strange git delays

strange git delays

[James Utter]

Hi,

Many git operations are running really slowly for me.
For example 'git commit' and 'git branch' are taking 10 seconds to
complete, even on an almost empty repository, and no longer on a 60MB
repository with plenty of history.

There does not appear to be any CPU or disk activity caused by git.

I would appreciate your help in resolving this problem.

Regards,

James Utter


Details of my environment:
-------------------------------
Linux 2.6.24-1-amd64 #1 SMP x86_64 (from debian testing) [1]
git-core 1:1.5.4.3-1 (from debian testing) [2]
Core 2 duo, 2Ghz

[1] I have been experiencing this problem across several kernels
[2] possibly over several git versions too (not sure)

Here is a test run on my computer
---------------------------------
james@timesink:~$ mkdir testgit
james@timesink:~$ cd testgit/
james@timesink:~/testgit$ time git init-db
Initialized empty Git repository in .git/

real	0m0.013s
user	0m0.000s
sys	0m0.008s
james@timesink:~/testgit$ echo "hai there" > hello
james@timesink:~/testgit$ time git add .

real	0m0.103s
user	0m0.000s
sys	0m0.004s
james@timesink:~/testgit$ time git commit --message "initial commit"
Created initial commit 4f4b3a3: initial commit
 1 files changed, 1 insertions(+), 0 deletions(-)
 create mode 100644 hello

real	0m10.008s
user	0m0.000s
sys	0m0.008s
james@timesink:~/testgit$ time git branch new

real	0m10.006s
user	0m0.000s
sys	0m0.004s
james@timesink:~/testgit$ time git branch -d new
Deleted branch new.

real	0m0.005s
user	0m0.000s
sys	0m0.004s
james@timesink:~/testgit$ echo "im in ur git\n slowin ur workflo" >>
hello
james@timesink:~/testgit$ time git commit -a --message "how long"
Created commit 2392de6: how long
 1 files changed, 1 insertions(+), 0 deletions(-)

real	0m10.059s
user	0m0.000s
sys	0m0.008s

Re: strange git delays

[Johannes Sixt]

James Utter schrieb:
> Many git operations are running really slowly for me.
> For example 'git commit' and 'git branch' are taking 10 seconds to
> complete, even on an almost empty repository, and no longer on a 60MB
> repository with plenty of history.
> 
> There does not appear to be any CPU or disk activity caused by git.

...

> james@timesink:~/testgit$ time git commit --message "initial commit"
> Created initial commit 4f4b3a3: initial commit
>  1 files changed, 1 insertions(+), 0 deletions(-)
>  create mode 100644 hello
> 
> real	0m10.008s
> user	0m0.000s
> sys	0m0.008s

What does

  strace -c git commit --message "initial commit"

report? 'strace -tt' or 'strace -T'?

-- Hannes

Re: strange git delays

[Johannes Schindelin]

Hi,

On Fri, 21 Mar 2008, James Utter wrote:

> james@timesink:~/testgit$ time git commit --message "initial commit"
> Created initial commit 4f4b3a3: initial commit
>  1 files changed, 1 insertions(+), 0 deletions(-)
>  create mode 100644 hello
> 
> real	0m10.008s
> user	0m0.000s
> sys	0m0.008s

I'd try to oprofile it to know what is taking so long.

Hth,
Dscho

Re: strange git delays

[Linus Torvalds]

On Fri, 21 Mar 2008, James Utter wrote:
>
> james@timesink:~/testgit$ time git commit --message "initial commit"
> Created initial commit 4f4b3a3: initial commit
>  1 files changed, 1 insertions(+), 0 deletions(-)
>  create mode 100644 hello
> 
> real	0m10.008s
> user	0m0.000s
> sys	0m0.008s

Ok, that is almost exactly 10 seconds longer than it should take.

And I can almost guarantee that it's something like a problem looking up 
your hostname or perhaps user identity - I would guess you have some name 
service problem.

Do an

	strace -tT git commit --message "initial commit"

on that git commit to make sure, but I would almost bet that it's when git 
does tget "getpwuid()" thing to get your name from the gecos fields, and 
you have some setup problem with nscd o similar.

It might just go away if you set up your user name and email manually, ie 
try doing

	git config --global user.name "James Utter"
	git config --global user.email james.utter@gmail.com

and see if that makes the delay go away. It probably tries to look up your 
login info from some non-existent NIS setup, and then times out after ten 
seconds and picks the data from your /etc/passwd file instead.

(There can be other things that do similar things - misconfigured name 
servers etc can cause delay etc. So maybe I'm wrogn on blaming nscd, but 
it would be my first guess).

		Linus