From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932156Ab3BGPrW (ORCPT ); Thu, 7 Feb 2013 10:47:22 -0500 Received: from mx1.redhat.com ([209.132.183.28]:48586 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754629Ab3BGPrQ (ORCPT ); Thu, 7 Feb 2013 10:47:16 -0500 Date: Thu, 7 Feb 2013 09:47:04 -0600 From: Clark Williams To: Ingo Molnar Cc: Peter Zijlstra , Thomas Gleixner , Steven Rostedt , Ingo Molnar , LKML Subject: [PATCH 2/3] sched/rt: add a tuning knob to allow changing SCHED_RR timeslice Message-ID: <20130207094704.13751796@riff.lan> Organization: Red Hat, Inc Mime-Version: 1.0 Content-Type: multipart/signed; micalg=PGP-SHA1; boundary="Sig_/Iy9_9oopTN6Q=ZXPMloHTkv"; protocol="application/pgp-signature" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --Sig_/Iy9_9oopTN6Q=ZXPMloHTkv Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable Add a /proc/sys/kernel scheduler knob named sched_rr_timeslice_ms that allows global changing of the SCHED_RR timeslice value. User visable value is in milliseconds but is stored as jiffies. Setting to 0 (zero) resets to the default (currently 100ms). Signed-off-by: Clark Williams --- include/linux/sched/sysctl.h | 15 ++++++++++++++- kernel/sched/core.c | 19 +++++++++++++++++++ kernel/sched/rt.c | 6 ++++-- kernel/sysctl.c | 7 +++++++ 4 files changed, 44 insertions(+), 3 deletions(-) diff --git a/include/linux/sched/sysctl.h b/include/linux/sched/sysctl.h index bac914e..d2bb0ae 100644 --- a/include/linux/sched/sysctl.h +++ b/include/linux/sched/sysctl.h @@ -73,6 +73,13 @@ static inline unsigned int get_sysctl_timer_migration(vo= id) return 1; } #endif + +/* + * control realtime throttling: + * + * /proc/sys/kernel/sched_rt_period_us + * /proc/sys/kernel/sched_rt_runtime_us + */ extern unsigned int sysctl_sched_rt_period; extern int sysctl_sched_rt_runtime; =20 @@ -90,7 +97,13 @@ extern unsigned int sysctl_sched_autogroup_enabled; */ #define RR_TIMESLICE (100 * HZ / 1000) =20 -int sched_rt_handler(struct ctl_table *table, int write, +extern int sched_rr_timeslice; + +extern int sched_rr_handler(struct ctl_table *table, int write, + void __user *buffer, size_t *lenp, + loff_t *ppos); + +extern int sched_rt_handler(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos); =20 diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 26058d0..1c39c33 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -7508,6 +7508,25 @@ static int sched_rt_global_constraints(void) } #endif /* CONFIG_RT_GROUP_SCHED */ =20 +int sched_rr_handler(struct ctl_table *table, int write, + void __user *buffer, size_t *lenp, + loff_t *ppos) +{ + int ret; + static DEFINE_MUTEX(mutex); + + mutex_lock(&mutex); + ret =3D proc_dointvec(table, write, buffer, lenp, ppos); + /* make sure that internally we keep jiffies */ + /* also, writing zero resets timeslice to default */ + if (!ret && write) { + sched_rr_timeslice =3D sched_rr_timeslice <=3D 0 ? + RR_TIMESLICE : msecs_to_jiffies(sched_rr_timeslice); + } + mutex_unlock(&mutex); + return ret; +} + int sched_rt_handler(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index 839718d..127a2c4 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -7,6 +7,8 @@ =20 #include =20 +int sched_rr_timeslice =3D RR_TIMESLICE; + static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun= ); =20 struct rt_bandwidth def_rt_bandwidth; @@ -2016,7 +2018,7 @@ static void task_tick_rt(struct rq *rq, struct task_s= truct *p, int queued) if (--p->rt.time_slice) return; =20 - p->rt.time_slice =3D RR_TIMESLICE; + p->rt.time_slice =3D sched_rr_timeslice; =20 /* * Requeue to the end of queue if we (and all of our ancestors) are the @@ -2047,7 +2049,7 @@ static unsigned int get_rr_interval_rt(struct rq *rq,= struct task_struct *task) * Time slice is 0 for SCHED_FIFO tasks */ if (task->policy =3D=3D SCHED_RR) - return RR_TIMESLICE; + return sched_rr_timeslice; else return 0; } diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 7357e23..4fc9be9 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -404,6 +404,13 @@ static struct ctl_table kern_table[] =3D { .mode =3D 0644, .proc_handler =3D sched_rt_handler, }, + { + .procname =3D "sched_rr_timeslice_ms", + .data =3D &sched_rr_timeslice, + .maxlen =3D sizeof(int), + .mode =3D 0644, + .proc_handler =3D sched_rr_handler, + }, #ifdef CONFIG_SCHED_AUTOGROUP { .procname =3D "sched_autogroup_enabled", --=20 1.8.1 --Sig_/Iy9_9oopTN6Q=ZXPMloHTkv Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (GNU/Linux) iEYEARECAAYFAlETzHgACgkQHyuj/+TTEp09AgCeIQgGwjU3dX2Kxszv/gMEotpt 8xUAoL0ODwNr20/qG0aIp5xvDuonIWwY =pflf -----END PGP SIGNATURE----- --Sig_/Iy9_9oopTN6Q=ZXPMloHTkv--