From ee9c578527a93c66becb526c4a122c5358a959c5 Mon Sep 17 00:00:00 2001 From: Russell King Date: Sun, 20 Apr 2008 13:59:33 +0100 Subject: dyntick: Remove last reminants of dyntick support Remove the last reminants of dyntick support from the generic kernel. Signed-off-by: Russell King --- kernel/hrtimer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/hrtimer.c') diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index 421be5fe5cc7..543d9ca9b4f4 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -1078,7 +1078,7 @@ ktime_t hrtimer_get_remaining(const struct hrtimer *timer) } EXPORT_SYMBOL_GPL(hrtimer_get_remaining); -#if defined(CONFIG_NO_IDLE_HZ) || defined(CONFIG_NO_HZ) +#ifdef CONFIG_NO_HZ /** * hrtimer_get_next_event - get the time until next expiry event * -- cgit v1.3-18-gd494 From 962cf36c5bf6d2840b8d66ee9a606fae2f540bbd Mon Sep 17 00:00:00 2001 From: "Carlos R. Mafra" Date: Thu, 15 May 2008 11:15:37 -0300 Subject: Remove argument from open_softirq which is always NULL As git-grep shows, open_softirq() is always called with the last argument being NULL block/blk-core.c: open_softirq(BLOCK_SOFTIRQ, blk_done_softirq, NULL); kernel/hrtimer.c: open_softirq(HRTIMER_SOFTIRQ, run_hrtimer_softirq, NULL); kernel/rcuclassic.c: open_softirq(RCU_SOFTIRQ, rcu_process_callbacks, NULL); kernel/rcupreempt.c: open_softirq(RCU_SOFTIRQ, rcu_process_callbacks, NULL); kernel/sched.c: open_softirq(SCHED_SOFTIRQ, run_rebalance_domains, NULL); kernel/softirq.c: open_softirq(TASKLET_SOFTIRQ, tasklet_action, NULL); kernel/softirq.c: open_softirq(HI_SOFTIRQ, tasklet_hi_action, NULL); kernel/timer.c: open_softirq(TIMER_SOFTIRQ, run_timer_softirq, NULL); net/core/dev.c: open_softirq(NET_TX_SOFTIRQ, net_tx_action, NULL); net/core/dev.c: open_softirq(NET_RX_SOFTIRQ, net_rx_action, NULL); This observation has already been made by Matthew Wilcox in June 2002 (http://www.cs.helsinki.fi/linux/linux-kernel/2002-25/0687.html) "I notice that none of the current softirq routines use the data element passed to them." and the situation hasn't changed since them. So it appears we can safely remove that extra argument to save 128 (54) bytes of kernel data (text). Signed-off-by: Carlos R. Mafra Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- block/blk-core.c | 2 +- include/linux/interrupt.h | 3 +-- kernel/hrtimer.c | 2 +- kernel/rcuclassic.c | 2 +- kernel/rcupreempt.c | 2 +- kernel/sched.c | 2 +- kernel/softirq.c | 7 +++---- kernel/timer.c | 2 +- net/core/dev.c | 4 ++-- 9 files changed, 12 insertions(+), 14 deletions(-) (limited to 'kernel/hrtimer.c') diff --git a/block/blk-core.c b/block/blk-core.c index 6a9cc0d22a61..75fdc65136e8 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -2048,7 +2048,7 @@ int __init blk_dev_init(void) for_each_possible_cpu(i) INIT_LIST_HEAD(&per_cpu(blk_cpu_done, i)); - open_softirq(BLOCK_SOFTIRQ, blk_done_softirq, NULL); + open_softirq(BLOCK_SOFTIRQ, blk_done_softirq); register_hotcpu_notifier(&blk_cpu_notifier); return 0; diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index f1fc7470d26c..a86186dd0474 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -285,12 +285,11 @@ enum struct softirq_action { void (*action)(struct softirq_action *); - void *data; }; asmlinkage void do_softirq(void); asmlinkage void __do_softirq(void); -extern void open_softirq(int nr, void (*action)(struct softirq_action*), void *data); +extern void open_softirq(int nr, void (*action)(struct softirq_action *)); extern void softirq_init(void); #define __raise_softirq_irqoff(nr) do { or_softirq_pending(1UL << (nr)); } while (0) extern void raise_softirq_irqoff(unsigned int nr); diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index 421be5fe5cc7..861b4088092a 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -1669,7 +1669,7 @@ void __init hrtimers_init(void) (void *)(long)smp_processor_id()); register_cpu_notifier(&hrtimers_nb); #ifdef CONFIG_HIGH_RES_TIMERS - open_softirq(HRTIMER_SOFTIRQ, run_hrtimer_softirq, NULL); + open_softirq(HRTIMER_SOFTIRQ, run_hrtimer_softirq); #endif } diff --git a/kernel/rcuclassic.c b/kernel/rcuclassic.c index f4ffbd0f306f..f6e01f3ae9c6 100644 --- a/kernel/rcuclassic.c +++ b/kernel/rcuclassic.c @@ -529,7 +529,7 @@ static void __cpuinit rcu_online_cpu(int cpu) rcu_init_percpu_data(cpu, &rcu_ctrlblk, rdp); rcu_init_percpu_data(cpu, &rcu_bh_ctrlblk, bh_rdp); - open_softirq(RCU_SOFTIRQ, rcu_process_callbacks, NULL); + open_softirq(RCU_SOFTIRQ, rcu_process_callbacks); } static int __cpuinit rcu_cpu_notify(struct notifier_block *self, diff --git a/kernel/rcupreempt.c b/kernel/rcupreempt.c index e1cdf196a515..9dd827db359f 100644 --- a/kernel/rcupreempt.c +++ b/kernel/rcupreempt.c @@ -1125,7 +1125,7 @@ void __init __rcu_init(void) for_each_online_cpu(cpu) rcu_cpu_notify(&rcu_nb, CPU_UP_PREPARE, (void *)(long) cpu); - open_softirq(RCU_SOFTIRQ, rcu_process_callbacks, NULL); + open_softirq(RCU_SOFTIRQ, rcu_process_callbacks); } /* diff --git a/kernel/sched.c b/kernel/sched.c index cfa222a91539..56ea3a203a5a 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -8154,7 +8154,7 @@ void __init sched_init(void) #endif #ifdef CONFIG_SMP - open_softirq(SCHED_SOFTIRQ, run_rebalance_domains, NULL); + open_softirq(SCHED_SOFTIRQ, run_rebalance_domains); #endif #ifdef CONFIG_RT_MUTEXES diff --git a/kernel/softirq.c b/kernel/softirq.c index 36e061740047..059256874e9b 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -347,9 +347,8 @@ void raise_softirq(unsigned int nr) local_irq_restore(flags); } -void open_softirq(int nr, void (*action)(struct softirq_action*), void *data) +void open_softirq(int nr, void (*action)(struct softirq_action *)) { - softirq_vec[nr].data = data; softirq_vec[nr].action = action; } @@ -503,8 +502,8 @@ void __init softirq_init(void) &per_cpu(tasklet_hi_vec, cpu).head; } - open_softirq(TASKLET_SOFTIRQ, tasklet_action, NULL); - open_softirq(HI_SOFTIRQ, tasklet_hi_action, NULL); + open_softirq(TASKLET_SOFTIRQ, tasklet_action); + open_softirq(HI_SOFTIRQ, tasklet_hi_action); } static int ksoftirqd(void * __bind_cpu) diff --git a/kernel/timer.c b/kernel/timer.c index ceacc6626572..b4da888497fa 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -1502,7 +1502,7 @@ void __init init_timers(void) BUG_ON(err == NOTIFY_BAD); register_cpu_notifier(&timers_nb); - open_softirq(TIMER_SOFTIRQ, run_timer_softirq, NULL); + open_softirq(TIMER_SOFTIRQ, run_timer_softirq); } /** diff --git a/net/core/dev.c b/net/core/dev.c index 582963077877..cf0e16731dc7 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4563,8 +4563,8 @@ static int __init net_dev_init(void) dev_boot_phase = 0; - open_softirq(NET_TX_SOFTIRQ, net_tx_action, NULL); - open_softirq(NET_RX_SOFTIRQ, net_rx_action, NULL); + open_softirq(NET_TX_SOFTIRQ, net_tx_action); + open_softirq(NET_RX_SOFTIRQ, net_rx_action); hotcpu_notifier(dev_cpu_callback, 0); dst_init(); -- cgit v1.3-18-gd494 From d031476408ae0f5196e3c579f519dfdefb099b67 Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Fri, 23 May 2008 14:41:19 +0100 Subject: hrtimer: remove warning in hres_timers_resume hres_timers_resume() warns if there appears to be more than one cpu online. This warning makes sense when the suspend/resume mechanism offlines all cpus but one during the suspend/resume process. However, Xen suspend does not need to offline the other cpus; it merely keeps them tied up in stop_machine() while the virtual machine is suspended. The warning hres_timers_resume issues is therefore spurious. Signed-off-by: Jeremy Fitzhardinge Cc: xen-devel Cc: "Rafael J. Wysocki" Signed-off-by: Thomas Gleixner --- kernel/hrtimer.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'kernel/hrtimer.c') diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index 421be5fe5cc7..493c4b8b8cba 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -632,8 +632,6 @@ void clock_was_set(void) */ void hres_timers_resume(void) { - WARN_ON_ONCE(num_online_cpus() > 1); - /* Retrigger the CPU local events: */ retrigger_next_event(NULL); } -- cgit v1.3-18-gd494 From 900cfa46191a7d87cf1891924cb90499287fd235 Mon Sep 17 00:00:00 2001 From: "Carlos R. Mafra" Date: Thu, 22 May 2008 19:25:11 -0300 Subject: hrtimer: Remove unused variables in ktime_divns() The variables dns and inc are not used, remove them. Signed-off-by: Carlos R. Mafra Cc: tglx@linutronix.de Signed-off-by: Thomas Gleixner --- kernel/hrtimer.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'kernel/hrtimer.c') diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index 493c4b8b8cba..635739d219da 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -300,11 +300,10 @@ EXPORT_SYMBOL_GPL(ktime_sub_ns); */ u64 ktime_divns(const ktime_t kt, s64 div) { - u64 dclc, inc, dns; + u64 dclc; int sft = 0; - dclc = dns = ktime_to_ns(kt); - inc = div; + dclc = ktime_to_ns(kt); /* Make sure the divisor is less than 2^32: */ while (div >> 32) { sft++; -- cgit v1.3-18-gd494 From ee3ece830f6db9837f7ac67008f532a8c1e755f4 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 3 Jul 2008 14:31:26 -0400 Subject: hrtimer: prevent migration for raising softirq Due to a possible deadlock, the waking of the softirq was pushed outside of the hrtimer base locks. See commit 0c96c5979a522c3323c30a078a70120e29b5bdbc Unfortunately this allows the task to migrate after setting up the softirq and raising it. Since softirqs run a queue that is per-cpu we may raise the softirq on the wrong CPU and this will keep the queued softirq task from running. To solve this issue, this patch disables preemption around the releasing of the hrtimer lock and raising of the softirq. Signed-off-by: Steven Rostedt Signed-off-by: Linus Torvalds --- kernel/hrtimer.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'kernel/hrtimer.c') diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index 421be5fe5cc7..ab80515008f4 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -1003,10 +1003,18 @@ hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode) */ raise = timer->state == HRTIMER_STATE_PENDING; + /* + * We use preempt_disable to prevent this task from migrating after + * setting up the softirq and raising it. Otherwise, if me migrate + * we will raise the softirq on the wrong CPU. + */ + preempt_disable(); + unlock_hrtimer_base(timer, &flags); if (raise) hrtimer_raise_softirq(); + preempt_enable(); return ret; } -- cgit v1.3-18-gd494