On Tue, Jul 27, 2010 at 19:18, Andrew Morton wrote:On Mon, 26 Jul 2010 10:49:50 +0200 Michal Simek wrote:start/stop_critical_timing function for preemptirqsoff, preemptoffSeems that this will also affect blackfin, mn10300 and score. I guess
and irqsoff tracers contains atomic_inc and atomic_dec operations.
Atomic operations used local_irq_save/restore macros to ensure
atomic access but they are traced by the same function which is causing
recursion problem.
The reason is when these tracers are turn ON then local_irq_save/restore
macros are changed in include/linux/irqflags.h to call trace_hardirqs_on/off
which call start/stop_critical_timing.
Microblaze was affected because use generic atomic implementation.
they aren't supporting tracing yet?
do you mean TRACE_IRQFLAGS_SUPPORT ? Blackfin should ... my
understanding was that arches just needed to implement asm/irqflags.h
for it.