Extremely slow start up with ruby 1.9.1 vs 1.8.7

Rails
21

Count me in :confused:

On ubuntu 10.10 with ruby 1.9.2 and a fresh rails 3.0.3. I created a
cucumber feature with one scenario.

Running cucumber takes about 18 seconds, with 17 seconds spent doing
calls to kernel#require.

See: https://gist.github.com/780747

Now, I installed ruby from ubuntu repos/ppa, which I am not sure it
provided the latest ruby. So I removed everything and installed rvm.
Installed ruby 1.9.2-p136 and had same issue. Then installed ree 1.8.7,
and did not have the issue. It’s much faster. I will watch closely the
-core mailing list for a possible resolution, but for now, I will use
ree.

See: Using rvm this time, with ree · GitHub

22

This issue in 1.9.2 was affecting me enough that I switched back to
1.8.7, but not without doing a bit of research in to what the problem
was.

We see a performance loss in 1.9.2 as it exhibits the correct behaviour
when calling require, whereas 1.8.7 is reliant on incorrect semantics
that are not acceptable for production use. I was never affected by
these incorrect semantics, but I suppose ruby-core has to right these
things or accept the long term technical debt.

Something called gem_prelude was added to ruby 1.9 as kludge to address
some performance issues.

Ryan David explain (from the ruby-core list):

It (gem_prelude) was created to address a symptom, namely, that rubygems was
slow on some systems (and proportional to the number of gems you have installed).

The good news is: a patch was committed (Jan 14) to ruby that should
address some of the performance issues we’re seeing. Namely, 1.9.2 users
will be able to upgrade to rubygems 1.4 which offers some improved
performance.

I don’t know when we’ll see the next ruby release, but I’m encouraged to
see some progress. I’m also encouraged to see that there are members of
the ruby-core team actively investigating and addressing these issues.

Luke

23

Hi, in order to put your numbers below into context, can you post the
spec for your hardware?

Thanks,

-Conrad

Sent from my iPhone

24

Jp Jphpsf wrote in post #975316:

Also, with rvm, I think I can install ruby from head, see if it improves
the performance problem.

I’ve installed ruby-head via rvm, and updated my gist. It does seem to
be an improvement! Still lagging behind ree, though.

25

Conrad T. wrote in post #975240:

Hi, in order to put your numbers below into context, can you post the
spec for your hardware?

Thanks,

-Conrad

I was running the test on my laptop (core 2 duo 1.86ghz + 2gb ram +
5400rpm hdd). I might run the same test on my desktop (quad core 3.2 ghz

  • 4gb + 10000 rpm drive).

Also, with rvm, I think I can install ruby from head, see if it improves
the performance problem.

26

Using ruby-prof I captured the CPU time of the startup of my 3.0.3
Rails app (https://gist.github.com/762764):

…

ruby-1.9.2-p136 (Total CPU 16.794391)

%self total self wait child calls name
39.93 16.47 6.71 0.00 16.46 1904 Kernel#require
3.85 2.51 0.65 0.00 2.23 14252 Array#map

If require is your bottleneck, you can use the faster_require gem:

-r