MemoryProfiler
A memory profiler for Ruby
Requirements
Ruby(MRI) Version 2.3.8 and above.
Installation
Add this line to your application's Gemfile:
gem 'memory_profiler'
And then execute:
$ bundle
Or install it yourself as:
$ gem install memory_profiler
Usage
There are two ways to use memory_profiler
:
- command line
- convenience API
Command Line
The easiest way to use memory_profiler is via the command line, which requires no modifications to your program. The basic usage is:
$ ruby-memory-profiler [options] <script.rb> [--] [script-options]
Where script.rb
is the program you want to profile.
For a full list of options, execute the following command:
ruby-memory-profiler -h
Convenience API
require 'memory_profiler'
report = MemoryProfiler.report do
# run your code here
end
report.pretty_print
Or, you can use the .start
/.stop
API as well:
require 'memory_profiler'
MemoryProfiler.start
# run your code
report = MemoryProfiler.stop
report.pretty_print
NOTE: .start
/.stop
can only be run once per report, and .stop
will
be the only time you can retrieve the report using this API.
Options
report
The report
method can take a few options:
top
: maximum number of entries to display in a report (default is 50)allow_files
: include only certain files from tracing - can be given as a String, Regexp, or array of Stringsignore_files
: exclude certain files from tracing - can be given as a String or Regexptrace
: an array of classes for which you explicitly want to trace object allocations
Check out Reporter#new
for more details.
pry> require 'memory_profiler'
pry> MemoryProfiler.report(allow_files: 'rubygems'){ require 'mime-types' }.pretty_print
Total allocated 82375
Total retained 22618
allocated memory by gem
-----------------------------------
rubygems x 305879
allocated memory by file
-----------------------------------
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb x 285433
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/basic_specification.rb x 18597
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems.rb x 2218
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/specification.rb x 1169
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/defaults.rb x 520
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/core_ext/kernel_gem.rb x 80
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/version.rb x 80
. . .
pretty_print
The pretty_print
method can take a few options:
to_file
: a path to your log file - can be given a Stringcolor_output
: a flag for whether to colorize output - can be given a Booleanretained_strings
: how many retained strings to print - can be given an Integerallocated_strings
: how many allocated strings to print - can be given a Stringdetailed_report
: should report include detailed information - can be given a Booleanscale_bytes
: flag to convert byte units (e.g. 183200000 is reported as 183.2 MB, rounds with a precision of 2 decimal digits) - can be given a Booleannormalize_paths
: flag to remove a gem's directory path from printed locations - can be given a Boolean Note: normalized path of a "location" from Ruby's stdlib will be prefixed withruby/lib/
. e.g.:ruby/lib/set.rb
,ruby/lib/pathname.rb
, etc.
Check out Results#pretty_print
for more details.
For example to report to file, use pretty_print
method with to_file
option and path_to_your_log_file
string:
$ pry
pry> require 'memory_profiler'
pry> MemoryProfiler.report(allow_files: 'rubygems'){ require 'mime-types' }.pretty_print(to_file: 'path_to_your_log_file')
$ less my_report.txt
Total allocated 82375
Total retained 22618
allocated memory by gem
-----------------------------------
rubygems x 305879
. . .
Example Session
You can easily use memory_profiler to profile require impact of a gem, for example:
pry> require 'memory_profiler'
pry> MemoryProfiler.report{ require 'mime-types' }.pretty_print
Total allocated 82375
Total retained 22618
allocated memory by gem
-----------------------------------
mime-types-2.0 x 3668277
2.1.0-github/lib x 2035704
rubygems x 305879
other x 40
allocated memory by file
-----------------------------------
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb x 3391763
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/json/common.rb x 2021853
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb x 285433
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/types/loader.rb x 227033
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/types/cache.rb x 48663
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/basic_specification.rb x 18597
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/x86_64-linux/json/ext/parser.so x 8200
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/x86_64-linux/json/ext/generator.so x 2463
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems.rb x 2218
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/specification.rb x 1169
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/defaults.rb x 520
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/types/loader_path.rb x 417
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/json/version.rb x 409
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/types.rb x 361
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/json/generic_object.rb x 241
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/json/ext.rb x 200
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/json.rb x 120
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/core_ext/kernel_gem.rb x 80
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/version.rb x 80
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime-types.rb x 40
(pry) x 40
allocated memory by location
-----------------------------------
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/json/common.rb:155 x 1985709
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:522 x 927503
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:632 x 827676
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:302 x 499525
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:625 x 281047
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:521 x 265920
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:629 x 265920
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:523 x 265920
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:55 x 222705
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/types/loader.rb:215 x 218105
[REDACTED]
allocated]objects by gem
-----------------------------------
mime-types-2.0 x 56564
2.1.0-github/lib x 22210
rubygems x 3600
other x 1
allocated objects by file
-----------------------------------
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb x 56237
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/json/common.rb x 21978
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb x 3388
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/types/cache.rb x 291
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/basic_specification.rb x 169
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/x86_64-linux/json/ext/parser.so x 124
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems.rb x 53
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/x86_64-linux/json/ext/generator.so x 37
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/specification.rb x 26
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/types/loader.rb x 24
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/defaults.rb x 13
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/json/version.rb x 7
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/types.rb x 6
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/types/loader_path.rb x 5
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/json/ext.rb x 5
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/json.rb x 3
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/json/generic_object.rb x 3
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/core_ext/kernel_gem.rb x 2
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/version.rb x 2
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime-types.rb x 1
(pry) x 1
allocated objects by location
-----------------------------------
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:522 x 21337
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/json/common.rb:155 x 21095
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:632 x 9972
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:523 x 6648
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:521 x 6648
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:629 x 6648
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:55 x 3307
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:302 x 2955
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:625 x 1663
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/json/common.rb:60 x 837
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:224 x 312
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/types/cache.rb:62 x 287
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/x86_64-linux/json/ext/parser.so:0 x 124
[REDACTED]
retained memory by gem
-----------------------------------
mime-types-2.0 x 1496813
2.1.0-github/lib x 519954
rubygems x 76195
retained memory by file
-----------------------------------
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb x 1447316
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/json/common.rb x 516679
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb x 75946
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/types/cache.rb x 48583
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/x86_64-linux/json/ext/generator.so x 2263
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/x86_64-linux/json/ext/parser.so x 892
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/types/loader.rb x 577
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/types/loader_path.rb x 297
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/basic_specification.rb x 169
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/specification.rb x 80
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/types.rb x 40
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/json/generic_object.rb x 40
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/json/ext.rb x 40
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/json/version.rb x 40
retained memory by location
-----------------------------------
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/json/common.rb:155 x 516181
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:302 x 499525
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:632 x 414007
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:625 x 280878
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:629 x 132960
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:523 x 66480
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:135 x 58151
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:224 x 52728
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/types/cache.rb:62 x 48503
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:55 x 17795
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/x86_64-linux/json/ext/generator.so:0 x 2263
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/x86_64-linux/json/ext/parser.so:0 x 892
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/types/loader.rb:239 x 577
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/types/loader_path.rb:15 x 257
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/basic_specification.rb:124 x 169
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/json/common.rb:122 x 89
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:46 x 89
[REDUCTED]
retained objects by gem
-----------------------------------
mime-types-2.0 x 15211
2.1.0-github/lib x 7089
rubygems x 318
retained objects by file
-----------------------------------
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb x 14918
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/json/common.rb x 7045
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb x 315
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/types/cache.rb x 289
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/x86_64-linux/json/ext/generator.so x 32
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/x86_64-linux/json/ext/parser.so x 9
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/specification.rb x 2
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/types/loader_path.rb x 2
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/types/loader.rb x 1
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/types.rb x 1
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/json/version.rb x 1
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/json/generic_object.rb x 1
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/json/ext.rb x 1
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/basic_specification.rb x 1
retained objects by location
-----------------------------------
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/json/common.rb:155 x 7035
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:632 x 4987
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:629 x 3324
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:302 x 2955
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:625 x 1662
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:523 x 1662
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:224 x 312
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:55 x 300
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/types/cache.rb:62 x 287
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/x86_64-linux/json/ext/generator.so:0 x 32
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:135 x 15
[REDUCTED]
Allocated String Report
-----------------------------------
"application" x 12050
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:522 x 4820
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:521 x 2410
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:632 x 2410
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:629 x 2410
"" x 6669
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:522 x 6648
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:55 x 11
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:266 x 4
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/json/common.rb:71 x 1
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/json/common.rb:72 x 1
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/json/common.rb:69 x 1
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:0 x 1
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/core_ext/kernel_gem.rb:39 x 1
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/json/common.rb:70 x 1
"/" x 3342
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:523 x 3324
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:55 x 13
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/json/common.rb:60 x 4
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:135 x 1
"encoding" x 3336
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/json/common.rb:155 x 3324
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:55 x 10
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:135 x 1
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/json/common.rb:60 x 1
"registered" x 3328
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/json/common.rb:155 x 3324
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:55 x 4
"content-type" x 3327
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/json/common.rb:155 x 3324
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:55 x 3
"references" x 2944
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/json/common.rb:155 x 2940
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:55 x 4
"IANA" x 2824
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/json/common.rb:155 x 1412
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:302 x 1412
[REDUCTED]
Retained String Report
-----------------------------------
"IANA" x 2824
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/json/common.rb:155 x 1412
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:302 x 1412
"application" x 2410
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:632 x 1205
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:629 x 1205
"base64" x 1527
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/json/common.rb:155 x 1525
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:70 x 1
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:55 x 1
"audio" x 300
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:632 x 150
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:629 x 150
"video" x 188
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:632 x 94
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:629 x 94
"text" x 155
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:629 x 77
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/gems/2.1.0/gems/mime-types-2.0/lib/mime/type.rb:632 x 77
/home/sam/.rbenv/versions/2.1.0-github/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:55 x 1
[REDUCTED]
The data is also available in the MemoryProfiler::Results object returned.
Retained vs Allocated
The report breaks down 2 key concepts.
Retained: long lived memory use and object count retained due to the execution of the code block.
Allocated: All object allocation and memory allocation during code block.
As a general rule "retained" will always be smaller than or equal to allocated.
Memory profiler will tell you aggregate costs of the above, for example requiring the mime-types gem above results in approx 2MB of retained memory in 22K or so objects. The actual RSS cost will always be slightly higher as MRI heaps are not squashed to size and memory fragments. In future we may be able to calculate a rough long term GC cost of retained objects (for major GCs).
Memory profiler also performs some String analysis to help you find strings that would heavily benefit from #freeze. In the example above the string IANA is retained in memory 2824 times, this costs you a minimum of RVALUE_SIZE (40 on x64) * 2824.
Contributing
- Fork it
- Create your feature branch (
git checkout -b my-new-feature
) - Commit your changes (
git commit -am 'Add some feature'
) - Push to the branch (
git push origin my-new-feature
) - Create new Pull Request