On Thu, Mar 24, 2011 at 12:08, sakthi selvam <sakthi.cdm@gmail.com> wrote:

But in my case, cleanup module also available in memory, after loading the module. I used to check using the file in /proc/kallsyms for the availability of cleanup module in memory.

AFAIK, such thing could happen due to certain data structure(s) from that module that are continously accessed or locked. So, to avoid race condition ( and missing pointer), keeping the module in memory is the right way to do. But of course, AFAIK too, you can try rmmod -f. But the risk is all yours. -- regards, Mulyadi Santosa Freelance Linux trainer and consultant blog: the-hydra.blogspot.com training: mulyaditraining.blogspot.com

Dear all, Thanks for your suggestion. Finally, I identified the solution for the permanent issued I faced after loading my kernel module. The solution is the kernel macro; 'USE_IMMEDIATE' has to be defined (to be given as -DUSE_IMMEDIATE along with compiler flags) during compilation of my module. Actually, I don't know much deep about the usage of this kernel macro and how it resolves the issue, but one thing I came to know that it was used during module relocation while inserting the module. If anyone help me to get know much about it, then it will be fine. Also, for your information, I have used my own Makefile for compilation of kernel loadable modules. So, I have to add myself this macro to get rid of this permanent issue. Another fine solution is, you can make use of kernel build Makefile itself (if linux kernel version is above 2.4) to build your kernel loadable modules. Because it itself include all default macros and flags needed for compilation of your module. I have specified below the sample Makefile for compiling kernel loadable modules with kernel build Makefile. *Reference:* obj-m += hello.o all: make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules clean: make -C /lib/modules/$(shell uname -r)/build M=$(PWD) clean Regards, Sakthi On Thu, Mar 24, 2011 at 10:38 AM, sakthi selvam <sakthi.cdm@gmail.com>wrote:

Dear All,

Need your assistance:

Currently I am using Wind River Linux distribution OS with kernel version 2.6.27.39 and Wind River version pne-3. After loading of my kernel module, I found it was permanent in the kernel using lsmod (for ex see below Ref 1). When I tried to remove, it was displaying as “ERROR: Removing 'hsl_module': Device or resource busy”. For your information, the same module is working fine with the Wind River pne-2 Linux Distribution OS with kernel version 2.6.21. From the kernel source, I came to know that only possibility of showing permanent is “if there is non-availability of cleanup_module and with the availability of init_module”.

But in my case, cleanup module also available in memory, after loading the module. I used to check using the file in /proc/kallsyms for the availability of cleanup module in memory.

Thanks for reading. Prompt reply is expected to identify the root cause.

Ref 1: Module Size Used by hsl_module 530454 0 [permanent]

Thanks, Sakthi Selvam