From: Tay Ray Chuan Date: Sat, 18 Oct 2014 14:47:31 GMT Subject: Re: [PATCH] git-completion.bash - avoid excruciatingly slow ref completion on Cygwin Message-ID: In-Reply-To: <1413042673-24052-1-git-send-email-mlevedahl@gmail.com> On Sat, Oct 11, 2014 at 11:51 PM, Mark Levedahl wrote: > > $git checkout was taking about 3.5 seconds to respond on one > repository having four remotes with about 100 total refs (measured on > Cygwin). All of the time was being claimed in "git for-each-ref" to do > its work. This working directory was created using git-new-workdir, and > thus .git/refs and .git/packed-refs are both symlinks. for-each-ref > operates in a way that causes the .git/refs symlink to be resolved > multiple times for each ref in the repository, and Cygwin is especially > slow in such operations. Thanks for looking into this. > Patching refs.c to avoid repeatedly dereferencing the symlink reduced > execution time from about 3.5 seconds to about 1.1 seconds (but no > improvement on Linux), This makes your patch sound bad, but it isn't when one realises it is already fast on Linux! > [snip] > > Relevant timing results using the same repository on both Linux and > Cygwin: FWIW, timings on msysgit: $ time git for-each-ref --format="%(refname:short)" refs real 0m8.799s user 0m0.109s sys 0m0.250s $ time (cd "$GIT_DIR" ; cat packed-refs ; find refs/ -type f) \ 2>/dev/null | sed -ne 's@^.*refs/@refs/@p' | sort | uniq real 0m3.406s user 0m1.073s sys 0m2.398s so while your symlink-analysis might not accurately describe msysgit (I believe copies are made in place of a symlink), msysgit benefits from this too. -- Cheers, Ray Chuan -- -- *** Please reply-to-all at all times *** *** (do not pretend to know who is subscribed and who is not) *** *** Please avoid top-posting. *** The msysGit Wiki is here: https://github.com/msysgit/msysgit/wiki - Github accounts are free. You received this message because you are subscribed to the Google Groups "msysGit" group. To post to this group, send email to msysgit@googlegroups.com To unsubscribe from this group, send email to msysgit+unsubscribe@googlegroups.com For more options, and view previous threads, visit this group at http://groups.google.com/group/msysgit?hl=en_US?hl=en --- You received this message because you are subscribed to the Google Groups "Git for Windows" group. To unsubscribe from this group and stop receiving emails from it, send an email to msysgit+unsubscribe@googlegroups.com. For more options, visit https://groups.google.com/d/optout.