linux/kernel/backtracetest.c
Tejun Heo 7245d24f87 backtracetest: Convert from tasklet to BH workqueue
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@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
2024-02-05 13:22:34 -10:00

79 lines
1.8 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Simple stack backtrace regression test module
*
* (C) Copyright 2008 Intel Corporation
* Author: Arjan van de Ven <arjan@linux.intel.com>
*/
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/stacktrace.h>
static void backtrace_test_normal(void)
{
pr_info("Testing a backtrace from process context.\n");
pr_info("The following trace is a kernel self test and not a bug!\n");
dump_stack();
}
static void backtrace_test_bh_workfn(struct work_struct *work)
{
dump_stack();
}
static DECLARE_WORK(backtrace_bh_work, &backtrace_test_bh_workfn);
static void backtrace_test_bh(void)
{
pr_info("Testing a backtrace from BH context.\n");
pr_info("The following trace is a kernel self test and not a bug!\n");
queue_work(system_bh_wq, &backtrace_bh_work);
flush_work(&backtrace_bh_work);
}
#ifdef CONFIG_STACKTRACE
static void backtrace_test_saved(void)
{
unsigned long entries[8];
unsigned int nr_entries;
pr_info("Testing a saved backtrace.\n");
pr_info("The following trace is a kernel self test and not a bug!\n");
nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 0);
stack_trace_print(entries, nr_entries, 0);
}
#else
static void backtrace_test_saved(void)
{
pr_info("Saved backtrace test skipped.\n");
}
#endif
static int backtrace_regression_test(void)
{
pr_info("====[ backtrace testing ]===========\n");
backtrace_test_normal();
backtrace_test_bh();
backtrace_test_saved();
pr_info("====[ end of backtrace testing ]====\n");
return 0;
}
static void exitf(void)
{
}
module_init(backtrace_regression_test);
module_exit(exitf);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Arjan van de Ven <arjan@linux.intel.com>");