Re: SVN 1.7/1.8 "commit after delete" performance issue

Alexander Lüders <alu_at_entimo.de> writes:

> 1) svnadmin create testrepo
> 2) svnserve --listen-host=localhost --listen-port=4444 --root=testrepo
> 3) svn co svn://localhost:4444/ wc
> 4) create file testXXX.html in <wc>
> 5) svn add wc/testXXX.html
> 6) svn commit wc/testXXX.html
> 7) svn delete wc/testXXX.html
> 8) svn commit wc/testXXX.html
>
> The steps 4-8 in the scenario were repeated for 30 files. The time needed for each operation was meaned over these 30 runs.
> The eigth step is taking around 11 times longer in 1.7/1.8 compared to 1.6.x.
> Here are my results:
>
> Collabnet Subversion 1.6.23-1 32bit installer:
> +++++++++++++++++++++ Results ++++++++++++++++++++++++++
> create: 1.930.064 nanoseconds
> add: 33.922.540 nanoseconds
> commitadd: 94.885.332 nanoseconds
> delete: 35.964.514 nanoseconds
> commitdelete: 88.359.041 nanoseconds
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>
> Collabnet Subversion 1.7.10-1 32bit installer:
> +++++++++++++++++++++ Results ++++++++++++++++++++++++++
> create: 1,179,124 nanoseconds
> add: 33,794,865 nanoseconds
> commitadd: 91,458,958 nanoseconds
> delete: 35,703,185 nanoseconds
> commitdelete: 1,002,148,220 nanoseconds
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++

That's about 1s which leads me to suspect svn_io_sleep_for_timestamps.

Using a debugger I can see that in 1.6 the path passed to
svn_io_sleep_for_timestamps is the parent directory which still exists
in the working copy, while in 1.8 the path is the deleted file itself.
Passing the deleted file means that the path based optimisations are not
available in 1.7/1.8 and so svn_io_sleep_for_timestamps sleeps for
longer.

-- 
Philip Martin | Subversion Committer
WANdisco | Non-Stop Data