Re: [PATCH -rt] Revert "net: use synchronize_rcu_expedited()"

2015-10-30 Thread David Miller
From: Eric Dumazet Date: Tue, 27 Oct 2015 07:18:01 -0700 > On Tue, 2015-10-27 at 07:31 -0500, Josh Cartwright wrote: > >> Okay, yes, I like the first suggestion better as well, I've included a >> patch below that does just that. I hope you don't mind me turning it >> into a Suggested-by :). >>

Re: [PATCH -rt] Revert "net: use synchronize_rcu_expedited()"

2015-10-28 Thread Paul E. McKenney
On Wed, Oct 28, 2015 at 03:34:00AM -0500, Josh Cartwright wrote: > On Tue, Oct 27, 2015 at 04:15:59PM -0700, Paul E. McKenney wrote: > > On Tue, Oct 27, 2015 at 08:27:53AM -0700, Eric Dumazet wrote: > > > On Tue, 2015-10-27 at 12:02 -0300, Arnaldo Carvalho de Melo wrote: > [..] > > > > The first su

Re: [PATCH -rt] Revert "net: use synchronize_rcu_expedited()"

2015-10-28 Thread Josh Cartwright
On Tue, Oct 27, 2015 at 04:15:59PM -0700, Paul E. McKenney wrote: > On Tue, Oct 27, 2015 at 08:27:53AM -0700, Eric Dumazet wrote: > > On Tue, 2015-10-27 at 12:02 -0300, Arnaldo Carvalho de Melo wrote: [..] > > > The first suggestion, with it disabled by default seems to be the most > > > flexible t

Re: [PATCH -rt] Revert "net: use synchronize_rcu_expedited()"

2015-10-27 Thread Paul E. McKenney
On Tue, Oct 27, 2015 at 08:27:53AM -0700, Eric Dumazet wrote: > On Tue, 2015-10-27 at 12:02 -0300, Arnaldo Carvalho de Melo wrote: > > Em Tue, Oct 27, 2015 at 07:18:01AM -0700, Eric Dumazet escreveu: > > > On Tue, 2015-10-27 at 07:31 -0500, Josh Cartwright wrote: > > > > > > > Okay, yes, I like th

Re: [PATCH -rt] Revert "net: use synchronize_rcu_expedited()"

2015-10-27 Thread Eric Dumazet
On Tue, 2015-10-27 at 12:02 -0300, Arnaldo Carvalho de Melo wrote: > Em Tue, Oct 27, 2015 at 07:18:01AM -0700, Eric Dumazet escreveu: > > On Tue, 2015-10-27 at 07:31 -0500, Josh Cartwright wrote: > > > > > Okay, yes, I like the first suggestion better as well, I've included a > > > patch below tha

Re: [PATCH -rt] Revert "net: use synchronize_rcu_expedited()"

2015-10-27 Thread Arnaldo Carvalho de Melo
Em Tue, Oct 27, 2015 at 07:18:01AM -0700, Eric Dumazet escreveu: > On Tue, 2015-10-27 at 07:31 -0500, Josh Cartwright wrote: > > > Okay, yes, I like the first suggestion better as well, I've included a > > patch below that does just that. I hope you don't mind me turning it > > into a Suggested-b

Re: [PATCH -rt] Revert "net: use synchronize_rcu_expedited()"

2015-10-27 Thread Eric Dumazet
On Tue, 2015-10-27 at 07:31 -0500, Josh Cartwright wrote: > Okay, yes, I like the first suggestion better as well, I've included a > patch below that does just that. I hope you don't mind me turning it > into a Suggested-by :). > > Thanks for taking a look! > Josh > @@ -6969,7 +6969,7 @@ EXP

Re: [PATCH -rt] Revert "net: use synchronize_rcu_expedited()"

2015-10-27 Thread Josh Cartwright
On Mon, Oct 26, 2015 at 05:44:22PM -0700, Paul E. McKenney wrote: > On Mon, Oct 26, 2015 at 02:14:55PM -0500, Josh Cartwright wrote: > > This reverts commit be3fc413da9eb17cce0991f214ab019d16c88c41. > > > > While the use of synchronize_rcu_expedited() might make > > synchronize_net() "faster", it

Re: [PATCH -rt] Revert "net: use synchronize_rcu_expedited()"

2015-10-26 Thread Paul E. McKenney
On Mon, Oct 26, 2015 at 02:14:55PM -0500, Josh Cartwright wrote: > This reverts commit be3fc413da9eb17cce0991f214ab019d16c88c41. > > While the use of synchronize_rcu_expedited() might make > synchronize_net() "faster", it does so at significant cost on RT > systems, as expediting a grace period fo

[PATCH -rt] Revert "net: use synchronize_rcu_expedited()"

2015-10-26 Thread Josh Cartwright
This reverts commit be3fc413da9eb17cce0991f214ab019d16c88c41. While the use of synchronize_rcu_expedited() might make synchronize_net() "faster", it does so at significant cost on RT systems, as expediting a grace period forcibly preempts any high-priority RT tasks (via the stop_machine() mechanis