torture: Convert torture_shutdown() to hrtimer

Upcoming changes to the timer wheel introduce significant inaccuracy
and possibly also an ultimate limit on timeout duration.  This is a
problem for the current implementation of torture_shutdown() because
(1) shutdown times are user-specified, and can therefore be quite long,
and (2) the torture scripting will kill a test instance that runs for
more than a few minutes longer than scheduled.  This commit therefore
converts the torture_shutdown() timed waits to an hrtimer, thus avoiding
too-short torture test runs as well as death by scripting.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
This commit is contained in:
Paul E. McKenney 2016-06-18 07:45:43 -07:00
parent 29b4817d40
commit 31257c3c8b

View File

@ -43,6 +43,7 @@
#include <linux/stat.h>
#include <linux/slab.h>
#include <linux/trace_clock.h>
#include <linux/ktime.h>
#include <asm/byteorder.h>
#include <linux/torture.h>
@ -446,9 +447,8 @@ EXPORT_SYMBOL_GPL(torture_shuffle_cleanup);
* Variables for auto-shutdown. This allows "lights out" torture runs
* to be fully scripted.
*/
static int shutdown_secs; /* desired test duration in seconds. */
static struct task_struct *shutdown_task;
static unsigned long shutdown_time; /* jiffies to system shutdown. */
static ktime_t shutdown_time; /* time to system shutdown. */
static void (*torture_shutdown_hook)(void);
/*
@ -471,20 +471,20 @@ EXPORT_SYMBOL_GPL(torture_shutdown_absorb);
*/
static int torture_shutdown(void *arg)
{
long delta;
unsigned long jiffies_snap;
ktime_t ktime_snap;
VERBOSE_TOROUT_STRING("torture_shutdown task started");
jiffies_snap = jiffies;
while (ULONG_CMP_LT(jiffies_snap, shutdown_time) &&
ktime_snap = ktime_get();
while (ktime_before(ktime_snap, shutdown_time) &&
!torture_must_stop()) {
delta = shutdown_time - jiffies_snap;
if (verbose)
pr_alert("%s" TORTURE_FLAG
"torture_shutdown task: %lu jiffies remaining\n",
torture_type, delta);
schedule_timeout_interruptible(delta);
jiffies_snap = jiffies;
"torture_shutdown task: %llu ms remaining\n",
torture_type,
ktime_ms_delta(shutdown_time, ktime_snap));
set_current_state(TASK_INTERRUPTIBLE);
schedule_hrtimeout(&shutdown_time, HRTIMER_MODE_ABS);
ktime_snap = ktime_get();
}
if (torture_must_stop()) {
torture_kthread_stopping("torture_shutdown");
@ -511,10 +511,9 @@ int torture_shutdown_init(int ssecs, void (*cleanup)(void))
{
int ret = 0;
shutdown_secs = ssecs;
torture_shutdown_hook = cleanup;
if (shutdown_secs > 0) {
shutdown_time = jiffies + shutdown_secs * HZ;
if (ssecs > 0) {
shutdown_time = ktime_add(ktime_get(), ktime_set(ssecs, 0));
ret = torture_create_kthread(torture_shutdown, NULL,
shutdown_task);
}