# Performance regression in git fetch between 1.8.3.4 and 1.8.5.3 3 messages from 2014-01-31 to 2014-02-01. Participants: brian m. carlson, Jeff King. Thread: https://gitlist.dev/t/35775 ## brian m. carlson, 2014-01-31 21:02 Subject: Performance regression in git fetch between 1.8.3.4 and 1.8.5.3 Message-ID: <20140131210154.GA632399@vauxhall.crustytoothpaste.net> URL: https://gitlist.dev/e/20140131210154.GA632399%40vauxhall.crustytoothpaste.net ``` At work, we recently upgraded our git version from 1.8.3.4 to 1.8.5.3. We've noticed a significant performance regression in git fetch. The numbers below are for an up-to-date branch (that is, no data is actually being fetched) for a git-over-ssh remote on our gitorious server. This is an auxiliary repository, so its size is probably between 6-7 GiB. It does not have an especially large number of refs, but is a clone of our main repository. Other than the new version, the only difference is that 1.8.5.3 is built against libpcre. These are both running on the same CentOS 6 system; literally the only difference is installing one RPM or the other. 1.8.3.4: brianc ok # for i in `seq 1 3`; do time git fetch; done git fetch 0.86s user 0.18s system 78% cpu 1.314 total git fetch 0.88s user 0.19s system 79% cpu 1.348 total git fetch 0.84s user 0.18s system 78% cpu 1.299 total 1.8.5.3: brianc ok # for i in `seq 1 3`; do time git fetch; done git fetch 17.11s user 1.22s system 98% cpu 18.652 total git fetch 16.74s user 1.24s system 98% cpu 18.286 total git fetch 17.78s user 1.35s system 98% cpu 19.446 total Does anyone have any idea what might be causing this? -- brian m. carlson / brian with sandals: Houston, Texas, US +1 832 623 2791 | http://www.crustytoothpaste.net/~bmc | My opinion only OpenPGP: RSA v4 4096b: 88AC E9B2 9196 305B A994 7552 F1BA 225C 0223 B187 ``` ## Jeff King, 2014-01-31 21:35 Subject: Re: Performance regression in git fetch between 1.8.3.4 and 1.8.5.3 Message-ID: <20140131213505.GA21264@sigill.intra.peff.net> URL: https://gitlist.dev/e/20140131213505.GA21264%40sigill.intra.peff.net In-Reply-To: <20140131210154.GA632399@vauxhall.crustytoothpaste.net> ``` On Fri, Jan 31, 2014 at 09:02:15PM +0000, brian m. carlson wrote: > At work, we recently upgraded our git version from 1.8.3.4 to 1.8.5.3. > We've noticed a significant performance regression in git fetch. The > numbers below are for an up-to-date branch (that is, no data is actually > being fetched) for a git-over-ssh remote on our gitorious server. Is it better with v1.9-rc1? There was a slowdown in v1.8.4.2 that I addressed with commit 200abe7 (which is slated for v1.9). -Peff ``` ## brian m. carlson, 2014-02-01 00:41 Subject: Re: Performance regression in git fetch between 1.8.3.4 and 1.8.5.3 Message-ID: <20140201004128.GA635004@vauxhall.crustytoothpaste.net> URL: https://gitlist.dev/e/20140201004128.GA635004%40vauxhall.crustytoothpaste.net In-Reply-To: <20140131213505.GA21264@sigill.intra.peff.net> ``` On Fri, Jan 31, 2014 at 04:35:05PM -0500, Jeff King wrote: > On Fri, Jan 31, 2014 at 09:02:15PM +0000, brian m. carlson wrote: > > > At work, we recently upgraded our git version from 1.8.3.4 to 1.8.5.3. > > We've noticed a significant performance regression in git fetch. The > > numbers below are for an up-to-date branch (that is, no data is actually > > being fetched) for a git-over-ssh remote on our gitorious server. > > Is it better with v1.9-rc1? There was a slowdown in v1.8.4.2 that I > addressed with commit 200abe7 (which is slated for v1.9). Yes. The time is much lower with 1.9-rc1: brianc ok # for i in `seq 1 3`; do time git fetch; done git fetch 0.90s user 0.18s system 74% cpu 1.447 total git fetch 0.88s user 0.20s system 74% cpu 1.456 total git fetch 0.88s user 0.19s system 74% cpu 1.438 total I'll open a case to get it updated once 1.9 is finally released. Thanks for your suggestion. -- brian m. carlson / brian with sandals: Houston, Texas, US +1 832 623 2791 | http://www.crustytoothpaste.net/~bmc | My opinion only OpenPGP: RSA v4 4096b: 88AC E9B2 9196 305B A994 7552 F1BA 225C 0223 B187 ```