On Thu, Aug 07, 2014 at 10:58:41AM -0700, Dave Hansen wrote: > > From: Dave Hansen <[email protected]> > > This is a bug fix that needs to be pushed to mainline before the > 3.17 release. > > Dave Jones reported seeing a bug from one of my TLB tracepoints: > > http://lkml.kernel.org/r/[email protected] > > According to Paul McKenney, the right way to fix this is adding > an _rcuidle suffix to the tracepoint. > > http://lkml.kernel.org/r/[email protected] > > This patch does just that. > > Signed-off-by: Dave Hansen <[email protected]> > Reported-by: Dave Jones <[email protected]>, > Cc: [email protected]
Reviewed-by: Paul E. McKenney <[email protected]> > --- > > b/arch/x86/mm/tlb.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff -puN arch/x86/mm/tlb.c~mm-fix-rcu-splat-from-tlb-tracepoints > arch/x86/mm/tlb.c > --- a/arch/x86/mm/tlb.c~mm-fix-rcu-splat-from-tlb-tracepoints 2014-08-07 > 10:55:43.312283542 -0700 > +++ b/arch/x86/mm/tlb.c 2014-08-07 10:56:49.763352575 -0700 > @@ -49,7 +49,13 @@ void leave_mm(int cpu) > if (cpumask_test_cpu(cpu, mm_cpumask(active_mm))) { > cpumask_clear_cpu(cpu, mm_cpumask(active_mm)); > load_cr3(swapper_pg_dir); > - trace_tlb_flush(TLB_FLUSH_ON_TASK_SWITCH, TLB_FLUSH_ALL); > + /* > + * This gets called in the idle path where RCU > + * functions differently. Tracing normally > + * uses RCU, so we have to call the tracepoint > + * specially here. > + */ > + trace_tlb_flush_rcuidle(TLB_FLUSH_ON_TASK_SWITCH, > TLB_FLUSH_ALL); > } > } > EXPORT_SYMBOL_GPL(leave_mm); > _ > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
