Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754576AbZLIJ7A (ORCPT ); Wed, 9 Dec 2009 04:59:00 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754575AbZLIJ5s (ORCPT ); Wed, 9 Dec 2009 04:57:48 -0500 Received: from hera.kernel.org ([140.211.167.34]:45771 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754556AbZLIJ5o (ORCPT ); Wed, 9 Dec 2009 04:57:44 -0500 Date: Wed, 9 Dec 2009 09:56:02 GMT From: tip-bot for Christian Ehrhardt Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, a.p.zijlstra@chello.nl, ehrhardt@linux.vnet.ibm.com, tglx@linutronix.de, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, a.p.zijlstra@chello.nl, ehrhardt@linux.vnet.ibm.com, tglx@linutronix.de, mingo@elte.hu In-Reply-To: <1259579808-11357-2-git-send-email-ehrhardt@linux.vnet.ibm.com> References: <1259579808-11357-2-git-send-email-ehrhardt@linux.vnet.ibm.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:sched/urgent] sched: Fix missing sched tunable recalculation on cpu add/remove Message-ID: Git-Commit-ID: 0bcdcf28c979869f44e05121b96ff2cfb05bd8e6 X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4541 Lines: 138 Commit-ID: 0bcdcf28c979869f44e05121b96ff2cfb05bd8e6 Gitweb: http://git.kernel.org/tip/0bcdcf28c979869f44e05121b96ff2cfb05bd8e6 Author: Christian Ehrhardt AuthorDate: Mon, 30 Nov 2009 12:16:46 +0100 Committer: Ingo Molnar CommitDate: Wed, 9 Dec 2009 10:03:58 +0100 sched: Fix missing sched tunable recalculation on cpu add/remove Based on Peter Zijlstras patch suggestion this enables recalculation of the scheduler tunables in response of a change in the number of cpus. It also adds a max of eight cpus that are considered in that scaling. Signed-off-by: Christian Ehrhardt Signed-off-by: Peter Zijlstra LKML-Reference: <1259579808-11357-2-git-send-email-ehrhardt@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar --- kernel/sched.c | 29 ++++++++++++++++------------- kernel/sched_fair.c | 16 ++++++++++++++++ 2 files changed, 32 insertions(+), 13 deletions(-) diff --git a/kernel/sched.c b/kernel/sched.c index 3878f50..b54ecf8 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -814,6 +814,7 @@ const_debug unsigned int sysctl_sched_nr_migrate = 32; * default: 0.25ms */ unsigned int sysctl_sched_shares_ratelimit = 250000; +unsigned int normalized_sysctl_sched_shares_ratelimit = 250000; /* * Inject some fuzzyness into changing the per-cpu group shares @@ -1814,6 +1815,7 @@ static void cfs_rq_set_shares(struct cfs_rq *cfs_rq, unsigned long shares) #endif static void calc_load_account_active(struct rq *this_rq); +static void update_sysctl(void); static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) { @@ -7028,22 +7030,23 @@ cpumask_var_t nohz_cpu_mask; * * This idea comes from the SD scheduler of Con Kolivas: */ -static inline void sched_init_granularity(void) +static void update_sysctl(void) { - unsigned int factor = 1 + ilog2(num_online_cpus()); - const unsigned long limit = 200000000; - - sysctl_sched_min_granularity *= factor; - if (sysctl_sched_min_granularity > limit) - sysctl_sched_min_granularity = limit; - - sysctl_sched_latency *= factor; - if (sysctl_sched_latency > limit) - sysctl_sched_latency = limit; + unsigned int cpus = min(num_online_cpus(), 8U); + unsigned int factor = 1 + ilog2(cpus); - sysctl_sched_wakeup_granularity *= factor; +#define SET_SYSCTL(name) \ + (sysctl_##name = (factor) * normalized_sysctl_##name) + SET_SYSCTL(sched_min_granularity); + SET_SYSCTL(sched_latency); + SET_SYSCTL(sched_wakeup_granularity); + SET_SYSCTL(sched_shares_ratelimit); +#undef SET_SYSCTL +} - sysctl_sched_shares_ratelimit *= factor; +static inline void sched_init_granularity(void) +{ + update_sysctl(); } #ifdef CONFIG_SMP diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index c163a28..71b3458 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -35,12 +35,14 @@ * run vmstat and monitor the context-switches (cs) field) */ unsigned int sysctl_sched_latency = 5000000ULL; +unsigned int normalized_sysctl_sched_latency = 5000000ULL; /* * Minimal preemption granularity for CPU-bound tasks: * (default: 1 msec * (1 + ilog(ncpus)), units: nanoseconds) */ unsigned int sysctl_sched_min_granularity = 1000000ULL; +unsigned int normalized_sysctl_sched_min_granularity = 1000000ULL; /* * is kept at sysctl_sched_latency / sysctl_sched_min_granularity @@ -70,6 +72,7 @@ unsigned int __read_mostly sysctl_sched_compat_yield; * have immediate wakeup/sleep latencies. */ unsigned int sysctl_sched_wakeup_granularity = 1000000UL; +unsigned int normalized_sysctl_sched_wakeup_granularity = 1000000UL; const_debug unsigned int sysctl_sched_migration_cost = 500000UL; @@ -1890,6 +1893,17 @@ move_one_task_fair(struct rq *this_rq, int this_cpu, struct rq *busiest, return 0; } + +static void rq_online_fair(struct rq *rq) +{ + update_sysctl(); +} + +static void rq_offline_fair(struct rq *rq) +{ + update_sysctl(); +} + #endif /* CONFIG_SMP */ /* @@ -2035,6 +2049,8 @@ static const struct sched_class fair_sched_class = { .load_balance = load_balance_fair, .move_one_task = move_one_task_fair, + .rq_online = rq_online_fair, + .rq_offline = rq_offline_fair, #endif .set_curr_task = set_curr_task_fair, -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/