Messages in this thread | | | Date | Sun, 12 Mar 2006 11:23:17 +0800 | From | "James Yu" <> | Subject | weird behavior from kernel |
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Hi folks,
I am modifying linux-2.4.18 for ARM (based on S3C2410), I enable only the timer interrupt and disable all the others in "init" thread before "execve("/sbin/init",argv_init,envp_init);" is taking place. I also create two kernel threads by invoking "kernel_thread" right after disbling the interrupts. This is how the kernel thread looks like:
923 void eos_1(void) - 924 { | 925 DECLARE_WAITQUEUE(wait, current); | 926 | 927 while (1) |- 928 { || 929 printk("\n%s[%d], period:%d, deadline:%d, jiffies:%d.\n", || 930 current->comm, current->pid, current->period, current->deadline, jiffies); || 931 eos_tail(); || 932 } | 933 }
905 #define eos_tail() \ - 906 do { \ | 907 static int deadline = 0; \ | 908 if ((current->deadline - jiffies) > 0) \ |- 909 { \ || 910 deadline = current->deadline; \ || 911 current->deadline = deadline + current->period; \ || 912 sleep_on_timeout(&wait, (deadline - jiffies)); \ || 913 } \ | 914 else \ |- 915 { \ || 916 printk("\n!!! %s[%d] missed deadline !!!\n", current->comm, current->pid); \ || 917 return (0); \ || 918 } \ | 919 } while(0)
Now I am trying to modify the "schedule" function. I insert the following segment into schedule function after the part that re-calculate counters --> if(unlikely(!c)).
|- 634 { || 635 int latch = 0; || 636 || 637 list_for_each(tmp, &runqueue_head) ||- 638 { ||| 639 //p = list_entry(tmp, struct task_struct, run_list); ||| 640 latch = latch + 1; ||| 641 } || 642 printk("{%d}", latch); || 643 }
This is where weird thing happens! If I uncomment line 639, kernel complains that I am passing an illegal value into "sleep_on_timeout", which is called in my kernel thread inside "eos_tail". I copy both line 637 and 639 from schedule itself (they were used to pick next job to run).
I am simply doing copy & paste inside "schedule", can someone please tell me what is happening ?
Thanks a lot, -- James cyu021@gmail.com - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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