2.  Is ext3 holding BKL for doing journal_start() still?
> 
> Looking at ext3_prepare_write() we grab the BKL for doing journal_start()
> and for journal_stop(), but I don't _think_ we need BKL for journal_stop()
> do we?  We may or may not need it for the journal_data case, but that is
> not even working right now I think.

We badly need to remove the BKL from ext3; it's the source of massive
performance problems for ext3 on larger machines.  

Stephen, you were telling me a week or two ago that there were some
subtle issues involved with BKL removal from the jbd layer --- could
you give us a quick summary of what landminds are there for whoever
wants to try to tackle the ext3/jbd BKL removal?

						- Ted