| Message ID | 20230729142738.222208-4-joel@joelfernandes.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | misc RCU fixes and cleanups | expand |
On Sat, Jul 29, 2023 at 02:27:33PM +0000, Joel Fernandes (Google) wrote: > This is needed to make the next patch work correctly as we rely on the > strength of the wakeup when comparing deferred-wakeup types across > different CPUs. > > Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> > --- > kernel/rcu/tree.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h > index 192536916f9a..0f40a9c2b78d 100644 > --- a/kernel/rcu/tree.h > +++ b/kernel/rcu/tree.h > @@ -288,8 +288,8 @@ struct rcu_data { > > /* Values for nocb_defer_wakeup field in struct rcu_data. */ > #define RCU_NOCB_WAKE_NOT 0 > -#define RCU_NOCB_WAKE_BYPASS 1 > -#define RCU_NOCB_WAKE_LAZY 2 > +#define RCU_NOCB_WAKE_LAZY 1 > +#define RCU_NOCB_WAKE_BYPASS 2 > #define RCU_NOCB_WAKE 3 > #define RCU_NOCB_WAKE_FORCE 4 Good change but make sure to audit all the occurences of RCU_NOCB_WAKE_LAZY and RCU_NOCB_WAKE_BYPASS. For example this breaks do_nocb_deferred_wakeup_timer() that will now ignore RCU_NOCB_WAKE_LAZY timers. Thanks.
On Tue, Aug 29, 2023 at 6:53 AM Frederic Weisbecker <frederic@kernel.org> wrote: > > On Sat, Jul 29, 2023 at 02:27:33PM +0000, Joel Fernandes (Google) wrote: > > This is needed to make the next patch work correctly as we rely on the > > strength of the wakeup when comparing deferred-wakeup types across > > different CPUs. > > > > Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> > > --- > > kernel/rcu/tree.h | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h > > index 192536916f9a..0f40a9c2b78d 100644 > > --- a/kernel/rcu/tree.h > > +++ b/kernel/rcu/tree.h > > @@ -288,8 +288,8 @@ struct rcu_data { > > > > /* Values for nocb_defer_wakeup field in struct rcu_data. */ > > #define RCU_NOCB_WAKE_NOT 0 > > -#define RCU_NOCB_WAKE_BYPASS 1 > > -#define RCU_NOCB_WAKE_LAZY 2 > > +#define RCU_NOCB_WAKE_LAZY 1 > > +#define RCU_NOCB_WAKE_BYPASS 2 > > #define RCU_NOCB_WAKE 3 > > #define RCU_NOCB_WAKE_FORCE 4 > > Good change but make sure to audit all the occurences of > RCU_NOCB_WAKE_LAZY and RCU_NOCB_WAKE_BYPASS. For example this breaks > do_nocb_deferred_wakeup_timer() that will now ignore RCU_NOCB_WAKE_LAZY > timers. > Ah I did do an audit, but missed this one. So then I think do_nocb_deferred_wakeup_timer() should pass the weakest one (RCU_NOCB_WAKE_LAZY) to do_nocb_deferred_wakeup_common(). Thanks a lot Frederic! I will take a deeper dive into this and author users of RCU_NOCB_WAKE* and repost soon. - Joel
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h index 192536916f9a..0f40a9c2b78d 100644 --- a/kernel/rcu/tree.h +++ b/kernel/rcu/tree.h @@ -288,8 +288,8 @@ struct rcu_data { /* Values for nocb_defer_wakeup field in struct rcu_data. */ #define RCU_NOCB_WAKE_NOT 0 -#define RCU_NOCB_WAKE_BYPASS 1 -#define RCU_NOCB_WAKE_LAZY 2 +#define RCU_NOCB_WAKE_LAZY 1 +#define RCU_NOCB_WAKE_BYPASS 2 #define RCU_NOCB_WAKE 3 #define RCU_NOCB_WAKE_FORCE 4
This is needed to make the next patch work correctly as we rely on the strength of the wakeup when comparing deferred-wakeup types across different CPUs. Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> --- kernel/rcu/tree.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)