{"thread":{"id":"35775","subject":"Performance regression in git fetch between 1.8.3.4 and 1.8.5.3","startedAt":"2014-01-31T21:02:15Z","lastAt":"2014-02-01T00:41:28Z","messageCount":3,"participants":["brian m. carlson","Jeff King"],"isPatch":false,"patchVersion":null,"patchTotal":null},"messages":[{"id":"233996","messageId":"20140131210154.GA632399@vauxhall.crustytoothpaste.net","threadId":"35775","inReplyTo":null,"subject":"Performance regression in git fetch between 1.8.3.4 and 1.8.5.3","fromName":"brian m. carlson","fromEmail":"sandals@crustytoothpaste.net","sentAt":"2014-01-31T21:02:15Z","receivedAt":"2014-01-31T21:02:15Z","isPatch":false,"sender":{"key":"sandals@crustytoothpaste.net","avatar":"https://avatars.githubusercontent.com/u/497054?v=4"},"body":"At work, we recently upgraded our git version from 1.8.3.4 to 1.8.5.3.\nWe've noticed a significant performance regression in git fetch.  The\nnumbers below are for an up-to-date branch (that is, no data is actually\nbeing fetched) for a git-over-ssh remote on our gitorious server.\n\nThis is an auxiliary repository, so its size is probably between 6-7\nGiB.  It does not have an especially large number of refs, but is a\nclone of our main repository.\n\nOther than the new version, the only difference is that 1.8.5.3 is built\nagainst libpcre.  These are both running on the same CentOS 6 system;\nliterally the only difference is installing one RPM or the other.\n\n1.8.3.4:\n\n  brianc ok # for i in `seq 1 3`; do time git fetch; done\n  git fetch  0.86s user 0.18s system 78% cpu 1.314 total\n  git fetch  0.88s user 0.19s system 79% cpu 1.348 total\n  git fetch  0.84s user 0.18s system 78% cpu 1.299 total\n\n1.8.5.3:\n\n  brianc ok # for i in `seq 1 3`; do time git fetch; done\n  git fetch  17.11s user 1.22s system 98% cpu 18.652 total\n  git fetch  16.74s user 1.24s system 98% cpu 18.286 total\n  git fetch  17.78s user 1.35s system 98% cpu 19.446 total\n\nDoes anyone have any idea what might be causing this?\n\n-- \nbrian m. carlson / brian with sandals: Houston, Texas, US\n+1 832 623 2791 | http://www.crustytoothpaste.net/~bmc | My opinion only\nOpenPGP: RSA v4 4096b: 88AC E9B2 9196 305B A994 7552 F1BA 225C 0223 B187\n"},{"id":"233998","messageId":"20140131213505.GA21264@sigill.intra.peff.net","threadId":"35775","inReplyTo":"20140131210154.GA632399@vauxhall.crustytoothpaste.net","subject":"Re: Performance regression in git fetch between 1.8.3.4 and 1.8.5.3","fromName":"Jeff King","fromEmail":"peff@peff.net","sentAt":"2014-01-31T21:35:05Z","receivedAt":"2014-01-31T21:35:05Z","isPatch":false,"sender":{"key":"peff@peff.net","avatar":"https://avatars.githubusercontent.com/u/45925?v=4"},"body":"On Fri, Jan 31, 2014 at 09:02:15PM +0000, brian m. carlson wrote:\n\n> At work, we recently upgraded our git version from 1.8.3.4 to 1.8.5.3.\n> We've noticed a significant performance regression in git fetch.  The\n> numbers below are for an up-to-date branch (that is, no data is actually\n> being fetched) for a git-over-ssh remote on our gitorious server.\n\nIs it better with v1.9-rc1? There was a slowdown in v1.8.4.2 that I\naddressed with commit 200abe7 (which is slated for v1.9).\n\n-Peff\n"},{"id":"234003","messageId":"20140201004128.GA635004@vauxhall.crustytoothpaste.net","threadId":"35775","inReplyTo":"20140131213505.GA21264@sigill.intra.peff.net","subject":"Re: Performance regression in git fetch between 1.8.3.4 and 1.8.5.3","fromName":"brian m. carlson","fromEmail":"sandals@crustytoothpaste.net","sentAt":"2014-02-01T00:41:28Z","receivedAt":"2014-02-01T00:41:28Z","isPatch":false,"sender":{"key":"sandals@crustytoothpaste.net","avatar":"https://avatars.githubusercontent.com/u/497054?v=4"},"body":"On Fri, Jan 31, 2014 at 04:35:05PM -0500, Jeff King wrote:\n> On Fri, Jan 31, 2014 at 09:02:15PM +0000, brian m. carlson wrote:\n> \n> > At work, we recently upgraded our git version from 1.8.3.4 to 1.8.5.3.\n> > We've noticed a significant performance regression in git fetch.  The\n> > numbers below are for an up-to-date branch (that is, no data is actually\n> > being fetched) for a git-over-ssh remote on our gitorious server.\n> \n> Is it better with v1.9-rc1? There was a slowdown in v1.8.4.2 that I\n> addressed with commit 200abe7 (which is slated for v1.9).\n\nYes.  The time is much lower with 1.9-rc1:\n\n  brianc ok # for i in `seq 1 3`; do time git fetch; done\n  git fetch  0.90s user 0.18s system 74% cpu 1.447 total\n  git fetch  0.88s user 0.20s system 74% cpu 1.456 total\n  git fetch  0.88s user 0.19s system 74% cpu 1.438 total\n\nI'll open a case to get it updated once 1.9 is finally released.  Thanks\nfor your suggestion.\n\n-- \nbrian m. carlson / brian with sandals: Houston, Texas, US\n+1 832 623 2791 | http://www.crustytoothpaste.net/~bmc | My opinion only\nOpenPGP: RSA v4 4096b: 88AC E9B2 9196 305B A994 7552 F1BA 225C 0223 B187\n"}]}