| Message ID | 20130122073630.13822.99359.stgit@srivatsabhat.in.ibm.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
On Tue, Jan 22, 2013 at 01:06:34PM +0530, Srivatsa S. Bhat wrote: > Don't refer to stop_machine() in the CPU hotplug path, since we are going > to get rid of it. Also, move the comment referring to callback adoption > to the CPU_DEAD case, because that's where it happens now. > > Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Ouch! That comment is indeed obsolete and must die. I queued this to -rcu with your Signed-off-by. However, I omitted the added comment, as it is imcomplete -- it is easy to look at rcu_cleanup_dead_cpu() to see what it does. Thanx, Paul > --- > > kernel/rcutree.c | 9 ++++----- > 1 file changed, 4 insertions(+), 5 deletions(-) > > diff --git a/kernel/rcutree.c b/kernel/rcutree.c > index e441b77..ac94474 100644 > --- a/kernel/rcutree.c > +++ b/kernel/rcutree.c > @@ -2827,11 +2827,6 @@ static int __cpuinit rcu_cpu_notify(struct notifier_block *self, > break; > case CPU_DYING: > case CPU_DYING_FROZEN: > - /* > - * The whole machine is "stopped" except this CPU, so we can > - * touch any data without introducing corruption. We send the > - * dying CPU's callbacks to an arbitrarily chosen online CPU. > - */ > for_each_rcu_flavor(rsp) > rcu_cleanup_dying_cpu(rsp); > rcu_cleanup_after_idle(cpu); > @@ -2840,6 +2835,10 @@ static int __cpuinit rcu_cpu_notify(struct notifier_block *self, > case CPU_DEAD_FROZEN: > case CPU_UP_CANCELED: > case CPU_UP_CANCELED_FROZEN: > + /* > + * We send the dead CPU's callbacks to an arbitrarily chosen > + * online CPU. > + */ > for_each_rcu_flavor(rsp) > rcu_cleanup_dead_cpu(cpu, rsp); > break; >
On 02/09/2013 05:44 AM, Paul E. McKenney wrote: > On Tue, Jan 22, 2013 at 01:06:34PM +0530, Srivatsa S. Bhat wrote: >> Don't refer to stop_machine() in the CPU hotplug path, since we are going >> to get rid of it. Also, move the comment referring to callback adoption >> to the CPU_DEAD case, because that's where it happens now. >> >> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> > > Ouch! That comment is indeed obsolete and must die. > > I queued this to -rcu with your Signed-off-by. However, I omitted > the added comment, as it is imcomplete -- it is easy to look at > rcu_cleanup_dead_cpu() to see what it does. > Cool! I'll drop it from my patch series then. Thank you! Regards, Srivatsa S. Bhat
diff --git a/kernel/rcutree.c b/kernel/rcutree.c index e441b77..ac94474 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -2827,11 +2827,6 @@ static int __cpuinit rcu_cpu_notify(struct notifier_block *self, break; case CPU_DYING: case CPU_DYING_FROZEN: - /* - * The whole machine is "stopped" except this CPU, so we can - * touch any data without introducing corruption. We send the - * dying CPU's callbacks to an arbitrarily chosen online CPU. - */ for_each_rcu_flavor(rsp) rcu_cleanup_dying_cpu(rsp); rcu_cleanup_after_idle(cpu); @@ -2840,6 +2835,10 @@ static int __cpuinit rcu_cpu_notify(struct notifier_block *self, case CPU_DEAD_FROZEN: case CPU_UP_CANCELED: case CPU_UP_CANCELED_FROZEN: + /* + * We send the dead CPU's callbacks to an arbitrarily chosen + * online CPU. + */ for_each_rcu_flavor(rsp) rcu_cleanup_dead_cpu(cpu, rsp); break;
Don't refer to stop_machine() in the CPU hotplug path, since we are going to get rid of it. Also, move the comment referring to callback adoption to the CPU_DEAD case, because that's where it happens now. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> --- kernel/rcutree.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-)