=== yofel_ is now known as yofel [21:52] which algorithm does bzr use to compress .pack files? [21:57] is it gzip/bzip2 or something? [21:58] does it spawn an external process to decompress or it uses a C module from within the same process? [21:59] it bogs down my CPU and I must find out why... [22:04] it's zlib, in process [22:04] compression just takes work, there aren't magic fixes [22:05] hmmm so I guess it could be related [22:05] wgz: there are fixes, not magic ofcourse [22:06] wgz: the .pack files I assume the contain many small compressed chunks. About how large is each? [22:06] I'm asking because I notice too much seeking too [22:07] I've already filed a bug report, I'm just looking a bit more into it [22:07] right, most of the obvious issues are much higher level than the comprssion step [22:08] probably true, but if it reads through the *whole* pack files then it would take some time to decompress .5GB [22:09] ? [22:09] there's an index file next to it [22:09] bob2: saw it, but still when stracing it I see too many reads, I think it's seeking through most of the file... [22:10] I should measure exactly how much it reads from disk [22:10] decompressing an entire pack when only part of it needed may be a bug, that decompressing a big chunk of data takes cpu isn't :) [22:10] wgz: that's why I was asking about the comression [22:11] first, if it was spawning separate gzip processes then it would use a second core [22:11] except that if the decompression is the bottleneck like oyu say, that's of no use [22:11] second, there are faster algorithms from gzip, with other tradeoffs of cource [22:11] have you read the pack format docs? [22:11] true have to find out how much it reads :-p [22:12] I'd suggest that's the wrong end to tackle things from [22:12] +1 [22:12] bob2: only a generic doc is what I found [22:12] no idea what that means [22:12] pointer to the pack docs? [22:13] for something like bug 1006194 I'd start by seeing if it's opening the repo twice [22:13] Launchpad bug 1006194 in Bazaar "bzr diff too slow (cpu intensive) on large projects" [Undecided,New] https://launchpad.net/bugs/1006194 [22:13] rather than assuming zlib can be improved on or trying to launch multiple workers [22:13] wgz: how can I see it? [22:14] and why would it be opening it twice? [22:14] bob2: http://doc.bazaar.canonical.com/latest/developers/packrepo.html is the doc I found [22:15] because the bug states that it's an issue when there are two different branches are involved [22:15] but didn't mention anything about compression algorithm [22:16] wgz: even with same branch but -r-2 overhead is the same [22:16] also see the mailing list archives about log performance [22:17] latest quarter? [22:20] jimis: eg. [22:22] thanks wgz, seems relevant [22:27] Even though these points may apply, bzr log -r-2 is instantaneous in my case.