Re: [PATCH 05/37] kdb: core for kgdb back end

From: Jason Wessel
Date: Mon Dec 28 2009 - 14:28:20 EST


Peter Zijlstra wrote:
> On Wed, 2009-12-23 at 15:19 -0600, Jason Wessel wrote:
>> +kdb_prio(char *name, struct rt_prio_array *array, kdb_printf_t xxx_printf,
[..]
>> +kdb_runqueue(unsigned long cpu, kdb_printf_t xxx_printf)
[..]
>
> So what is this code supposed to do? It looks like it simply cannot be
> correct.
>

Beyond the fact that the code may not be right, it is a small part of a kdb module which is not included, and these functions can immediately disappear. For reference, the original kdb module was called "kdbm_sched" and I believe it was intended as an aid to help debug the scheduler and process priorities in earlier versions of the kernel.

I have removed all this code and reduced the patch to kernel/sched.c to the following. The reason we need the attached patch is to be able to call curr_task() for kdb to perform some basic per cpu task analysis while the system is stopped.

Thanks,
Jason.

--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -9784,9 +9784,9 @@ void normalize_rt_tasks(void)

#endif /* CONFIG_MAGIC_SYSRQ */

-#ifdef CONFIG_IA64
+#if defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB)
/*
- * These functions are only useful for the IA64 MCA handling.
+ * These functions are only useful for the IA64 MCA handling, or kdb.
*
* They can only be called when the whole system has been
* stopped - every CPU needs to be quiescent, and no scheduling
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