Memory leak with dev_add_pack()

[anish kumar]

> Hi!
>
> On 11:40 Sun 23 Jan     , Spiro Trikaliotis wrote:
> ...
>> * On Sat, Jan 22, 2011 at 08:18:05AM +0100 Michael Blizek wrote:
> ...
>> > - Which user grows is /proc/slabinfo? (If this file is emply or does 
>> > not
>> >   exist, you may meed to recompile the kernel to use slab instead of
>> >   sl[b-z]b)
>>
>> Thank you for the pointer, it might help.
>>
>> The objects which have changed the most on a mildly loaded network are:
>>
>> 25000 buffer_head
>>  5000 dentry
>>  5000 ext3_inode_cache
>>  5000 size-64
>>
>> The number if the number of more active object after approx. 20h of
>> letting it run on the mildly loaded network.
>>
>> Note that the ext3_inode_cache might have grown because I was regularly
>> writing a new log file from slabinfo (slabinfo --once > slabinfo.`date
>> +...`)
>>
>> Thus, I would expect I am leaking buffer_head.
>
> The funny point is that buffer_head belongs to the filesystem subsystem. 
> What
> file systems are you using? Could it be that your code just triggers the
> memory leak, because data is logged to disk, e.g. to /var/log/kern.log ?
I did small experiment with your code.I removed all your logs which were 
getting
logged in kernel buffers(kern.log).With this change i checked the "meminfo" 
and found that
the memory leaking is almost same as compared to normal case(with no change 
in your code).

>
> I have tried your program on my virtual machine (2.6.28) and could see any
> leak, but maybe data is leaked very slowly...
i confirm that data is leaking very slowly (below is the output i got on my 
ubuntu machine
with removed logs from your code).

$date
Sun Jan 23 19:13:47 RET 2011

$ head -n5 /proc/meminfo
MemTotal:        1018172 kB
MemFree:          373708 kB
Buffers:           32232 kB
Cached:           296004 kB
SwapCached:            0 kB

$ date
Sun Jan 23 19:15:03 RET 2011

$ head -n5 /proc/meminfo
MemTotal:        1018172 kB
MemFree:          373584 kB
Buffers:           32248 kB
Cached:           296004 kB
SwapCached:            0 kB

With logs enabled in your code i can see marginal increase in leaking 
memory.
I can defintely see the memory leaking with your ko and will investigate 
further as to the reason.
Hopefully kmemleak will lead us somewhere.

>
> -Michi
> -- 
> programing a layer 3+4 network protocol for mesh networks
> see http://michaelblizek.twilightparadox.com
>
>
> _______________________________________________
> Kernelnewbies mailing list
> Kernelnewbies at kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies