[SVN-4013] merge performance regression in 1.7 when target has no explicit mergeinfo

• Type: Bug
• Status: Closed
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 1.7.x
• Fix Version/s: 1.7.0
• Component/s: unknown
• Assignee: Paul Burba
• Reporter: Paul Burba
• Created: 07/Sep/11 16:55
• Updated: 27/Oct/18 16:30
• Resolved: 10/Oct/11 17:58

Description

Using the latest trunk build (), reverse merging a single revision from our own
trunk's history is faster in my ad hoc testing than with 1.6.17 *if* the target
has explicit mergeinfo:

(All WC targets are https://svn.apache.org/repos/asf/subversion/trunk@1166236)

### 1.6.18-dev(r1154735):

C:\SVN\src-trunk-7-1.6.WC>timethis svn merge
https://svn.apache.org/repos/asf/subversion/trunk -c-1127134 --accept postpone

TimeThis :  Command Line :  svn merge
https://svn.apache.org/repos/asf/subversion/trunk -c-1127134 --accept postpone
TimeThis :    Start Time :  Wed Sep 07 11:59:16 2011

--- Reverse-merging r1127134 into '.':
U    subversion\tests\cmdline\tree_conflict_tests.py
U    subversion\libsvn_wc\adm_ops.c
C    subversion\libsvn_client\add.c
Summary of conflicts:
  Text conflicts: 1

TimeThis :  Command Line :  svn merge
https://svn.apache.org/repos/asf/subversion/trunk -c-1127134 --accept postpone
TimeThis :    Start Time :  Wed Sep 07 11:59:16 2011
TimeThis :      End Time :  Wed Sep 07 11:59:28 2011
TimeThis :  Elapsed Time :  00:00:11.854

### With trunk@1166230:

C:\SVN\src-trunk>timethis svn merge
https://svn.apache.org/repos/asf/subversion/trunk -c-1127134 --accept postpone

TimeThis :  Command Line :  svn merge
https://svn.apache.org/repos/asf/subversion/trunk -c-1127134 --accept postpone
TimeThis :    Start Time :  Wed Sep 07 11:59:00 2011

--- Reverse-merging r1127134 into '.':
U    subversion\tests\cmdline\tree_conflict_tests.py
U    subversion\libsvn_wc\adm_ops.c
C    subversion\libsvn_client\add.c
--- Recording mergeinfo for reverse merge of r1127134 into '.':
 U   .
Summary of conflicts:
  Text conflicts: 1

TimeThis :  Command Line :  svn merge
https://svn.apache.org/repos/asf/subversion/trunk -c-1127134 --accept postpone
TimeThis :    Start Time :  Wed Sep 07 11:59:00 2011
TimeThis :      End Time :  Wed Sep 07 11:59:04 2011
TimeThis :  Elapsed Time :  00:00:04.468

### If the target has no explicit mergeinfo though, there is a problem:
### 1.6.18-dev(r1154735):

C:\SVN\src-trunk-7-1.6.WC>timethis svn merge
https://svn.apache.org/repos/asf/subversion/trunk/subversion subversion
-c-1127134 --accept postpone

TimeThis :  Command Line :  svn merge
https://svn.apache.org/repos/asf/subversion/trunk/subversion subversion
-c-1127134 --accept postpone
TimeThis :    Start Time :  Wed Sep 07 12:06:09 2011

--- Reverse-merging r1127134 into 'subversion':
U    subversion\tests\cmdline\tree_conflict_tests.py
U    subversion\libsvn_wc\adm_ops.c
C    subversion\libsvn_client\add.c
Summary of conflicts:
  Text conflicts: 1

TimeThis :  Command Line :  svn merge
https://svn.apache.org/repos/asf/subversion/trunk/subversion subversion
-c-1127134 --accept postpone
TimeThis :    Start Time :  Wed Sep 07 12:06:09 2011
TimeThis :      End Time :  Wed Sep 07 12:06:19 2011
TimeThis :  Elapsed Time :  00:00:10.040

### The same merge with trunk went on for 35 minutes before I stopped it:

C:\SVN\src-trunk>timethis svn merge
https://svn.apache.org/repos/asf/subversion/trunk/subversion subversion
-c-1127134 --accept postpone

TimeThis :  Command Line :  svn merge
https://svn.apache.org/repos/asf/subversion/trunk/subversion subversion
-c-1127134 --accept postpone
TimeThis :    Start Time :  Wed Sep 07 12:06:55 2011

^C