Messages in this thread | | | Date | Tue, 21 Apr 2009 11:41:35 +0800 | From | Lai Jiangshan <> | Subject | Re: [PATCH] netfilter: use per-cpu recursive lock (v11) |
| |
Stephen Hemminger wrote: > +/** > + * xt_table_info_rdlock_bh - recursive read lock for xt table info > + * > + * Table processing calls this to hold off any changes to table > + * (on current CPU). Always leaves with bottom half disabled. > + * If called recursively, then assumes bh/preempt already disabled. > + */ > +void xt_info_rdlock_bh(void) > +{ > + struct xt_info_lock *lock; > + > + preempt_disable(); > + lock = &__get_cpu_var(xt_info_locks); > + if (likely(++lock->depth == 0))
Maybe I missed something. I think softirq may be still enabled here. So what happen when xt_info_rdlock_bh() called recursively here?
> + spin_lock_bh(&lock->lock); > + preempt_enable_no_resched(); > +} > +EXPORT_SYMBOL_GPL(xt_info_rdlock_bh); > +
Is this OK for you:
void xt_info_rdlock_bh(void) { struct xt_info_lock *lock;
local_bh_disable(); lock = &__get_cpu_var(xt_info_locks); if (likely(++lock->depth == 0)) spin_lock(&lock->lock); }
Lai.
| |