| Message ID | 1346360743-3628-26-git-send-email-paulmck@linux.vnet.ibm.com |
|---|---|
| State | Accepted |
| Commit | 93482f4ef1093f5961a63359a34612183d6beea0 |
| Headers | show |
On Thu, Aug 30, 2012 at 02:05:43PM -0700, Paul E. McKenney wrote: > From: "Paul E. McKenney" <paul.mckenney@linaro.org> > > Traditionally, the entire idle task served as an RCU quiescent state. > But when RCU read side critical sections started appearing within the > idle loop, this traditional strategy became untenable. The fix was to > create new RCU APIs named rcu_idle_enter() and rcu_idle_exit(), which > must be called by each architecture's idle loop so that RCU can tell > when it is safe to ignore a given idle CPU. > > Unfortunately, this fix was never applied to ia64, a shortcoming remedied > by this commit. > > Reported by: Tony Luck <tony.luck@intel.com> > Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> > Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> > Tested by: Tony Luck <tony.luck@intel.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> > arch/ia64/kernel/process.c | 3 +++ > 1 files changed, 3 insertions(+), 0 deletions(-) > > diff --git a/arch/ia64/kernel/process.c b/arch/ia64/kernel/process.c > index dd6fc14..3e316ec 100644 > --- a/arch/ia64/kernel/process.c > +++ b/arch/ia64/kernel/process.c > @@ -29,6 +29,7 @@ > #include <linux/kdebug.h> > #include <linux/utsname.h> > #include <linux/tracehook.h> > +#include <linux/rcupdate.h> > > #include <asm/cpu.h> > #include <asm/delay.h> > @@ -279,6 +280,7 @@ cpu_idle (void) > > /* endless idle loop with no priority at all */ > while (1) { > + rcu_idle_enter(); > if (can_do_pal_halt) { > current_thread_info()->status &= ~TS_POLLING; > /* > @@ -309,6 +311,7 @@ cpu_idle (void) > normal_xtp(); > #endif > } > + rcu_idle_exit(); > schedule_preempt_disabled(); > check_pgt_cache(); > if (cpu_is_offline(cpu)) > -- > 1.7.8 >
diff --git a/arch/ia64/kernel/process.c b/arch/ia64/kernel/process.c index dd6fc14..3e316ec 100644 --- a/arch/ia64/kernel/process.c +++ b/arch/ia64/kernel/process.c @@ -29,6 +29,7 @@ #include <linux/kdebug.h> #include <linux/utsname.h> #include <linux/tracehook.h> +#include <linux/rcupdate.h> #include <asm/cpu.h> #include <asm/delay.h> @@ -279,6 +280,7 @@ cpu_idle (void) /* endless idle loop with no priority at all */ while (1) { + rcu_idle_enter(); if (can_do_pal_halt) { current_thread_info()->status &= ~TS_POLLING; /* @@ -309,6 +311,7 @@ cpu_idle (void) normal_xtp(); #endif } + rcu_idle_exit(); schedule_preempt_disabled(); check_pgt_cache(); if (cpu_is_offline(cpu))