From ab63a633cf072c719f885e46fa4814624312f672 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 25 Oct 2007 14:02:45 +0200 Subject: [PATCH] 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 Signed-off-by: Ingo Molnar --- kernel/sched_debug.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c index e6fb392e5164..415e5c385542 100644 --- a/kernel/sched_debug.c +++ b/kernel/sched_debug.c @@ -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) -- 2.30.2