Hi Stefan, Stefan Fuhrmann writes: > My measurements seem to support what Philip wrote: > The expensive part is run on the server. Even with my > optimized server, the svnrdump CPU usage is less than > the time taken by the server. Some numbers (hot file > cache): > > svnadmin dump > 1.7 trunk 70s real 66s user 4s system > perf-branch 30s real 28s user 2s system > > 1.7 trunk svnrdump > ra-local 88s real 81s user 7s system > svn: (1.7 trunk) 99s real 6s user 4s system > svn: (perf-branch, cold) 72s real 5s user 6s system > svn: (perf-branch, hot) 17s real 5s user 5s system > > Thus, svnrdump is slower only for ra-local where it is > of no particular use in the first place. To really speed > things up, the caching infrastructure from the performance > branch should be merged into /trunk.
Wow, that looks awesome. Yeah, Daniel suggested that I run svnrdump against your perf branch yesterday, but I wasn't able to get your branch to build: subversion/libsvn_subr/svn_file_handle_cache.c:890: error: 'svn_file_handle_cache_t' has no member named 'mutex' What exactly are the changes that "hot" introduces- can you point me to the specific revision numbers that we intend to merge? > >@Stefan: Thoughts on hacking APR hashtables directly? > > > Are you sure?! Which operation is the most expensive one > and how often is it called? Who calls it and why? My bad. I got muddled up when using ra_local: when I saw lots of MD5 functions, I assumed it had to do something with the hashtable since the checksum was caculated by server-side. The profiler profiled both server-side and client-side. Over svn://, I got a much cleaner output. The new results indicate: 1. Server-client IO is the major bottleneck, as Philip and you pointed out. 2. On the client side, the major bottlneck is the IO during textdelta application. David (CC'ed now) and I are trying some experiments with a single temporary file. Thoughts? > At least the results are much more useful when there is > a tool like Kcachegrind that allows easy navigation though > the huge amount of information that was gathered. Yep! The visualizer is quite awesome :) -- Ram
