Hi Erjiang, On 05/07/11 13:08, Erjiang Li wrote:
Hi All, I have been working on uClinux kernel on ARM platform recently, and I want to decrease the kernel stack size from 8K to 4K, i.e. change the following code (in include/asm-arm/thread_info.h): #define THREAD_SIZE_ORDER 1 #define THREAD_SIZE 8192 to #define THREAD_SIZE_ORDER 0 #define THREAD_SIZE 4096But after this modification, it fails to boot up linux on my ARM development board now. It stops at the position of pdflush_init(), and the functions calling chain is as following: ... ->pdflush_init()->start_one_pdflush_thread()->kthread_run()->kthread_create()->wait_for_completion()->wait_for_common()->do_wait_for_common()->schedule() In schedule() function, below code is executed repeatedly: if (unlikely(test_thread_flag(TIF_NEED_RESCHED))) goto need_resched; So the function schedule() can't return.
Have you checked that the stack at this point isn't larger than the 4k you have allowed for? I know the above call chain doesn't look too bad, but double check the current stack. And of course the real problem is that interrupts will come in and need more of the current kernel stack.
BTW, my uclinux version is 2.6.25, and my ARM cpu is MMU-less.
That is kind of old.
Can anyone give me some advice on this problem. I wonder if we can decrease THREAD_SIZE to 4K on ARM platform. Some one told me that ARM uClinux needs separate interrupt stack for 4K THREAD_SIZE. Is that true?
I haven't heard that. I use 4k stacks on uClinux/ColdFire builds and that seems ok on the systems I have used it on. Regards Greg ------------------------------------------------------------------------ Greg Ungerer -- Principal Engineer EMAIL: g...@snapgear.com SnapGear Group, McAfee PHONE: +61 7 3435 2888 8 Gardner Close FAX: +61 7 3217 5323 Milton, QLD, 4064, Australia WEB: http://www.SnapGear.com _______________________________________________ uClinux-dev mailing list uClinux-dev@uclinux.org http://mailman.uclinux.org/mailman/listinfo/uclinux-dev This message was resent by uclinux-dev@uclinux.org To unsubscribe see: http://mailman.uclinux.org/mailman/options/uclinux-dev
