Messages in this thread |  | | Date | Tue, 4 Mar 2014 18:27:18 -0500 | From | Steven Rostedt <> | Subject | Re: [PATCH 05/48] percpu: Add preemption checks to __this_cpu ops |
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On Tue, 4 Mar 2014 14:27:27 -0800 Andrew Morton <akpm@linux-foundation.org> wrote:
> On Fri, 14 Feb 2014 14:18:46 -0600 Christoph Lameter <cl@linux.com> wrote: > > > [Patch depends on another patch in this series that introduces raw_cpu_ops] > > > > We define a check function in order to avoid trouble with the > > include files. Then the higher level __this_cpu macros are > > modified to invoke the preemption check. > > > > --- linux.orig/lib/smp_processor_id.c 2014-01-30 14:40:50.936519233 -0600 > > +++ linux/lib/smp_processor_id.c 2014-01-30 14:40:50.936519233 -0600 > > @@ -7,7 +7,7 @@ > > #include <linux/kallsyms.h> > > #include <linux/sched.h> > > > > -notrace unsigned int debug_smp_processor_id(void) > > +notrace static unsigned int check_preemption_disabled(char *what) > > { > > int this_cpu = raw_smp_processor_id(); > > > > @@ -38,9 +38,9 @@ > > if (!printk_ratelimit()) > > goto out_enable; > > > > - printk(KERN_ERR "BUG: using smp_processor_id() in preemptible [%08x] " > > - "code: %s/%d\n", > > - preempt_count() - 1, current->comm, current->pid); > > + printk(KERN_ERR "BUG: using %s in preemptible [%08x] code: %s/%d\n", > > + what, preempt_count() - 1, current->comm, current->pid); > > + > > print_symbol("caller is %s\n", (long)__builtin_return_address(0)); > > dump_stack(); > > I wonder if there's any point in printing __builtin_return_address. > Doesn't dump_stack() tell us the same thing?
When frame pointers are enabled, sure. But without frame pointers, I'm not so sure.
-- Steve
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