Re: [RFC 4/7] LTTng instrumentation kernel

[Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>]

* Mike Mason (mmlnx@us.ibm.com) wrote:
> snip
>> +void list_modules(void *call_data)
>> +{
>> +    /* Enumerate loaded modules */
>> +    struct list_head    *i;
>> +    struct module        *mod;
>> +    unsigned long refcount = 0;
>> +
>> +    mutex_lock(&module_mutex);
>> +    list_for_each(i, &modules) {
>> +        mod = list_entry(i, struct module, list);
>> +#ifdef CONFIG_MODULE_UNLOAD
>> +        refcount = local_read(&mod->ref[0].count);
>> +#endif
>> +        __trace_mark(0, list_module, call_data,
>> +                "name %s state %d refcount %lu",
>> +                mod->name, mod->state, refcount);
>> +    }
>> +    mutex_unlock(&module_mutex);
>> +}
>> +EXPORT_SYMBOL_GPL(list_modules);
>> +
>> /* Given an address, look for it in the module exception tables. */
>> const struct exception_table_entry *search_module_extables(unsigned long 
>> addr)
>> {
>
> What is the purpose of list_modules() in this patch?  Seems outside the 
> scope of the patches' intent.  I assume LTTng uses it for some purpose, but 
> it's not required to use the markers added by the patch.
>

Right, I should move it down in my patchset.

> Also, if list_modules() remains, the 0 should be removed from 
> "__trace_mark(0, ..." 
> Mike Mason

With the immediate values based markers, the 0 means an optimized
markers (non-generic). I use __trace_mark directly to be able to pass
the call_data argument.

Thanks for the review,

Mathieu

-- 
Mathieu Desnoyers
Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
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