#include <sys/condvar.h>
#include <sys/time.h>
+#include <sys/sysmacros.h>
#include <linux/hrtimer.h>
#include <linux/compiler_compat.h>
+#include <linux/mod_compat.h>
#include <linux/sched.h>
#include <linux/sched/signal.h>
#endif
+#define MAX_HRTIMEOUT_SLACK_US 1000
+unsigned int spl_schedule_hrtimeout_slack_us = 0;
+
+static int
+param_set_hrtimeout_slack(const char *buf, zfs_kernel_param_t *kp)
+{
+ unsigned long val;
+ int error;
+
+ error = kstrtoul(buf, 0, &val);
+ if (error)
+ return (error);
+
+ if (val > MAX_HRTIMEOUT_SLACK_US)
+ return (-EINVAL);
+
+ error = param_set_uint(buf, kp);
+ if (error < 0)
+ return (error);
+
+ return (0);
+}
+
+module_param_call(spl_schedule_hrtimeout_slack_us, param_set_hrtimeout_slack,
+ param_get_uint, &spl_schedule_hrtimeout_slack_us, 0644);
+MODULE_PARM_DESC(spl_schedule_hrtimeout_slack_us,
+ "schedule_hrtimeout_range() delta/slack value in us, default(0)");
+
void
__cv_init(kcondvar_t *cvp, char *name, kcv_type_t type, void *arg)
{
*/
static clock_t
__cv_timedwait_hires(kcondvar_t *cvp, kmutex_t *mp, hrtime_t expire_time,
- int state)
+ hrtime_t res, int state)
{
DEFINE_WAIT(wait);
kmutex_t *m;
hrtime_t time_left;
ktime_t ktime_left;
+ u64 slack = 0;
ASSERT(cvp);
ASSERT(mp);
* race where 'cvp->cv_waiters > 0' but the list is empty.
*/
mutex_exit(mp);
- /*
- * Allow a 100 us range to give kernel an opportunity to coalesce
- * interrupts
- */
+
ktime_left = ktime_set(0, time_left);
- schedule_hrtimeout_range(&ktime_left, 100 * NSEC_PER_USEC,
- HRTIMER_MODE_REL);
+ slack = MIN(MAX(res, spl_schedule_hrtimeout_slack_us * NSEC_PER_USEC),
+ MAX_HRTIMEOUT_SLACK_US * NSEC_PER_USEC);
+ schedule_hrtimeout_range(&ktime_left, slack, HRTIMER_MODE_REL);
/* No more waiters a different mutex could be used */
if (atomic_dec_and_test(&cvp->cv_waiters)) {
cv_timedwait_hires_common(kcondvar_t *cvp, kmutex_t *mp, hrtime_t tim,
hrtime_t res, int flag, int state)
{
- if (res > 1) {
- /*
- * Align expiration to the specified resolution.
- */
- if (flag & CALLOUT_FLAG_ROUNDUP)
- tim += res - 1;
- tim = (tim / res) * res;
- }
-
if (!(flag & CALLOUT_FLAG_ABSOLUTE))
tim += gethrtime();
- return (__cv_timedwait_hires(cvp, mp, tim, state));
+ return (__cv_timedwait_hires(cvp, mp, tim, res, state));
}
clock_t