Messages in this thread | | | Date | Tue, 27 Oct 2015 12:02:51 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH -rt] Revert "net: use synchronize_rcu_expedited()" |
| |
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-by :). > > > > Thanks for taking a look! > > Josh > > > > @@ -6969,7 +6969,7 @@ EXPORT_SYMBOL(free_netdev); > > void synchronize_net(void) > > { > > might_sleep(); > > - if (rtnl_is_locked()) > > + if (rtnl_is_locked() && !IS_ENABLED(CONFIG_PREEMPT_RT_FULL)) > > synchronize_rcu_expedited(); > > else > > synchronize_rcu(); > > No objection from me. Thanks. > > Acked-by: Eric Dumazet <edumazet@google.com>
The first suggestion, with it disabled by default seems to be the most flexible tho, i.e, Paul's original message plus the boot parameter line:
Alternatively, a boot-time option could be used:
int some_rt_boot_parameter = CONFIG_SYNC_NET_DEFAULT;
if (rtnl_is_locked() && !some_rt_boot_parameter) synchronize_rcu_expedited(); else synchronize_rcu();
Then RT oriented kernel .config files would have CONFIG_SYNC_NET_DEFAULT set to 1, while upstream would have this default to 0.
RT oriented kernel users could try using this in some scenarios where networking is not the critical path.
- Arnaldo
| |