Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265276AbTF1QNp (ORCPT ); Sat, 28 Jun 2003 12:13:45 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265279AbTF1QNp (ORCPT ); Sat, 28 Jun 2003 12:13:45 -0400 Received: from c17870.thoms1.vic.optusnet.com.au ([210.49.248.224]:59082 "EHLO mail.kolivas.org") by vger.kernel.org with ESMTP id S265276AbTF1QNl (ORCPT ); Sat, 28 Jun 2003 12:13:41 -0400 From: Con Kolivas To: linux kernel mailing list Subject: Re: patch-O1int-0306281420 for 2.5.73 interactivity Date: Sun, 29 Jun 2003 02:30:40 +1000 User-Agent: KMail/1.5.2 Cc: Felipe Alfaro Solana , Mike Galbraith , Zwane Mwaikambo , Martin Schlemmer , Roberto Orenstein References: <200306281516.12975.kernel@kolivas.org> In-Reply-To: <200306281516.12975.kernel@kolivas.org> MIME-Version: 1.0 Content-Type: Multipart/Mixed; boundary="Boundary-00=_wKc/+nWPW032OPm" Message-Id: <200306290230.40059.kernel@kolivas.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6448 Lines: 189 --Boundary-00=_wKc/+nWPW032OPm Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline On Sat, 28 Jun 2003 15:16, Con Kolivas wrote: > For my sins I've included what I thought was necessary for this patch. > > The interactivity for tasks is based on the sleep avg accumulated divided > by the running time of the task. However since the accumulated time is not > linear with time it now works on the premise that running time is an > exponential function entirely. Pat Erley was the genius who implemented > this simple exponential function in surprisingly low overhead integer > maths. > > Also added was some jiffy wrap logic (as if anyone would still be running > my patch in 50 days :P). > > Long sleepers were reclassified as idle according to the new exponential > logic. > > If you test, please note this works better at 1000Hz. > > Attached also is my bastardised version of Ingo's timeslice granularity > patch. This round robins tasks on the active array every 10ms, which > _might_ be detrimental in throughput applications but has not been > benchmarked. However for desktops it does wonders to smoothing out the > jerkiness of X and I highly recommend using this in combination with the > O1int patch. > > This is very close to all the logic I wanted to implement. It might need > more tuning... Note parent penalty, child penalty and exit weight > (uppercase) no longer do anything. > > Please test and comment. > > Con > > P.S. In the words of Zwane - there is always a corner case. Corner case I > think I still need to tackle is the application that spins madly waiting > for it's child to start, and in the process it is the parent that is > starving the child by being higher priority than it. This seems to be a > coding style anomaly brought out by the scheduler. And just for good measure here is the latest with a slight addition that helps X smoothness over time. It gives the sleep_avg a little headroom so it doesn't drop from interactive as easily with bursts of cpu activity. Con --Boundary-00=_wKc/+nWPW032OPm Content-Type: text/x-diff; charset="iso-8859-1"; name="patch-O1int-0306290223" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename="patch-O1int-0306290223" diff -Naurp linux-2.5.73/include/linux/sched.h linux-2.5.73-test/include/linux/sched.h --- linux-2.5.73/include/linux/sched.h 2003-06-26 01:30:42.000000000 +1000 +++ linux-2.5.73-test/include/linux/sched.h 2003-06-28 14:09:08.000000000 +1000 @@ -336,6 +336,7 @@ struct task_struct { prio_array_t *array; unsigned long sleep_avg; + unsigned long avg_start; unsigned long last_run; unsigned long policy; diff -Naurp linux-2.5.73/kernel/fork.c linux-2.5.73-test/kernel/fork.c --- linux-2.5.73/kernel/fork.c 2003-06-26 01:30:42.000000000 +1000 +++ linux-2.5.73-test/kernel/fork.c 2003-06-28 14:09:08.000000000 +1000 @@ -863,6 +863,7 @@ struct task_struct *copy_process(unsigne p->array = NULL; p->lock_depth = -1; /* -1 = no lock */ p->start_time = get_jiffies_64(); + p->avg_start = jiffies; p->security = NULL; retval = -ENOMEM; diff -Naurp linux-2.5.73/kernel/sched.c linux-2.5.73-test/kernel/sched.c --- linux-2.5.73/kernel/sched.c 2003-06-26 01:30:42.000000000 +1000 +++ linux-2.5.73-test/kernel/sched.c 2003-06-28 14:19:03.000000000 +1000 @@ -314,11 +314,29 @@ static inline void enqueue_task(struct t static int effective_prio(task_t *p) { int bonus, prio; + long sleep_period, tau; if (rt_task(p)) return p->prio; - bonus = MAX_USER_PRIO*PRIO_BONUS_RATIO*p->sleep_avg/MAX_SLEEP_AVG/100 - + tau = MAX_SLEEP_AVG; + + sleep_period = jiffies - p->avg_start; + if (sleep_period > MAX_SLEEP_AVG) + sleep_period = MAX_SLEEP_AVG; + else if (!sleep_period) + return p->static_prio; + else { + sleep_period = (sleep_period * + 17 * sleep_period / ((17 * sleep_period / (5 * tau) + 2) * 5 * tau)); + if (!sleep_period) + return p->static_prio; + } + + if (p->sleep_avg > sleep_period) + sleep_period = p->sleep_avg; + + bonus = MAX_USER_PRIO*PRIO_BONUS_RATIO*p->sleep_avg/sleep_period/100 - MAX_USER_PRIO*PRIO_BONUS_RATIO/100/2; prio = p->static_prio - bonus; @@ -349,8 +367,12 @@ static inline void activate_task(task_t long sleep_time = jiffies - p->last_run - 1; if (sleep_time > 0) { - int sleep_avg; + if (sleep_time > HZ){ + p->avg_start = jiffies - HZ; + p->sleep_avg = HZ / 13; + } + else { /* * This code gives a bonus to interactive tasks. * @@ -359,7 +381,7 @@ static inline void activate_task(task_t * spends sleeping, the higher the average gets - and the * higher the priority boost gets as well. */ - sleep_avg = p->sleep_avg + sleep_time; + p->sleep_avg += sleep_time; /* * 'Overflow' bonus ticks go to the waker as well, so the @@ -367,12 +389,14 @@ static inline void activate_task(task_t * boosting tasks that are related to maximum-interactive * tasks. */ - if (sleep_avg > MAX_SLEEP_AVG) - sleep_avg = MAX_SLEEP_AVG; - if (p->sleep_avg != sleep_avg) { - p->sleep_avg = sleep_avg; - p->prio = effective_prio(p); + if (p->sleep_avg > MAX_SLEEP_AVG * 12 / 10) + p->sleep_avg = MAX_SLEEP_AVG * 11 / 10; + } + if (unlikely((jiffies - MAX_SLEEP_AVG) < p->avg_start)){ + p->avg_start = jiffies; + p->sleep_avg = 0; } + p->prio = effective_prio(p); } __activate_task(p, rq); } @@ -549,8 +573,6 @@ void wake_up_forked_process(task_t * p) * and children as well, to keep max-interactive tasks * from forking tasks that are max-interactive. */ - current->sleep_avg = current->sleep_avg * PARENT_PENALTY / 100; - p->sleep_avg = p->sleep_avg * CHILD_PENALTY / 100; p->prio = effective_prio(p); set_task_cpu(p, smp_processor_id()); @@ -586,13 +608,6 @@ void sched_exit(task_t * p) p->parent->time_slice = MAX_TIMESLICE; } local_irq_restore(flags); - /* - * If the child was a (relative-) CPU hog then decrease - * the sleep_avg of the parent as well. - */ - if (p->sleep_avg < p->parent->sleep_avg) - p->parent->sleep_avg = (p->parent->sleep_avg * EXIT_WEIGHT + - p->sleep_avg) / (EXIT_WEIGHT + 1); } /** --Boundary-00=_wKc/+nWPW032OPm-- - 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/