Re: [patch 02/10] Linux Kernel Markers, architecture independent code.

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

* Alexey Dobriyan (adobriyan@gmail.com) wrote:
> On Thu, May 10, 2007 at 09:12:41AM -0400, Mathieu Desnoyers wrote:
> > Linux Kernel Markers - Architecture Independant Code fix 2
> >
> > Fix trivial SMP bug in list_modules.
> 
> > --- linux-2.6-lttng.orig/kernel/module.c	2007-05-10 08:51:02.000000000 -0400
> > +++ linux-2.6-lttng/kernel/module.c	2007-05-10 08:51:06.000000000 -0400
> > @@ -2657,13 +2657,16 @@
> >  	/* Enumerate loaded modules */
> >  	struct list_head	*i;
> >  	struct module		*mod;
> > -	unsigned long refcount = 0;
> > +	unsigned long refcount;
> > +	int cpu;
> >
> >  	mutex_lock(&module_mutex);
> >  	list_for_each(i, &modules) {
> >  		mod = list_entry(i, struct module, list);
> > +		refcount = 0;
> >  #ifdef CONFIG_MODULE_UNLOAD
> > -		refcount = local_read(&mod->ref[0].count);
> > +		for_each_online_cpu(cpu)
> > +			refcount += local_read(&mod->ref[cpu].count);
> >  #endif //CONFIG_MODULE_UNLOAD
> 
> Still wrong: module_get on cpu X, cpu X hot unplugged. There is
> module_refcount() for you.

Ok, fixing. thanks.

-- 
Mathieu Desnoyers
Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F  BA06 3F25 A8FE 3BAE 9A68
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