Johan Corveleyn wrote on Sat, Oct 01, 2011 at 20:47:29 +0200: > [ Please do not top-post on this list, i.e. please put your reply > below or inline. More below ... ] > > On Sat, Oct 1, 2011 at 6:49 PM, Kyle Leber <[email protected]> wrote: > > On Fri, Sep 30, 2011 at 7:15 PM, Johan Corveleyn <[email protected]> wrote: > >> > >> On Fri, Sep 30, 2011 at 3:29 PM, Kyle Leber <[email protected]> wrote: > >> > I've encountered what I think is a problem with subversion, but I'm not > >> > completely sure (and according to the online instructions I should bring > >> > it > >> > up here prior to filing a bug). > >> > >> Actually, the instructions on > >> http://subversion.apache.org/issue-tracker.html say that you should > >> send your report to users@, not dev@. So I'm adding users@. Please > >> drop dev@ from any further replies. > >> > >> > Basically, we're trying to merge a rather large collection of > >> > fixes back in our trunk. I check out a fresh copy of the trunk, > >> > then use the merge syntax: svn merge https://path/to/my/branch . > >> > > >> > This generally churns along just fine, but we occasionally get > >> > hung up on medium sized binary files where the svn client jumps > >> > to 100% cpu usage and sits on it for 3+ hours before moving on to > >> > the next file. These files are anywhere from 3-10MB in size, so > >> > not ridiculously huge. We generally have these files marked as > >> > octet stream, but changing to text did not help the situation > >> > when we tried that. > >> > > >> > I did find an old forum discussion about a potential issue that > >> > could be related. I was wondering if this was ever addressed and > >> > could it still be the same problem. Link is here: > >> > http://www.svnforum.org/threads/36123-Slow-SVN-merge > >> > > >> > I'm using svn client 1.6.12. I looked at the online change log > >> > up through the 1.7 alphas and didn't see any bug fixes that > >> > sounded relevant. > >> > >> This could be a relevant change (listed in the 1.7 release notes, not > >> in the change log): > >> > >> http://subversion.apache.org/docs/release-notes/1.7.html#diff-optimizations > >> > >> Can you please try one of the 1.7 pre-release binaries, and see if it > >> helps? See http://subversion.apache.org/packages.html#pre-release > >> > > Thanks, Johan. I tested with 1.7rc4 and it did not make any perceptible > > difference. Anything else I can try? > > Hm, that's unfortunate. > > Actually, it was to be expected that this wouldn't help, because the > diff-optimizations in 1.7 only play a role when merging text files > (and diffing and blaming). And you said those > "files-that-make-merge-hang" are generally marked as octet-stream, and > changing them to text made no difference. > > That seems to indicate that the 100% cpu usage on the client isn't > spent in the diff code (unlike the forum thread that you linked to, > where the poster tracked it down to libsvn_diff/lcs.c --- he would > definitely have been helped by the 1.7 improvements). >
What does 'svn merge' do for binary files? I checked svn_wc__merge() a few months ago and for binary files all it knew to do was (a) if mine == merge-left then set merged := merge-right (b) invoke the configured diff3-cmd (c) raise a conflict but it didn't do any line-based merge (per Johan's second response). > So there's another reason. Maybe it has something to do with (lots of) > subtree mergeinfo? Can you verify if there is a lot of svn:mergeinfo > on directories and files all over the place? > > Also: can you tell us what version is running on the server? > > Maybe other people on this list have had similar experiences, and can > give some suggestions? > Another line of thought: the algorithm for computing binary deltas changed a few years ago, and I recall reading (on old bug reports?) about some cases in which the delta combiner would be inefficient for deltas generated by old servers --- i.e., it would be expensive to 'svn cat' files that were committed to old servers in repositories that haven't been dumped/loaded by a newer server. In any case: can you run the merge under a profiler and tell us in what function(s) time is spent? Daniel > -- > Johan
