Messages in this thread | | | Date | Thu, 5 Feb 2015 15:57:12 +0100 | Subject | Re: linux-next: Tree for Feb 4 | From | Sedat Dilek <> |
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On Thu, Feb 5, 2015 at 8:14 AM, Dave Hansen <dave@sr71.net> wrote: > On 02/04/2015 05:53 PM, Sedat Dilek wrote: >> The architecture-specific switch_mm() function can be called by offline >> CPUs, but includes event tracing, which cannot be legally carried out >> on offline CPUs. This results in a lockdep-RCU splat. This commit fixes >> this splat by omitting the tracing when the CPU is offline. > ... >>>> >> > load_cr3(next->pgd); >>>> >> > - trace_tlb_flush(TLB_FLUSH_ON_TASK_SWITCH, TLB_FLUSH_ALL); >>>> >> > + if (cpu_online(smp_processor_id())) >>>> >> > + trace_tlb_flush(TLB_FLUSH_ON_TASK_SWITCH, TLB_FLUSH_ALL); > > Is this, perhaps, something that we should be doing in the generic trace > code so that all of the trace users don't have to worry about it? Also, > this patch will add overhead to the code when tracing is off. It would > be best if we could manage to make the cpu_online() check only in the > cases where the tracepoint is on.
Hi Dave,
thanks for your feedback.
I have just seen that I again see the call-trace.
Maybe you can discuss with Paul and others or offer a proposal patch.
I should really do something for my recovery (influenza). Instead of laying lazy in my bed I thought to update my Linux kernels and graphics driver stack which made me happy.
Regards, - Sedat -
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