Commit ab63a633 authored Oct 25, 2007 by Peter Zijlstra

sched: fix unconditional irq lock



Lockdep noticed that this lock can also be taken from hardirq context, and can
thus not unconditionally disable/enable irqs.

 WARNING: at kernel/lockdep.c:2033 trace_hardirqs_on()
  [show_trace_log_lvl+26/48] show_trace_log_lvl+0x1a/0x30
  [show_trace+18/32] show_trace+0x12/0x20
  [dump_stack+22/32] dump_stack+0x16/0x20
  [trace_hardirqs_on+405/416] trace_hardirqs_on+0x195/0x1a0
  [_read_unlock_irq+34/48] _read_unlock_irq+0x22/0x30
  [sched_debug_show+2615/4224] sched_debug_show+0xa37/0x1080
  [show_state_filter+326/368] show_state_filter+0x146/0x170
  [sysrq_handle_showstate+10/16] sysrq_handle_showstate+0xa/0x10
  [__handle_sysrq+123/288] __handle_sysrq+0x7b/0x120
  [handle_sysrq+40/64] handle_sysrq+0x28/0x40
  [kbd_event+1045/1680] kbd_event+0x415/0x690
  [input_pass_event+206/208] input_pass_event+0xce/0xd0
  [input_handle_event+170/928] input_handle_event+0xaa/0x3a0
  [input_event+95/112] input_event+0x5f/0x70
  [atkbd_interrupt+434/1456] atkbd_interrupt+0x1b2/0x5b0
  [serio_interrupt+59/128] serio_interrupt+0x3b/0x80
  [i8042_interrupt+263/576] i8042_interrupt+0x107/0x240
  [handle_IRQ_event+40/96] handle_IRQ_event+0x28/0x60
  [handle_edge_irq+175/320] handle_edge_irq+0xaf/0x140
  [do_IRQ+64/128] do_IRQ+0x40/0x80
  [common_interrupt+46/52] common_interrupt+0x2e/0x34

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

parent 143a5d32

kernel/sched_debug.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -80,6 +80,7 @@ print_task(struct seq_file m, struct rq rq, struct task_struct *p)
		static void print_rq(struct seq_file m, struct rq rq, int rq_cpu)
		{
		struct task_struct g, p;
		unsigned long flags;

		SEQ_printf(m,
		"\nrunnable tasks:\n"
		@@ -88,7 +89,7 @@ static void print_rq(struct seq_file m, struct rq rq, int rq_cpu)
		"------------------------------------------------------"
		"----------------------------------------------------\n");

		read_lock_irq(&tasklist_lock);
		read_lock_irqsave(&tasklist_lock, flags);

		do_each_thread(g, p) {
		if (!p->se.on_rq \|\| task_cpu(p) != rq_cpu)
		@@ -97,7 +98,7 @@ static void print_rq(struct seq_file m, struct rq rq, int rq_cpu)
		print_task(m, rq, p);
		} while_each_thread(g, p);

		read_unlock_irq(&tasklist_lock);
		read_unlock_irqrestore(&tasklist_lock, flags);
		}

		void print_cfs_rq(struct seq_file m, int cpu, struct cfs_rq cfs_rq)

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