On 12/6/07, Nicolas Pitre <nico@xxxxxxx> wrote: > > When I lasted looked at the code, the problem was in evenly dividing > > the work. I was using a four core machine and most of the time one > > core would end up with 3-5x the work of the lightest loaded core. > > Setting pack.threads up to 20 fixed the problem. With a high number of > > threads I was able to get a 4hr pack to finished in something like > > 1:15. > > But as far as I know you didn't try my latest incarnation which has been > available in Git's master branch for a few months already. I've deleted all my giant packs. Using the kernel pack: 4GB Q6600 Using the current thread pack code I get these results. The interesting case is the last one. I set it to 15 threads and monitored with 'top'. For 0-60% compression I was at 300% CPU, 60-74% was 200% CPU and 74-100% was 100% CPU. It never used all for cores. The only other things running were top and my desktop. This is the same load balancing problem I observed earlier. Much more clock time was spent in the 2/1 core phases than the 3 core one. Threaded, threads = 5 jonsmirl@terra:/home/linux$ time git repack -a -d -f Counting objects: 648366, done. Compressing objects: 100% (647457/647457), done. Writing objects: 100% (648366/648366), done. Total 648366 (delta 528994), reused 0 (delta 0) real 1m31.395s user 2m59.239s sys 0m3.048s jonsmirl@terra:/home/linux$ 12 seconds counting 53 seconds compressing 38 seconds writing Without threads, jonsmirl@terra:/home/linux$ time git repack -a -d -f warning: no threads support, ignoring pack.threads Counting objects: 648366, done. Compressing objects: 100% (647457/647457), done. Writing objects: 100% (648366/648366), done. Total 648366 (delta 528999), reused 0 (delta 0) real 2m54.849s user 2m51.267s sys 0m1.412s jonsmirl@terra:/home/linux$ Threaded, threads = 5 jonsmirl@terra:/home/linux$ time git repack -a -d -f --depth=250 --window=250 Counting objects: 648366, done. Compressing objects: 100% (647457/647457), done. Writing objects: 100% (648366/648366), done. Total 648366 (delta 539080), reused 0 (delta 0) real 9m18.032s user 19m7.484s sys 0m3.880s jonsmirl@terra:/home/linux$ jonsmirl@terra:/home/linux/.git/objects/pack$ ls -l total 182156 -r--r--r-- 1 jonsmirl jonsmirl 15561848 2007-12-06 16:15 pack-f1f8637d2c68eb1c964ec7c1877196c0c7513412.idx -r--r--r-- 1 jonsmirl jonsmirl 170768761 2007-12-06 16:15 pack-f1f8637d2c68eb1c964ec7c1877196c0c7513412.pack jonsmirl@terra:/home/linux/.git/objects/pack$ Non-threaded: jonsmirl@terra:/home/linux$ time git repack -a -d -f --depth=250 --window=250 warning: no threads support, ignoring pack.threads Counting objects: 648366, done. Compressing objects: 100% (647457/647457), done. Writing objects: 100% (648366/648366), done. Total 648366 (delta 539080), reused 0 (delta 0) real 18m51.183s user 18m46.538s sys 0m1.604s jonsmirl@terra:/home/linux$ jonsmirl@terra:/home/linux/.git/objects/pack$ ls -l total 182156 -r--r--r-- 1 jonsmirl jonsmirl 15561848 2007-12-06 15:33 pack-f1f8637d2c68eb1c964ec7c1877196c0c7513412.idx -r--r--r-- 1 jonsmirl jonsmirl 170768761 2007-12-06 15:33 pack-f1f8637d2c68eb1c964ec7c1877196c0c7513412.pack jonsmirl@terra:/home/linux/.git/objects/pack$ Threaded, threads = 15 jonsmirl@terra:/home/linux$ time git repack -a -d -f --depth=250 --window=250 Counting objects: 648366, done. Compressing objects: 100% (647457/647457), done. Writing objects: 100% (648366/648366), done. Total 648366 (delta 539080), reused 0 (delta 0) real 9m18.325s user 19m14.340s sys 0m3.996s jonsmirl@terra:/home/linux$ -- Jon Smirl jonsmirl@xxxxxxxxx - To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
