From 4e6a0535dd036377961027262aecb138099f925d Mon Sep 17 00:00:00 2001 From: Vegard Nossum Date: Fri, 27 Jun 2008 18:06:54 +0200 Subject: backtrace: replace timer with tasklet + completions On qemu, the backtrace would show up _after_ the "end of backtrace testing" message. This patch changes it to use completions instead, which will guarantee that no such race exists. Cc: Arjan van de Ven Signed-off-by: Vegard Nossum Cc: Arjan van de Ven Cc: Andrew Morton Signed-off-by: Ingo Molnar --- kernel/backtracetest.c | 37 ++++++++++++++++++++++++++----------- 1 file changed, 26 insertions(+), 11 deletions(-) diff --git a/kernel/backtracetest.c b/kernel/backtracetest.c index 50f7abd0813d..a5e026bc45c4 100644 --- a/kernel/backtracetest.c +++ b/kernel/backtracetest.c @@ -10,18 +10,39 @@ * of the License. */ +#include #include +#include #include #include #include -static struct timer_list backtrace_timer; +static void backtrace_test_normal(void) +{ + printk("Testing a backtrace from process context.\n"); + printk("The following trace is a kernel self test and not a bug!\n"); + + dump_stack(); +} + +static DECLARE_COMPLETION(backtrace_work); + +static void backtrace_test_irq_callback(unsigned long data) +{ + dump_stack(); + complete(&backtrace_work); +} + +static DECLARE_TASKLET(backtrace_tasklet, &backtrace_test_irq_callback, 0); -static void backtrace_test_timer(unsigned long data) +static void backtrace_test_irq(void) { printk("Testing a backtrace from irq context.\n"); printk("The following trace is a kernel self test and not a bug!\n"); - dump_stack(); + + init_completion(&backtrace_work); + tasklet_schedule(&backtrace_tasklet); + wait_for_completion(&backtrace_work); } #ifdef CONFIG_STACKTRACE @@ -51,17 +72,11 @@ static void backtrace_test_saved(void) static int backtrace_regression_test(void) { printk("====[ backtrace testing ]===========\n"); - printk("Testing a backtrace from process context.\n"); - printk("The following trace is a kernel self test and not a bug!\n"); - dump_stack(); + backtrace_test_normal(); + backtrace_test_irq(); backtrace_test_saved(); - init_timer(&backtrace_timer); - backtrace_timer.function = backtrace_test_timer; - mod_timer(&backtrace_timer, jiffies + 10); - - msleep(10); printk("====[ end of backtrace testing ]====\n"); return 0; } -- cgit v1.2.1