Re: git checkout running very slowly (>12s)

Andrew Cameron <andrew <at> worksmartlabs.com> writes:

In the interest of leaving a message of hope in the archives for users experiencing this same problem, I will record to the list that I managed to solve the problem, if not understand it. As you can see in the transcript above, I had been using an older version of git:

After running sudo apt-get build-dep git-core and then building git from source, we see this instead:

And the success story:

$ time git checkout master Switched to branch 'master' git checkout master 0.88s user 0.25s system 99% cpu 1.135 total $ time git checkout - Switched to branch 'newbranch' git checkout - 0.87s user 0.25s system 99% cpu 1.121 total

It might be interesting to note that both before and after upgrading git, running "strace -c git checkout master" in an attempt to figure out where all my time was spent was *not* particularly helpful. An excerpt from strace's output from before the upgrade:

% time seconds usecs/call calls errors syscall ------ ----------- ----------- --------- --------- ---------------- 100.00 0.003499 0 90884 7 lstat64

And another one from afterwards:

% time     seconds  usecs/call     calls    errors syscall
------ ----------- ----------- --------- --------- ----------------
 99.24    0.003276           0     90886         7 lstat64

In other words, it appears that an efficient lstat implementation was not the key factor in this problem. The root cause remains a mystery, but in my case, the solution was to upgrade Git.

Thanks for reading.