Re: how do you debug ref leaks?

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 09/17/2014 10:13 PM, Pranith Kumar Karampuri wrote:
hi,
     Till now the only method I used to find ref leaks effectively is to
find what operation is causing ref leaks and read the code to find if
there is a ref-leak somewhere. Valgrind doesn't solve this problem
because it is reachable memory from inode-table etc. I am just wondering
if there is an effective way anyone else knows of. Do you guys think we
need a better mechanism of finding refleaks? At least which decreases
the search space significantly i.e. xlator y, fop f etc? It would be
better if we can come up with ways to integrate statedump and this infra
just like we did for mem-accounting.

One way I thought was to introduce new apis called
xl_fop_dict/inode/fd_ref/unref (). Each xl keeps an array of num_fops
per inode/dict/fd and increments/decrements accordingly. Dump this info
on statedump.

I myself am not completely sure about this idea. It requires all xlators
to change.

Any ideas?

On a debug build we can use backtrace information stashed per ref and unref, this will give us history of refs taken and released. Which will also give the code path where ref was taken and released.

It is heavy weight, so not for non-debug setups, but if a problem is reproducible this could be a quick way to check who is not releasing the ref's or have a history of the refs and unrefs to dig better into code.

Shyam
_______________________________________________
Gluster-devel mailing list
Gluster-devel@xxxxxxxxxxx
http://supercolony.gluster.org/mailman/listinfo/gluster-devel




[Index of Archives]     [Gluster Users]     [Ceph Users]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [IETF Annouce]     [Security]     [Bugtraq]     [Linux]     [Linux OMAP]     [Linux MIPS]     [eCos]     [Asterisk Internet PBX]     [Linux API]

  Powered by Linux