| Message ID | 1346360743-3628-23-git-send-email-paulmck@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
On Thu, Aug 30, 2012 at 02:05:40PM -0700, Paul E. McKenney wrote: > From: Frederic Weisbecker <fweisbec@gmail.com> > > In the old times, the whole idle task was considered > as an RCU quiescent state. But as RCU became more and > more successful overtime, some RCU read side critical > section have been added even in the code of some > architectures idle tasks, for tracing for example. > > So nowadays, rcu_idle_enter() and rcu_idle_exit() must > be called by the architecture to tell RCU about the part > in the idle loop that doesn't make use of rcu read side > critical sections, typically the part that puts the CPU > in low power mode. > > This is necessary for RCU to find the quiescent states in > idle in order to complete grace periods. > > Add this missing pair of calls in the parisc's idle loop. > > Reported-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> > Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> > Cc: James E.J. Bottomley <jejb@parisc-linux.org> > Cc: Helge Deller <deller@gmx.de> > Cc: Parisc <linux-parisc@vger.kernel.org> > Cc: 3.2.x.. <stable@vger.kernel.org> > Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> > arch/parisc/kernel/process.c | 3 +++ > 1 files changed, 3 insertions(+), 0 deletions(-) > > diff --git a/arch/parisc/kernel/process.c b/arch/parisc/kernel/process.c > index d4b94b3..c54a4db 100644 > --- a/arch/parisc/kernel/process.c > +++ b/arch/parisc/kernel/process.c > @@ -48,6 +48,7 @@ > #include <linux/unistd.h> > #include <linux/kallsyms.h> > #include <linux/uaccess.h> > +#include <linux/rcupdate.h> > > #include <asm/io.h> > #include <asm/asm-offsets.h> > @@ -69,8 +70,10 @@ void cpu_idle(void) > > /* endless idle loop with no priority at all */ > while (1) { > + rcu_idle_enter(); > while (!need_resched()) > barrier(); > + rcu_idle_exit(); > schedule_preempt_disabled(); > check_pgt_cache(); > } > -- > 1.7.8 > -- To unsubscribe from this list: send the line "unsubscribe linux-parisc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/parisc/kernel/process.c b/arch/parisc/kernel/process.c index d4b94b3..c54a4db 100644 --- a/arch/parisc/kernel/process.c +++ b/arch/parisc/kernel/process.c @@ -48,6 +48,7 @@ #include <linux/unistd.h> #include <linux/kallsyms.h> #include <linux/uaccess.h> +#include <linux/rcupdate.h> #include <asm/io.h> #include <asm/asm-offsets.h> @@ -69,8 +70,10 @@ void cpu_idle(void) /* endless idle loop with no priority at all */ while (1) { + rcu_idle_enter(); while (!need_resched()) barrier(); + rcu_idle_exit(); schedule_preempt_disabled(); check_pgt_cache(); }