Re: [PATCH 1/1] rcu/sync: remove un-used rcu_sync_enter_start function
From: Paul E. McKenney
Date: Tue Jan 16 2024 - 14:10:44 EST
On Tue, Jan 16, 2024 at 07:10:59PM +0100, Oleg Nesterov wrote:
> On 01/16, Paul E. McKenney wrote:
> >
> > On Thu, Jan 11, 2024 at 02:57:22PM +0530, Onkarnarth wrote:
> > > From: Onkarnath <onkarnath.1@xxxxxxxxxxx>
> > >
> > > With commit '6a010a49b63a ("cgroup: Make !percpu threadgroup_rwsem
> > > operations optional")' usage of rcu_sync_enter_start is removed.
> > >
> > > So this function can also be removed.
> > >
> > > Signed-off-by: Onkarnath <onkarnath.1@xxxxxxxxxxx>
> > > Signed-off-by: Maninder Singh <maninder1.s@xxxxxxxxxxx>
>
> Acked-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Queued, thank you all!
> For the record, this was already discussed, see
> https://lore.kernel.org/all/20220725121208.GB28662@xxxxxxxxxx/
I am clearly not keeping up. ;-)
> Note also the patch in this message, __rcu_sync_enter(wait => false)
> is a better alternative if someone needs rcu_sync_enter_start() again.
Good to know! I added this to the commit log, so please let me know
if this is in any way inappropriate:
------------------------------------------------------------------------
In the words of Oleg Nesterov:
__rcu_sync_enter(wait => false) is a better alternative if
someone needs rcu_sync_enter_start() again.
Link: https://lore.kernel.org/all/20220725121208.GB28662@xxxxxxxxxx/
------------------------------------------------------------------------
> This patch probably makes sense anyway. Not only cgroup_favor_dynmods()
> can use __rcu_sync_enter(), freeze_super() can use it too to avoid
> 3 synchronize_rcu()'s in a row.
Thank you for the background information, much appreciated!
Thanx, Paul