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authorTiezhu Yang <yangtiezhu@loongson.cn>2023-02-25 10:52:56 +0300
committerHuacai Chen <chenhuacai@loongson.cn>2023-02-25 17:12:16 +0300
commitbb7a78e343468873bf00b2b181fcfd3c02d8cb56 (patch)
tree76350dd5fda6a12ee77d014d79d6b0bc5ad3b1e5 /arch/loongarch
parentfd200632d09dcea9fd67714241155b7635505cd6 (diff)
downloadlinux-bb7a78e343468873bf00b2b181fcfd3c02d8cb56.tar.xz
LoongArch: Only call get_timer_irq() once in constant_clockevent_init()
Under CONFIG_DEBUG_ATOMIC_SLEEP=y and CONFIG_DEBUG_PREEMPT=y, we can see the following messages on LoongArch, this is because using might_sleep() in preemption disable context. [ 0.001127] smp: Bringing up secondary CPUs ... [ 0.001222] Booting CPU#1... [ 0.001244] 64-bit Loongson Processor probed (LA464 Core) [ 0.001247] CPU1 revision is: 0014c012 (Loongson-64bit) [ 0.001250] FPU1 revision is: 00000000 [ 0.001252] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:283 [ 0.001255] in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 0, name: swapper/1 [ 0.001257] preempt_count: 1, expected: 0 [ 0.001258] RCU nest depth: 0, expected: 0 [ 0.001259] Preemption disabled at: [ 0.001261] [<9000000000223800>] arch_dup_task_struct+0x20/0x110 [ 0.001272] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.2.0-rc7+ #43 [ 0.001275] Hardware name: Loongson Loongson-3A5000-7A1000-1w-A2101/Loongson-LS3A5000-7A1000-1w-A2101, BIOS vUDK2018-LoongArch-V4.0.05132-beta10 12/13/202 [ 0.001277] Stack : 0072617764726148 0000000000000000 9000000000222f1c 90000001001e0000 [ 0.001286] 90000001001e3be0 90000001001e3be8 0000000000000000 0000000000000000 [ 0.001292] 90000001001e3be8 0000000000000040 90000001001e3cb8 90000001001e3a50 [ 0.001297] 9000000001642000 90000001001e3be8 be694d10ce4139dd 9000000100174500 [ 0.001303] 0000000000000001 0000000000000001 00000000ffffe0a2 0000000000000020 [ 0.001309] 000000000000002f 9000000001354116 00000000056b0000 ffffffffffffffff [ 0.001314] 0000000000000000 0000000000000000 90000000014f6e90 9000000001642000 [ 0.001320] 900000000022b69c 0000000000000001 0000000000000000 9000000001736a90 [ 0.001325] 9000000100038000 0000000000000000 9000000000222f34 0000000000000000 [ 0.001331] 00000000000000b0 0000000000000004 0000000000000000 0000000000070000 [ 0.001337] ... [ 0.001339] Call Trace: [ 0.001342] [<9000000000222f34>] show_stack+0x5c/0x180 [ 0.001346] [<90000000010bdd80>] dump_stack_lvl+0x60/0x88 [ 0.001352] [<9000000000266418>] __might_resched+0x180/0x1cc [ 0.001356] [<90000000010c742c>] mutex_lock+0x20/0x64 [ 0.001359] [<90000000002a8ccc>] irq_find_matching_fwspec+0x48/0x124 [ 0.001364] [<90000000002259c4>] constant_clockevent_init+0x68/0x204 [ 0.001368] [<900000000022acf4>] start_secondary+0x40/0xa8 [ 0.001371] [<90000000010c0124>] smpboot_entry+0x60/0x64 Here are the complete call chains: smpboot_entry() start_secondary() constant_clockevent_init() get_timer_irq() irq_find_matching_fwnode() irq_find_matching_fwspec() mutex_lock() might_sleep() __might_sleep() __might_resched() In order to avoid the above issue, we should break the call chains, using timer_irq_installed variable as check condition to only call get_timer_irq() once in constant_clockevent_init() is a simple and proper way. Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Diffstat (limited to 'arch/loongarch')
-rw-r--r--arch/loongarch/kernel/time.c11
1 files changed, 6 insertions, 5 deletions
diff --git a/arch/loongarch/kernel/time.c b/arch/loongarch/kernel/time.c
index a6576dea590c..4351f69d9950 100644
--- a/arch/loongarch/kernel/time.c
+++ b/arch/loongarch/kernel/time.c
@@ -140,16 +140,17 @@ static int get_timer_irq(void)
int constant_clockevent_init(void)
{
- int irq;
unsigned int cpu = smp_processor_id();
unsigned long min_delta = 0x600;
unsigned long max_delta = (1UL << 48) - 1;
struct clock_event_device *cd;
- static int timer_irq_installed = 0;
+ static int irq = 0, timer_irq_installed = 0;
- irq = get_timer_irq();
- if (irq < 0)
- pr_err("Failed to map irq %d (timer)\n", irq);
+ if (!timer_irq_installed) {
+ irq = get_timer_irq();
+ if (irq < 0)
+ pr_err("Failed to map irq %d (timer)\n", irq);
+ }
cd = &per_cpu(constant_clockevent_device, cpu);