I was able to capture a profile from svn (after remembering I have to link statically). I compiled with "-pg -O0" Here is the top of the file:
Each sample counts as 0.01 seconds. % cumulative self self total time seconds seconds calls s/call s/call name 88.88 133.49 133.49 2002891836 0.00 0.00 svn_diff__snake 5.97 142.45 8.96 56 0.16 2.54 svn_diff(long, char, short) 1.98 145.42 2.97 4163001 0.00 0.00 MD5Transform 0.41 146.04 0.62 4163001 0.00 0.00 Decode Is it OK to attach the full report to this user list? The resulting text file is 1.3MB and I wasn't sure if the list would tolerate an attachment of that size. Cheers, Kyle On Sat, Oct 1, 2011 at 7:55 PM, Daniel Shahaf <d...@daniel.shahaf.name>wrote: > gprof is what I'm familiar with (nutshell: compile with 'gcc -pg' and > read gmon.out). There are no specific profiling docs for svn; if you > need more specific advice please post to the dev@ list. Thanks! > > Kyle Leber wrote on Sat, Oct 01, 2011 at 19:33:10 -0400: > > What method of profiling do you recommend? I have used gprof previously > > (it's been awhile) but am not familiar with the subversion project source > > code and build setup. Is the a online guide or wiki describing the > > preferred setup for performing this? > > > > Kyle > > > > On Sat, Oct 1, 2011 at 3:10 PM, Daniel Shahaf <d...@daniel.shahaf.name > >wrote: > > > > > 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 <kyle.le...@gmail.com> > wrote: > > > > > On Fri, Sep 30, 2011 at 7:15 PM, Johan Corveleyn < > jcor...@gmail.com> > > > wrote: > > > > >> > > > > >> On Fri, Sep 30, 2011 at 3:29 PM, Kyle Leber <kyle.le...@gmail.com > > > > > 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 > > > >