Re: [PATCH 0/2] rcu_dereference_check_fdtable fix/cleanups

2014-01-10 Thread Paul E. McKenney
On Fri, Jan 10, 2014 at 04:34:59PM +0100, Oleg Nesterov wrote: > On 01/08, Paul E. McKenney wrote: > > > > On Wed, Jan 08, 2014 at 04:19:18PM +0100, Oleg Nesterov wrote: > > > On 01/08, Paul E. McKenney wrote: > > > > > > > > Another approach would be to add an argument to files_fdtable() > > > > t

Re: [PATCH 0/2] rcu_dereference_check_fdtable fix/cleanups

2014-01-10 Thread Oleg Nesterov
On 01/08, Paul E. McKenney wrote: > > On Wed, Jan 08, 2014 at 04:19:18PM +0100, Oleg Nesterov wrote: > > On 01/08, Paul E. McKenney wrote: > > > > > > Another approach would be to add an argument to files_fdtable() > > > that is zero normally and one for "we know we don't need RCU > > > protection.

Re: [PATCH 0/2] rcu_dereference_check_fdtable fix/cleanups

2014-01-09 Thread Paul E. McKenney
On Wed, Jan 08, 2014 at 04:19:18PM +0100, Oleg Nesterov wrote: > On 01/08, Paul E. McKenney wrote: > > > > I am not all that excited about invoking rcu_lock_acquire() outside > > of RCU... > > Yes, me too. That is why I thought about the helper with a good name, > see below. > > > Another approac

Re: [PATCH 0/2] rcu_dereference_check_fdtable fix/cleanups

2014-01-08 Thread Oleg Nesterov
On 01/08, Paul E. McKenney wrote: > > I am not all that excited about invoking rcu_lock_acquire() outside > of RCU... Yes, me too. That is why I thought about the helper with a good name, see below. > Another approach would be to add an argument to files_fdtable() > that is zero normally and one

Re: [PATCH 0/2] rcu_dereference_check_fdtable fix/cleanups

2014-01-08 Thread Paul E. McKenney
On Tue, Jan 07, 2014 at 07:12:58PM +0100, Oleg Nesterov wrote: > Hello. > > I tried to audit the users of thread_group_empty() (we need > to change it) and found rcu_my_thread_group_empty() which > looks wrong. > > The patches look simple, but I am not sure it is fine to use > rcu_lock_acquire()

[PATCH 0/2] rcu_dereference_check_fdtable fix/cleanups

2014-01-07 Thread Oleg Nesterov
Hello. I tried to audit the users of thread_group_empty() (we need to change it) and found rcu_my_thread_group_empty() which looks wrong. The patches look simple, but I am not sure it is fine to use rcu_lock_acquire() directly. Perhaps it makes sense to add a new helper? Note that we have more us