# How to find out memory leak? **URL:** \ **Category:** Ruby\ **Created:** [February 25, 2008, 4:31pm UTC](https://www.ruby-forum.com/t/how-to-find-out-memory-leak/186734 "2008-02-25T16:31:00Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![pluskid](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/ba8739/32.png) [@pluskid](https://www.ruby-forum.com/u/pluskid)\ **Post date:** [February 25, 2008, 4:31pm UTC](https://www.ruby-forum.com/t/how-to-find-out-memory-leak/186734/1 "2008-02-25T16:31:00Z")
Hi, all! I’m having memory leak problem with my program, but can’t find where’s the leak. I have a program written in pure-Ruby. It implemented a Chinese word segment algorithm. I call `segment(text)' to get the result. But each time I call `segment’, the memory usage of my program (Ruby) increased several handred K- bytes – the number of bytes of increment is roughly equal during each call. I can see from outside (using `ps' or `top’) that the memory is leaking. But I can’t find where the leaking goes. I tried to use ObjectSpace.each\_object to find out what leaks. I followed this article > **[Memory leak profiling with Rails :: scottstuff.net](https://scottstuff.net/blog/articles/2006/08/17/memory-leak-profiling-with-rails/index.html)** > > One of my long-running problems with Rails (and Ruby in general) is that it’s difficult to debug memory leaks. I’ve had a number of cases where I’ve stuck something into a long-lived array or hash and discovered much later that my Ruby process was... and compare the objects after each call to `segment’. What surprise me is that there’s no object leaked between each call. The number of objects after each call is roughly equal. I also tried bleak\_house: > **[Evan Weaver](https://evan.vc)** > > I'm an engineer, founder, and angel investor in software infrastructure, developer tools, social media, ecommerce, and AI. I don’t precisely how to use it. I just dump a snapshot after each call to `segment' and use `bleak’ to analyze the result. However, it also shows no leak. But if there’s no leak, where goes the memory? Here’s the result of using the `pmap’ tool to inspect the running Ruby process: 933: /usr/bin/ruby1.8 /usr/bin/rake PROFILE=false test:many 08048000 4K r-x-- /usr/bin/ruby1.8 08049000 4K rw— /usr/bin/ruby1.8 0804a000 33412K rw— [anon] b74a8000 7016K rw— [anon] b7b82000 16K r-x-- /usr/lib/ruby/1.8/i486-linux/strscan.so b7b86000 4K rw— /usr/lib/ruby/1.8/i486-linux/strscan.so b7b87000 16K r-x-- /var/lib/gems/1.8/gems/ruby-prof-0.6.0/lib/ ruby\_prof.so b7b8b000 4K rw— /var/lib/gems/1.8/gems/ruby-prof-0.6.0/lib/ ruby\_prof.so b7b8c000 1192K rw— [anon] b7cb6000 1308K r-x-- /lib/i686/cmov/libc-2.7.so b7dfd000 4K r---- /lib/i686/cmov/libc-2.7.so b7dfe000 8K rw— /lib/i686/cmov/libc-2.7.so b7e00000 12K rw— [anon] b7e03000 140K r-x-- /lib/i686/cmov/libm-2.7.so b7e26000 8K rw— /lib/i686/cmov/libm-2.7.so b7e28000 36K r-x-- /lib/i686/cmov/libcrypt-2.7.so b7e31000 8K rw— /lib/i686/cmov/libcrypt-2.7.so b7e33000 156K rw— [anon] b7e5a000 8K r-x-- /lib/i686/cmov/libdl-2.7.so b7e5c000 8K rw— /lib/i686/cmov/libdl-2.7.so b7e5e000 4K rw— [anon] b7e5f000 80K r-x-- /lib/i686/cmov/libpthread-2.7.so b7e73000 8K rw— /lib/i686/cmov/libpthread-2.7.so b7e75000 8K rw— [anon] b7e77000 756K r-x-- /usr/lib/libruby1.8.so.1.8.6 b7f34000 8K rw— /usr/lib/libruby1.8.so.1.8.6 b7f36000 64K rw— [anon] b7f48000 8K rw— [anon] b7f4a000 8K r-x-- /usr/lib/ruby/1.8/i486-linux/etc.so b7f4c000 4K rw— /usr/lib/ruby/1.8/i486-linux/etc.so b7f4d000 12K r-x-- /usr/lib/ruby/1.8/i486-linux/thread.so b7f50000 4K rw— /usr/lib/ruby/1.8/i486-linux/thread.so b7f51000 8K rw— [anon] b7f53000 104K r-x-- /lib/ld-2.7.so b7f6d000 8K rw— /lib/ld-2.7.so bfdea000 116K rw— [stack] ffffe000 4K r-x-- [anon] total 44568K The section “0804a000 33412K rw— [anon]” increased after each call. I’ve no idea now. Do you have any suggestion for me? ---
**Author:** ![pluskid](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/ba8739/32.png) [@pluskid](https://www.ruby-forum.com/u/pluskid)\ **Post date:** [February 25, 2008, 4:51pm UTC](https://www.ruby-forum.com/t/how-to-find-out-memory-leak/186734/2 "2008-02-25T16:51:49Z")
On Mon, Feb 25, 2008 at 4:29 PM, pluskid [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > number of bytes of increment is roughly equal during each call. > is that > and use `bleak’ to analyze the result. However, it also shows no leak. > b74a8000 7016K rw— [anon] > b7e00000 12K rw— [anon] > b7e75000 8K rw— [anon] > b7f6d000 8K rw— /lib/ld-2.7.so > bfdea000 116K rw— [stack] > ffffe000 4K r-x-- [anon] > total 44568K > > The section “0804a000 33412K rw— [anon]” increased after each > call. I’ve no idea now. Do you have any suggestion for me? This is what I have read here or somewhere else, and I an not knowledgeable enough to confirm it, anyway: Ruby allocs space from the OS in large chunks (initially 8 MB, and each other chunk is bigger by a predefined coefficient). Any chunk can be returned to the OS only if it is empty - so if your memory is fragmented, ruby will have to alloc new chunks in order to satisfy ruby script being run. If this is true, it means: the order and size of your allocations is important. Especially order of the allocations that you later release relative to those that you don’t. ---
**Author:** ![pluskid](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/ba8739/32.png) [@pluskid](https://www.ruby-forum.com/u/pluskid)\ **Post date:** [February 26, 2008, 11:01am UTC](https://www.ruby-forum.com/t/how-to-find-out-memory-leak/186734/3 "2008-02-26T11:01:46Z")
If that is the case, that might be quite random, istead of seeing the increment of every call roughly equal. ☹ 2008/2/25, Jano S. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid):