Lazy evaluating asset timestamps on sprockets on 3.6.0 https://github.com/rails/sprockets/pull/211

lazy_timestamping_assets.log

# Using sprockets 3.6.0 with spocket-rails 3.0.4

# 171 - 177 MB of memory used booting rails before
11:24:33 ~/Code/manageiq (master) (2.2.5) + RAILS_ENV=production bin/rails r 'top = `/usr/bin/top -l 1 -pid #{Process.pid} | grep -E "ruby.+M"`; memory = top.split[7].to_i; puts memory'
177
11:24:43 ~/Code/manageiq (master) (2.2.5) + RAILS_ENV=production bin/rails r 'top = `/usr/bin/top -l 1 -pid #{Process.pid} | grep -E "ruby.+M"`; memory = top.split[7].to_i; puts memory'
171
11:25:31 ~/Code/manageiq (master) (2.2.5) + RAILS_ENV=production bin/rails r 'top = `/usr/bin/top -l 1 -pid #{Process.pid} | grep -E "ruby.+M"`; memory = top.split[7].to_i; puts memory'
177

# 8.3 seconds booting rails before
11:25:51 ~/Code/manageiq (master) (2.2.5) + time RAILS_ENV=production bin/rails r 1
RAILS_ENV=production bin/rails r 1  6.81s user 1.41s system 99% cpu 8.256 total
11:26:15 ~/Code/manageiq (master) (2.2.5) + time RAILS_ENV=production bin/rails r 1
RAILS_ENV=production bin/rails r 1  6.88s user 1.40s system 99% cpu 8.320 total
11:26:25 ~/Code/manageiq (master) (2.2.5) + time RAILS_ENV=production bin/rails r 1
RAILS_ENV=production bin/rails r 1  6.85s user 1.43s system 99% cpu 8.319 total

# Now, patch sprockets 3.6.0
11:26:39 ~/Code/manageiq (master) (2.2.5) + bundle show sprockets
/Users/joerafaniello/.gem/ruby/2.2.5/gems/sprockets-3.6.0
11:26:52 ~/Code/manageiq (master) (2.2.5) + pushd /Users/joerafaniello/.gem/ruby/2.2.5/gems/sprockets-3.6.0
11:27:01 ~GEM_HOME/gems/sprockets-3.6.0 (2.2.5) + wget https://github.com/rails/sprockets/commit/d0698b3c338ab3372d00e5b8d0cb5f496742e1f7.patch
--2016-06-02 11:27:02--  https://github.com/rails/sprockets/commit/d0698b3c338ab3372d00e5b8d0cb5f496742e1f7.patch
Resolving github.com... 192.30.252.130
Connecting to github.com|192.30.252.130|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: unspecified [text/plain]
Saving to: 'd0698b3c338ab3372d00e5b8d0cb5f496742e1f7.patch'

d0698b3c338ab3372d00e5b8d0cb5f496742e1f7.patch      [ <=>                                                                                                   ]   1.74K  --.-KB/s   in 0.002s

2016-06-02 11:27:02 (1.13 MB/s) - 'd0698b3c338ab3372d00e5b8d0cb5f496742e1f7.patch' saved [1780]

11:27:17 ~GEM_HOME/gems/sprockets-3.6.0 (2.2.5) + patch -p1 < d0698b3c338ab3372d00e5b8d0cb5f496742e1f7.patch
patching file lib/sprockets/cache/file_store.rb


11:27:22 ~GEM_HOME/gems/sprockets-3.6.0 (2.2.5) + popd

# 163-165 MB of memory used booting rails After( ~10 MB saved )
11:27:28 ~/Code/manageiq (master) (2.2.5) + RAILS_ENV=production bin/rails r 'top = `/usr/bin/top -l 1 -pid #{Process.pid} | grep -E "ruby.+M"`; memory = top.split[7].to_i; puts memory'
163
11:27:37 ~/Code/manageiq (master) (2.2.5) + RAILS_ENV=production bin/rails r 'top = `/usr/bin/top -l 1 -pid #{Process.pid} | grep -E "ruby.+M"`; memory = top.split[7].to_i; puts memory'
165
11:27:47 ~/Code/manageiq (master) (2.2.5) + RAILS_ENV=production bin/rails r 'top = `/usr/bin/top -l 1 -pid #{Process.pid} | grep -E "ruby.+M"`; memory = top.split[7].to_i; puts memory'
163

# 8 seconds booting rails after (~0.3 seconds saved)
11:28:00 ~/Code/manageiq (master) (2.2.5) + time RAILS_ENV=production bin/rails r 1
RAILS_ENV=production bin/rails r 1  6.66s user 1.29s system 99% cpu 7.984 total
11:28:10 ~/Code/manageiq (master) (2.2.5) + time RAILS_ENV=production bin/rails r 1
RAILS_ENV=production bin/rails r 1  6.75s user 1.29s system 99% cpu 8.073 total
11:28:29 ~/Code/manageiq (master) (2.2.5) + time RAILS_ENV=production bin/rails r 1
RAILS_ENV=production bin/rails r 1  6.73s user 1.29s system 99% cpu 8.053 total