The only generic interface to execute asynchronously in the BH context is
tasklet; however, it's marked deprecated and has some design flaws. To
replace tasklets, BH workqueue support was recently added. A BH workqueue
behaves similarly to regular workqueues except that the queued work items
are executed in the BH context.
This patch converts backtracetest from tasklet to BH workqueue.
- Replace "irq" with "bh" in names and message to better reflect what's
happening.
- Replace completion usage with a flush_work() call.
Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
Cc: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx>
---
kernel/backtracetest.c | 18 +++++++-----------
1 file changed, 7 insertions(+), 11 deletions(-)
diff --git a/kernel/backtracetest.c b/kernel/backtracetest.c
index 370217dd7e39..a4181234232b 100644
--- a/kernel/backtracetest.c
+++ b/kernel/backtracetest.c
@@ -21,24 +21,20 @@ static void backtrace_test_normal(void)
dump_stack();
}
-static DECLARE_COMPLETION(backtrace_work);
-
-static void backtrace_test_irq_callback(unsigned long data)
+static void backtrace_test_bh_workfn(struct work_struct *work)
{
dump_stack();
- complete(&backtrace_work);
}
-static DECLARE_TASKLET_OLD(backtrace_tasklet, &backtrace_test_irq_callback);
+static DECLARE_WORK(backtrace_bh_work, &backtrace_test_bh_workfn);
-static void backtrace_test_irq(void)
+static void backtrace_test_bh(void)
{
- pr_info("Testing a backtrace from irq context.\n");
+ pr_info("Testing a backtrace from BH context.\n");
pr_info("The following trace is a kernel self test and not a bug!\n");
- init_completion(&backtrace_work);
- tasklet_schedule(&backtrace_tasklet);
- wait_for_completion(&backtrace_work);
+ queue_work(system_bh_wq, &backtrace_bh_work);
+ flush_work(&backtrace_bh_work);
}
#ifdef CONFIG_STACKTRACE
@@ -65,7 +61,7 @@ static int backtrace_regression_test(void)
pr_info("====[ backtrace testing ]===========\n");
backtrace_test_normal();
- backtrace_test_irq();
+ backtrace_test_bh();
backtrace_test_saved();
pr_info("====[ end of backtrace testing ]====\n");
--
2.43.0
