'svn commit' recent slowdown

Recently (last week or so), I've noticed that 'svn commit' has gotten
*really* slow. As in, it takes a full 30 seconds for 'svn commit' to return
when asked to perform a no-op commit of my Subversion trunk directory.

I was able to discern through code-stepping that the lion's share of the
time spent was in the harvest_committables() code. I sorta suspected
svn_wc__node_get_children_of_working_node() as the problem point, given that
that's the only thing that's really changed in the harvest_committables()
codepath recently, but I didn't really know how to verify that.

So today I started trying to mess with callgrind a bit. Here's some heavily
filtered output from callgrind_annotate on a no-op commit of just our
trunk/subversion/tests/cmdline directory (committing at higher levels was
taking FOREVER while profiling):

4,357,656,366 112,781 756 subversion/svn/main.c:main
4,352,930,262 112,657 753 subversion/svn/commit-cmd.c:svn_cl__commit
4,350,334,930 112,511 751
subversion/libsvn_client/commit.c:svn_client_commit5
4,349,499,552 112,341 751
subversion/libsvn_client/commit_util.c:svn_client__harvest_committables
4,348,470,026 112,079 748
subversion/libsvn_client/commit_util.c:harvest_committables
4,269,103,898 108,354 729 subversion/libsvn_subr/sqlite.c:svn_sqlite__step
4,189,859,746 85,024 604
subversion/libsvn_wc/node.c:svn_wc__node_get_children_of_working_node
4,179,862,166 83,354 592
subversion/libsvn_wc/wc_db.c:svn_wc__db_read_children_of_working_node
4,179,834,710 83,354 592 subversion/libsvn_wc/wc_db.c:gather_children2
4,179,798,573 83,354 592
subversion/libsvn_wc/wc_db.c:add_children_to_hash
4,046,859,894 116,411 761
subversion/libsvn_client/commit_util.c:harvest_committables'2
   90,828,539 16,308 85
subversion/libsvn_wc/wc_db.c:svn_wc__db_read_info
   83,508,483 18,868 101 subversion/libsvn_wc/wc_db.c:read_info
   32,672,951 492 6
subversion/libsvn_wc/wc_db_wcroot.c:svn_wc__db_wcroot_parse_local_abspath
   29,042,308 3,196 17
subversion/libsvn_wc/wc_db.c:svn_wc__db_read_props
   26,587,135 3,253 17
subversion/libsvn_wc/wc_db_txn.c:svn_wc__db_with_txn
   26,561,409 3,253 17
subversion/libsvn_subr/sqlite.c:svn_sqlite__with_lock
[...]

I *think* this supports my hypothesis regarding
svn_wc__node_get_children_of_working_node(). I have yet to try reverting
the introduction of this function to see if that helps, but (because I'm out
of time for today) I wanted to at least get this data out there for someone
else to see.

-- 
C. Michael Pilato <cmpilato_at_collab.net>
CollabNet   <>   www.collab.net   <>   Distributed Development On Demand