Messages in this thread | | | Subject | Re: [tipc-discussion] [PATCH net/tipc] Replace rcu_swap_protected() with rcu_replace_pointer() | From | Ying Xue <> | Date | Thu, 12 Dec 2019 14:14:20 +0800 |
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On 12/12/19 2:46 AM, Paul E. McKenney wrote: > On Wed, Dec 11, 2019 at 12:42:00PM +0800, Ying Xue wrote: >> On 12/11/19 10:00 AM, Tuong Lien Tong wrote: >>>> >>>> /* Move passive key if any */ >>>> if (key.passive) { >>>> - tipc_aead_rcu_swap(rx->aead[key.passive], tmp2, &rx->lock); >>>> + tmp2 = rcu_replace_pointer(rx->aead[key.passive], tmp2, >>> &rx->lock); >>> The 3rd parameter should be the lockdep condition checking instead of the >>> spinlock's pointer i.e. "lockdep_is_held(&rx->lock)"? >>> That's why I'd prefer to use the 'tipc_aead_rcu_swap ()' macro, which is >>> clear & concise at least for the context here. It might be re-used later as >>> well... >>> >> >> Right. The 3rd parameter of rcu_replace_pointer() should be >> "lockdep_is_held(&rx->lock)" instead of "&rx->lock". > > Like this?
Yes, I think it's better to set the 3rd parameter of rcu_replace_pointer() with "lockdep_is_held(&rx->lock)".
> > Thanx, Paul > > ------------------------------------------------------------------------ > > commit 575bb4ba1b22383656760feb3d122e11656ccdfd > Author: Paul E. McKenney <paulmck@kernel.org> > Date: Mon Dec 9 19:13:45 2019 -0800 > > net/tipc: Replace rcu_swap_protected() with rcu_replace_pointer() > > This commit replaces the use of rcu_swap_protected() with the more > intuitively appealing rcu_replace_pointer() as a step towards removing > rcu_swap_protected(). > > Link: https://lore.kernel.org/lkml/CAHk-=wiAsJLw1egFEE=Z7-GGtM6wcvtyytXZA1+BHqta4gg6Hw@mail.gmail.com/ > Reported-by: Linus Torvalds <torvalds@linux-foundation.org> > Reported-by: kbuild test robot <lkp@intel.com> > Signed-off-by: Paul E. McKenney <paulmck@kernel.org> > [ paulmck: Updated based on Ying Xue and Tuong Lien Tong feedback. ] > Cc: Jon Maloy <jon.maloy@ericsson.com> > Cc: Ying Xue <ying.xue@windriver.com> > Cc: "David S. Miller" <davem@davemloft.net> > Cc: <netdev@vger.kernel.org> > Cc: <tipc-discussion@lists.sourceforge.net> > > diff --git a/net/tipc/crypto.c b/net/tipc/crypto.c > index 990a872..c8c47fc 100644 > --- a/net/tipc/crypto.c > +++ b/net/tipc/crypto.c > @@ -257,9 +257,6 @@ static char *tipc_key_change_dump(struct tipc_key old, struct tipc_key new, > #define tipc_aead_rcu_ptr(rcu_ptr, lock) \ > rcu_dereference_protected((rcu_ptr), lockdep_is_held(lock)) > > -#define tipc_aead_rcu_swap(rcu_ptr, ptr, lock) \ > - rcu_swap_protected((rcu_ptr), (ptr), lockdep_is_held(lock)) > - > #define tipc_aead_rcu_replace(rcu_ptr, ptr, lock) \ > do { \ > typeof(rcu_ptr) __tmp = rcu_dereference_protected((rcu_ptr), \ > @@ -1189,7 +1186,7 @@ static bool tipc_crypto_key_try_align(struct tipc_crypto *rx, u8 new_pending) > > /* Move passive key if any */ > if (key.passive) { > - tipc_aead_rcu_swap(rx->aead[key.passive], tmp2, &rx->lock); > + tmp2 = rcu_replace_pointer(rx->aead[key.passive], tmp2, lockdep_is_held(&rx->lock)); > x = (key.passive - key.pending + new_pending) % KEY_MAX; > new_passive = (x <= 0) ? x + KEY_MAX : x; > } >
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