From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756118AbbDNVRv (ORCPT ); Tue, 14 Apr 2015 17:17:51 -0400 Received: from www.linutronix.de ([62.245.132.108]:37865 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754795AbbDNVIF (ORCPT ); Tue, 14 Apr 2015 17:08:05 -0400 Message-Id: <20150414203500.645454122@linutronix.de> User-Agent: quilt/0.63-1 Date: Tue, 14 Apr 2015 21:08:27 -0000 From: Thomas Gleixner To: LKML Cc: Peter Zijlstra , Ingo Molnar , Preeti U Murthy , Viresh Kumar , Marcelo Tosatti , Frederic Weisbecker Subject: [patch 02/39] hrtimer: Get rid of the resolution field in hrtimer_clock_base References: <20150414203303.702062272@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Disposition: inline; filename=hrtimer-get-rid-of-resolution.patch X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001,URIBL_BLOCKED=0.001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The field has no value because all clock bases have the same resolution. The resolution only changes when we switch to high resolution timer mode. We can evaluate that from a single static variable as well. In the !HIGHRES case its simply a constant. Export the variable, so we can simplify the usage sites. Signed-off-by: Thomas Gleixner --- include/linux/hrtimer.h | 6 ++++-- kernel/time/hrtimer.c | 26 +++++++++----------------- kernel/time/timer_list.c | 8 ++++---- 3 files changed, 17 insertions(+), 23 deletions(-) Index: tip/include/linux/hrtimer.h =================================================================== --- tip.orig/include/linux/hrtimer.h +++ tip/include/linux/hrtimer.h @@ -137,7 +137,6 @@ struct hrtimer_sleeper { * timer to a base on another cpu. * @clockid: clock id for per_cpu support * @active: red black tree root node for the active timers - * @resolution: the resolution of the clock, in nanoseconds * @get_time: function to retrieve the current time of the clock * @softirq_time: the time when running the hrtimer queue in the softirq * @offset: offset of this clock to the monotonic base @@ -147,7 +146,6 @@ struct hrtimer_clock_base { int index; clockid_t clockid; struct timerqueue_head active; - ktime_t resolution; ktime_t (*get_time)(void); ktime_t softirq_time; ktime_t offset; @@ -295,11 +293,15 @@ extern void hrtimer_peek_ahead_timers(vo extern void clock_was_set_delayed(void); +extern unsigned int hrtimer_resolution; + #else # define MONOTONIC_RES_NSEC LOW_RES_NSEC # define KTIME_MONOTONIC_RES KTIME_LOW_RES +#define hrtimer_resolution LOW_RES_NSEC + static inline void hrtimer_peek_ahead_timers(void) { } /* Index: tip/kernel/time/hrtimer.c =================================================================== --- tip.orig/kernel/time/hrtimer.c +++ tip/kernel/time/hrtimer.c @@ -66,7 +66,6 @@ */ DEFINE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases) = { - .lock = __RAW_SPIN_LOCK_UNLOCKED(hrtimer_bases.lock), .clock_base = { @@ -74,25 +73,21 @@ DEFINE_PER_CPU(struct hrtimer_cpu_base, .index = HRTIMER_BASE_MONOTONIC, .clockid = CLOCK_MONOTONIC, .get_time = &ktime_get, - .resolution = KTIME_LOW_RES, }, { .index = HRTIMER_BASE_REALTIME, .clockid = CLOCK_REALTIME, .get_time = &ktime_get_real, - .resolution = KTIME_LOW_RES, }, { .index = HRTIMER_BASE_BOOTTIME, .clockid = CLOCK_BOOTTIME, .get_time = &ktime_get_boottime, - .resolution = KTIME_LOW_RES, }, { .index = HRTIMER_BASE_TAI, .clockid = CLOCK_TAI, .get_time = &ktime_get_clocktai, - .resolution = KTIME_LOW_RES, }, } }; @@ -478,6 +473,8 @@ static ktime_t __hrtimer_get_next_event( * High resolution timer enabled ? */ static int hrtimer_hres_enabled __read_mostly = 1; +unsigned int hrtimer_resolution __read_mostly = LOW_RES_NSEC; +EXPORT_SYMBOL_GPL(hrtimer_resolution); /* * Enable / Disable high resolution mode @@ -660,7 +657,7 @@ static void retrigger_next_event(void *a */ static int hrtimer_switch_to_hres(void) { - int i, cpu = smp_processor_id(); + int cpu = smp_processor_id(); struct hrtimer_cpu_base *base = &per_cpu(hrtimer_bases, cpu); unsigned long flags; @@ -676,8 +673,7 @@ static int hrtimer_switch_to_hres(void) return 0; } base->hres_active = 1; - for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) - base->clock_base[i].resolution = KTIME_HIGH_RES; + hrtimer_resolution = HIGH_RES_NSEC; tick_setup_sched_timer(); /* "Retrigger" the interrupt to get things going */ @@ -812,8 +808,8 @@ u64 hrtimer_forward(struct hrtimer *time if (delta.tv64 < 0) return 0; - if (interval.tv64 < timer->base->resolution.tv64) - interval.tv64 = timer->base->resolution.tv64; + if (interval.tv64 < hrtimer_resolution) + interval.tv64 = hrtimer_resolution; if (unlikely(delta.tv64 >= interval.tv64)) { s64 incr = ktime_to_ns(interval); @@ -955,7 +951,7 @@ int __hrtimer_start_range_ns(struct hrti * timeouts. This will go away with the GTOD framework. */ #ifdef CONFIG_TIME_LOW_RES - tim = ktime_add_safe(tim, base->resolution); + tim = ktime_add_safe(tim, ktime_set(0, hrtimer_resolution)); #endif } @@ -1185,12 +1181,8 @@ EXPORT_SYMBOL_GPL(hrtimer_init); */ int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp) { - struct hrtimer_cpu_base *cpu_base; - int base = hrtimer_clockid_to_base(which_clock); - - cpu_base = raw_cpu_ptr(&hrtimer_bases); - *tp = ktime_to_timespec(cpu_base->clock_base[base].resolution); - + tp->tv_sec = 0; + tp->tv_nsec = hrtimer_resolution; return 0; } EXPORT_SYMBOL_GPL(hrtimer_get_res); Index: tip/kernel/time/timer_list.c =================================================================== --- tip.orig/kernel/time/timer_list.c +++ tip/kernel/time/timer_list.c @@ -120,10 +120,10 @@ static void print_base(struct seq_file *m, struct hrtimer_clock_base *base, u64 now) { SEQ_printf(m, " .base: %pK\n", base); - SEQ_printf(m, " .index: %d\n", - base->index); - SEQ_printf(m, " .resolution: %Lu nsecs\n", - (unsigned long long)ktime_to_ns(base->resolution)); + SEQ_printf(m, " .index: %d\n", base->index); + + SEQ_printf(m, " .resolution: %u nsecs\n", (unsigned) hrtimer_resolution); + SEQ_printf(m, " .get_time: "); print_name_offset(m, base->get_time); SEQ_printf(m, "\n");