# Difficulty in understanding the valgrind output for ror app **URL:** \ **Category:** Rails\ **Created:** [November 5, 2008, 7:09am UTC](https://www.ruby-forum.com/t/difficulty-in-understanding-the-valgrind-output-for-ror-app/152563 "2008-11-05T07:09:26Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![santoshturamari](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/ee59a6/32.png) [@santoshturamari](https://www.ruby-forum.com/u/santoshturamari)\ **Post date:** [November 5, 2008, 7:09am UTC](https://www.ruby-forum.com/t/difficulty-in-understanding-the-valgrind-output-for-ror-app/152563/1 "2008-11-05T07:09:26Z")
Hi, I am facing the difficulty in understanding the output of valgrind memory leaks. How to interpret it. pls help me out. ---
**Author:** ![santoshturamari](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/ee59a6/32.png) [@santoshturamari](https://www.ruby-forum.com/u/santoshturamari)\ **Post date:** [November 5, 2008, 3:38pm UTC](https://www.ruby-forum.com/t/difficulty-in-understanding-the-valgrind-output-for-ror-app/152563/2 "2008-11-05T15:38:55Z")
On Nov 5, 1:09 am, Santosh T. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Hi, > I am facing the difficulty in understanding the output of valgrind > memory leaks. How to interpret it. pls help me out. For the ruby interpreter, you should probably think about running valgrind with the following options: –partial-loads-ok=yes --undef-value-errors=no However, you probably shouldn’t be using valgrind to try to debug memory leaks in Ruby or Rails – valgrind is going to see memory malloc()ed by the Ruby interpreter for fast object allocation as a leak, which it isn’t. Plus, valgrind is going to tell you where in the C code (ruby interpreter source code) the leak “appears” to come from – which is totally useless for what you’re probably trying to do. I recommend using Bleak House instead to track down Ruby and Rails memory leaks: [http://blog.evanweaver.com/files/doc/fauna/bleak\_house/files/README.html](http://blog.evanweaver.com/files/doc/fauna/bleak_house/files/README.html) Good luck. ---
**Author:** ![santoshturamari](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/ee59a6/32.png) [@santoshturamari](https://www.ruby-forum.com/u/santoshturamari)\ **Post date:** [November 6, 2008, 5:23am UTC](https://www.ruby-forum.com/t/difficulty-in-understanding-the-valgrind-output-for-ror-app/152563/3 "2008-11-06T05:23:23Z")
Thank You for information.I ll try with bleak\_house. I recommend using Bleak House instead to track down Ruby and Rails memory leaks: [http://blog.evanweaver.com/files/doc/fauna/bleak\_house/files/README.html](http://blog.evanweaver.com/files/doc/fauna/bleak_house/files/README.html) ---
**Author:** ![santoshturamari](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/ee59a6/32.png) [@santoshturamari](https://www.ruby-forum.com/u/santoshturamari)\ **Post date:** [November 6, 2008, 6:33am UTC](https://www.ruby-forum.com/t/difficulty-in-understanding-the-valgrind-output-for-ror-app/152563/4 "2008-11-06T06:33:21Z")
Hi, I am trying with bleak\_house… it gives the dump… but in dump analyze I am getting the following output…I am not able to track this output also…pls help me out. bleak /tmp/bleak.6524.0.dump Displaying top 20 most common line/class pairs 456423 total objects 456423 filled heap slots 296358 free heap slots 408091 **null** : **null** : **node** 37164 **null** : **null** :String 2983 **null** : **null** :Class 1505 **null** : **null** :Array 1399 **null** : **null** :Regexp 1107 **null** : **null** :Proc 809 **null** : **null** :Hash 585 **null** : **null** : **varmap** 515 **null** : **null** :Module 259 **null** : **null** : **scope** 171 **null** : **null** :ActiveRecord::ConnectionAdapters::MysqlColumn 167 **null** : **null** :Range 167 **null** : **null** :ActionController::Routing::DividerSegment 86 **null** : **null** :Float 85 **null** : **null** :SOAP 74 **null** : **null** :ActionController::Routing::StaticSegment 73 **null** : **null** :XSD::QName 62 **null** : **null** 💎:Requirement 54 **null** : **null** 💎:Version 54 **null** : **null** :ActiveRecord::Reflection::AssociationReflection > However, you probably shouldn’t be using valgrind to try to debug > memory leaks in Ruby or Rails – valgrind is going to see memory > malloc()ed by the Ruby interpreter for fast object allocation as a > leak, which it isn’t. Plus, valgrind is going to tell you where in the > C code (ruby interpreter source code) the leak “appears” to come from > – which is totally useless for what you’re probably trying to do. > > I recommend using Bleak House instead to track down Ruby and Rails > memory leaks: > > [http://blog.evanweaver.com/files/doc/fauna/bleak\_house/files/README.html](http://blog.evanweaver.com/files/doc/fauna/bleak_house/files/README.html) > > Good luck. ---
**Author:** ![santoshturamari](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/ee59a6/32.png) [@santoshturamari](https://www.ruby-forum.com/u/santoshturamari)\ **Post date:** [November 6, 2008, 5:55pm UTC](https://www.ruby-forum.com/t/difficulty-in-understanding-the-valgrind-output-for-ror-app/152563/5 "2008-11-06T17:55:22Z")
On Nov 6, 12:33 am, Santosh T. \ wrote: > Hi, I am trying with bleak\_house… it gives the dump… but in dump > analyze I am getting the following output…I am not able to track this > output also…pls help me out. > > bleak /tmp/bleak.6524.0.dump > Displaying top 20 most common line/class pairs > 456423 total objects > 456423 filled heap slots > 296358 free heap slots > 408091 **null** : **null** : **node** Are you using eval() quite often in your code? That’s a big number. From the Bleak House documentation: It is normal to see lots of null:null references, especially for nodes. Using eval() too much can be a cause of node leaks. You can track eval() by using sourceline macros in your code: ``` eval("CODE", nil, __FILE__ , __LINE__ ) ``` > 167 **null** : **null** :Range > 167 **null** : **null** :ActionController::Routing::DividerSegment > 86 **null** : **null** :Float > 85 **null** : **null** :SOAP > 74 **null** : **null** :ActionController::Routing::StaticSegment > 73 **null** : **null** :XSD::QName > 62 **null** : **null** 💎:Requirement > 54 **null** : **null** 💎:Version > 54 **null** : **null** :ActiveRecord::Reflection::AssociationReflection The rest of these counts look reasonable to me. For example, running bleak house on an empty script that only requires rubygems and bleak\_house has, as its top output: 31778 **null** : **null** : **node** 23729 **null** : **null** :String 1945 **null** : **null** :Array Without knowing more about your app (Rails server? Standalone script? Daemon?) I can’t direct you more specifically – but if you’re using eval() (or a related function) then that’s where I’d start. If you’re not using eval, then you may want to make sure you’re reproducing the leak while running in bleak house.