Thanks to all for their resonse! Ok, just one thing - When I do lsmod - it shows the memory used by loaded LKMs. So if there is a leak in LKM1 then after executing the function (which is doing kmalloc but forgetting to do kfree) of LKM1, lsmod should report an increased memory usage by LKM1. Am I right?
Thanks On 1/23/08, Bernd Petrovitsch <[EMAIL PROTECTED]> wrote: > > On Mit, 2008-01-23 at 18:31 +0530, Manish Katiyar wrote: > [...] > > So If i do a kzalloc() in my module and then unload my module without > > freeing it, it will be a memory leak...........Am i right ?? .. Or the > > Yes. > > > kernel is intelligent enough to check and free those memory buffers > > during unload of the module ? > > No. > That is actually a not-trivial problem[0] as you want to kfree() a > buffer when the last pointer to it vanishes. And there is no way (except > explicit coding it that way) to e.g. have automatic reference-counting > like the typical scripting language (perl, php, ...) or Java. > For a kernel, there a lots of places where reference counting is just a > waste of memory and CPU power so no one needs/want's it there. > > Next point is: Module unloading happens quite seldom in real life. So it > makes no sense to invest signifikant amount of work just for that one > operation (and there are voice who propose to never unload a module in > real life). > Next: Module unloading is not the only source of memory leaks. So you > have to make sure anyways that your module doesn't loose memory. > Typical error is to allocate memory in an open() sys-call-handler and > forget to free it on a close() handler. > > Bernd > > [0]: Google for "garbage collection". > -- > Firmix Software GmbH http://www.firmix.at/ > mobil: +43 664 4416156 fax: +43 1 7890849-55 > Embedded Linux Development and Services > > > > -- > To unsubscribe from this list: send an email with > "unsubscribe kernelnewbies" to [EMAIL PROTECTED] > Please read the FAQ at http://kernelnewbies.org/FAQ > >
