From c85867b46de81ad6b5de153743cf4cfc42814d3b Mon Sep 17 00:00:00 2001 Message-Id: In-Reply-To: <5b5a156f9808b1acf1205606e03da117214549ea.1601675151.git.zanussi@kernel.org> References: <5b5a156f9808b1acf1205606e03da117214549ea.1601675151.git.zanussi@kernel.org> From: Yang Shi Date: Mon, 16 Sep 2013 14:09:19 -0700 Subject: [PATCH 102/333] hrtimer: Move schedule_work call to helper thread Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.148-rt64.tar.xz When run ltp leapsec_timer test, the following call trace is caught: BUG: sleeping function called from invalid context at kernel/rtmutex.c:659 in_atomic(): 1, irqs_disabled(): 1, pid: 0, name: swapper/1 Preemption disabled at:[] cpu_startup_entry+0x133/0x310 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 3.10.10-rt3 #2 Hardware name: Intel Corporation Calpella platform/MATXM-CORE-411-B, BIOS 4.6.3 08/18/2010 ffffffff81c2f800 ffff880076843e40 ffffffff8169918d ffff880076843e58 ffffffff8106db31 ffff88007684b4a0 ffff880076843e70 ffffffff8169d9c0 ffff88007684b4a0 ffff880076843eb0 ffffffff81059da1 0000001876851200 Call Trace: [] dump_stack+0x19/0x1b [] __might_sleep+0xf1/0x170 [] rt_spin_lock+0x20/0x50 [] queue_work_on+0x61/0x100 [] clock_was_set_delayed+0x21/0x30 [] do_timer+0x40e/0x660 [] tick_do_update_jiffies64+0xf7/0x140 [] tick_check_idle+0x92/0xc0 [] irq_enter+0x57/0x70 [] smp_apic_timer_interrupt+0x3e/0x9b [] apic_timer_interrupt+0x6a/0x70 [] ? cpuidle_enter_state+0x4c/0xc0 [] cpuidle_idle_call+0xd8/0x2d0 [] arch_cpu_idle+0xe/0x30 [] cpu_startup_entry+0x19e/0x310 [] start_secondary+0x1ad/0x1b0 The clock_was_set_delayed is called in hard IRQ handler (timer interrupt), which calls schedule_work. Under PREEMPT_RT_FULL, schedule_work calls spinlocks which could sleep, so it's not safe to call schedule_work in interrupt context. Reference upstream commit b68d61c705ef02384c0538b8d9374545097899ca (rt,ntp: Move call to schedule_delayed_work() to helper thread) from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git, which makes a similar change. Signed-off-by: Yang Shi [bigeasy: use swork_queue() instead a helper thread] Signed-off-by: Sebastian Andrzej Siewior --- kernel/time/hrtimer.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index 1fd5ec39e7f4..9f3412acdb16 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -730,6 +730,29 @@ static void hrtimer_switch_to_hres(void) retrigger_next_event(NULL); } +#ifdef CONFIG_PREEMPT_RT_FULL + +static struct swork_event clock_set_delay_work; + +static void run_clock_set_delay(struct swork_event *event) +{ + clock_was_set(); +} + +void clock_was_set_delayed(void) +{ + swork_queue(&clock_set_delay_work); +} + +static __init int create_clock_set_delay_thread(void) +{ + WARN_ON(swork_get()); + INIT_SWORK(&clock_set_delay_work, run_clock_set_delay); + return 0; +} +early_initcall(create_clock_set_delay_thread); +#else /* PREEMPT_RT_FULL */ + static void clock_was_set_work(struct work_struct *work) { clock_was_set(); @@ -745,6 +768,7 @@ void clock_was_set_delayed(void) { schedule_work(&hrtimer_work); } +#endif #else -- 2.17.1