[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20150513003750.GA1806@lerouge>
Date: Wed, 13 May 2015 02:37:52 +0200
From: Frederic Weisbecker <fweisbec@...il.com>
To: "Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>
Cc: linux-kernel@...r.kernel.org, mingo@...nel.org,
laijs@...fujitsu.com, dipankar@...ibm.com,
akpm@...ux-foundation.org, mathieu.desnoyers@...icios.com,
josh@...htriplett.org, tglx@...utronix.de, peterz@...radead.org,
rostedt@...dmis.org, dhowells@...hat.com, edumazet@...gle.com,
dvhart@...ux.intel.com, oleg@...hat.com, bobby.prani@...il.com
Subject: Re: [PATCH tip/core/rcu 15/24] rcu: Directly drive RCU_USER_QS from
Kconfig
On Tue, May 12, 2015 at 03:30:45PM -0700, Paul E. McKenney wrote:
> From: "Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>
>
> Currently, Kconfig will ask the user whether RCU_USER_QS should be set.
> This is silly because Kconfig already has all the information that it
> needs to set this parameter. This commit therefore directly drives
> the value of RCU_USER_QS via NO_HZ_FULL's "select" statement.
>
> Reported-by: Ingo Molnar <mingo@...nel.org>
> Signed-off-by: Paul E. McKenney <paulmck@...ux.vnet.ibm.com>
> Cc: Frederic Weisbecker <fweisbec@...il.com>
ACK. And we should remove it completely and use NO_HZ_FULL instead.
There won't seem to be more users.
> Reviewed-by: Pranith Kumar <bobby.prani@...il.com>
> ---
> init/Kconfig | 10 +---------
> 1 file changed, 1 insertion(+), 9 deletions(-)
>
> diff --git a/init/Kconfig b/init/Kconfig
> index 73db30a76afa..927210810189 100644
> --- a/init/Kconfig
> +++ b/init/Kconfig
> @@ -529,9 +529,7 @@ config CONTEXT_TRACKING
> bool
>
> config RCU_USER_QS
> - bool "Consider userspace as in RCU extended quiescent state"
> - depends on HAVE_CONTEXT_TRACKING && SMP
> - select CONTEXT_TRACKING
> + bool
> help
> This option sets hooks on kernel / userspace boundaries and
> puts RCU in extended quiescent state when the CPU runs in
> @@ -539,12 +537,6 @@ config RCU_USER_QS
> excluded from the global RCU state machine and thus doesn't
> try to keep the timer tick on for RCU.
>
> - Unless you want to hack and help the development of the full
> - dynticks mode, you shouldn't enable this option. It also
> - adds unnecessary overhead.
> -
> - If unsure say N
> -
> config CONTEXT_TRACKING_FORCE
> bool "Force context tracking"
> depends on CONTEXT_TRACKING
> --
> 1.8.1.5
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists