Merge branch 'timers/range-hrtimers' into v28-range-hrtimers-for-linus-v2

Conflicts:

	kernel/time/tick-sched.c

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

30 files changed, 710 insertions, 379 deletions

diff --git a/arch/alpha/kernel/osf_sys.c b/arch/alpha/kernel/osf_sys.c
index 8509dad..8e19acb 100644
--- a/arch/alpha/kernel/osf_sys.c
+++ b/arch/alpha/kernel/osf_sys.c
@@ -986,10 +986,12 @@ asmlinkage int
 osf_select(int n, fd_set __user *inp, fd_set __user *outp, fd_set __user *exp,
 	   struct timeval32 __user *tvp)
 {
-	s64 timeout = MAX_SCHEDULE_TIMEOUT;
+	struct timespec end_time, *to = NULL;
 	if (tvp) {
 		time_t sec, usec;
 
+		to = &end_time;
+
 		if (!access_ok(VERIFY_READ, tvp, sizeof(*tvp))
 		    || __get_user(sec, &tvp->tv_sec)
 		    || __get_user(usec, &tvp->tv_usec)) {
@@ -999,14 +1001,13 @@ osf_select(int n, fd_set __user *inp, fd_set __user *outp, fd_set __user *exp,
 		if (sec < 0 || usec < 0)
 			return -EINVAL;
 
-		if ((unsigned long) sec < MAX_SELECT_SECONDS) {
-			timeout = (usec + 1000000/HZ - 1) / (1000000/HZ);
-			timeout += sec * (unsigned long) HZ;
-		}
+		if (poll_select_set_timeout(to, sec, usec * NSEC_PER_USEC))
+			return -EINVAL;		
+
 	}
 
 	/* OSF does not copy back the remaining time.  */
-	return core_sys_select(n, inp, outp, exp, &timeout);
+	return core_sys_select(n, inp, outp, exp, to);
 }
 
 struct rusage32 {
diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c
index c0699f0..a312c9e 100644
--- a/arch/ia64/kvm/kvm-ia64.c
+++ b/arch/ia64/kvm/kvm-ia64.c
@@ -1114,7 +1114,7 @@ static void kvm_migrate_hlt_timer(struct kvm_vcpu *vcpu)
 	struct hrtimer *p_ht = &vcpu->arch.hlt_timer;
 
 	if (hrtimer_cancel(p_ht))
-		hrtimer_start(p_ht, p_ht->expires, HRTIMER_MODE_ABS);
+		hrtimer_start_expires(p_ht, HRTIMER_MODE_ABS);
 }
 
 static enum hrtimer_restart hlt_timer_fn(struct hrtimer *data)
diff --git a/arch/powerpc/oprofile/cell/spu_profiler.c b/arch/powerpc/oprofile/cell/spu_profiler.c
index 380d7e2..02ffe06 100644
--- a/arch/powerpc/oprofile/cell/spu_profiler.c
+++ b/arch/powerpc/oprofile/cell/spu_profiler.c
@@ -196,7 +196,7 @@ int start_spu_profiling(unsigned int cycles_reset)
 	pr_debug("timer resolution: %lu\n", TICK_NSEC);
 	kt = ktime_set(0, profiling_interval);
 	hrtimer_init(&timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
-	timer.expires = kt;
+	hrtimer_set_expires(&timer, kt);
 	timer.function = profile_spus;
 
 	/* Allocate arrays for collecting SPU PC samples */
diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c
index 634132a..11c6725 100644
--- a/arch/x86/kvm/i8254.c
+++ b/arch/x86/kvm/i8254.c
@@ -204,10 +204,10 @@ static int __pit_timer_fn(struct kvm_kpit_state *ps)
 	if (vcpu0 && waitqueue_active(&vcpu0->wq))
 		wake_up_interruptible(&vcpu0->wq);
 
-	pt->timer.expires = ktime_add_ns(pt->timer.expires, pt->period);
-	pt->scheduled = ktime_to_ns(pt->timer.expires);
+	hrtimer_add_expires_ns(&pt->timer, pt->period);
+	pt->scheduled = hrtimer_get_expires_ns(&pt->timer);
 	if (pt->period)
-		ps->channels[0].count_load_time = pt->timer.expires;
+		ps->channels[0].count_load_time = hrtimer_get_expires(&pt->timer);
 
 	return (pt->period == 0 ? 0 : 1);
 }
@@ -257,7 +257,7 @@ void __kvm_migrate_pit_timer(struct kvm_vcpu *vcpu)
 
 	timer = &pit->pit_state.pit_timer.timer;
 	if (hrtimer_cancel(timer))
-		hrtimer_start(timer, timer->expires, HRTIMER_MODE_ABS);
+		hrtimer_start_expires(timer, HRTIMER_MODE_ABS);
 }
 
 static void destroy_pit_timer(struct kvm_kpit_timer *pt)
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 6571926..0fc3cab 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -946,9 +946,7 @@ static int __apic_timer_fn(struct kvm_lapic *apic)
 
 	if (apic_lvtt_period(apic)) {
 		result = 1;
-		apic->timer.dev.expires = ktime_add_ns(
-					apic->timer.dev.expires,
-					apic->timer.period);
+		hrtimer_add_expires_ns(&apic->timer.dev, apic->timer.period);
 	}
 	return result;
 }
@@ -1117,7 +1115,7 @@ void __kvm_migrate_apic_timer(struct kvm_vcpu *vcpu)
 
 	timer = &apic->timer.dev;
 	if (hrtimer_cancel(timer))
-		hrtimer_start(timer, timer->expires, HRTIMER_MODE_ABS);
+		hrtimer_start_expires(timer, HRTIMER_MODE_ABS);
 }
 
 void kvm_lapic_sync_from_vapic(struct kvm_vcpu *vcpu)
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index 5ce07b5..2e31484 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -16,6 +16,7 @@
 #include <linux/cpu.h>
 #include <linux/cpuidle.h>
 #include <linux/ktime.h>
+#include <linux/hrtimer.h>
 
 #include "cpuidle.h"
 
@@ -60,6 +61,12 @@ static void cpuidle_idle_call(void)
 		return;
 	}
 
+	/*
+	 * run any timers that can be run now, at this point
+	 * before calculating the idle duration etc.
+	 */
+	hrtimer_peek_ahead_timers();
+
 	/* ask the governor for the next state */
 	next_state = cpuidle_curr_governor->select(dev);
 	if (need_resched())
diff --git a/drivers/s390/crypto/ap_bus.c b/drivers/s390/crypto/ap_bus.c
index 326db1e..e3fe683 100644
--- a/drivers/s390/crypto/ap_bus.c
+++ b/drivers/s390/crypto/ap_bus.c
@@ -659,9 +659,9 @@ static ssize_t poll_timeout_store(struct bus_type *bus, const char *buf,
 	hr_time = ktime_set(0, poll_timeout);
 
 	if (!hrtimer_is_queued(&ap_poll_timer) ||
-	    !hrtimer_forward(&ap_poll_timer, ap_poll_timer.expires, hr_time)) {
-		ap_poll_timer.expires = hr_time;
-		hrtimer_start(&ap_poll_timer, hr_time, HRTIMER_MODE_ABS);
+	    !hrtimer_forward(&ap_poll_timer, hrtimer_get_expires(&ap_poll_timer), hr_time)) {
+		hrtimer_set_expires(&ap_poll_timer, hr_time);
+		hrtimer_start_expires(&ap_poll_timer, HRTIMER_MODE_ABS);
 	}
 	return count;
 }
diff --git a/fs/compat.c b/fs/compat.c
index 5f9ec44..3b58c32 100644
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -1475,6 +1475,57 @@ out_ret:
 
 #define __COMPAT_NFDBITS       (8 * sizeof(compat_ulong_t))
 
+static int poll_select_copy_remaining(struct timespec *end_time, void __user *p,
+				      int timeval, int ret)
+{
+	struct timespec ts;
+
+	if (!p)
+		return ret;
+
+	if (current->personality & STICKY_TIMEOUTS)
+		goto sticky;
+
+	/* No update for zero timeout */
+	if (!end_time->tv_sec && !end_time->tv_nsec)
+		return ret;
+
+	ktime_get_ts(&ts);
+	ts = timespec_sub(*end_time, ts);
+	if (ts.tv_sec < 0)
+		ts.tv_sec = ts.tv_nsec = 0;
+
+	if (timeval) {
+		struct compat_timeval rtv;
+
+		rtv.tv_sec = ts.tv_sec;
+		rtv.tv_usec = ts.tv_nsec / NSEC_PER_USEC;
+
+		if (!copy_to_user(p, &rtv, sizeof(rtv)))
+			return ret;
+	} else {
+		struct compat_timespec rts;
+
+		rts.tv_sec = ts.tv_sec;
+		rts.tv_nsec = ts.tv_nsec;
+
+		if (!copy_to_user(p, &rts, sizeof(rts)))
+			return ret;
+	}
+	/*
+	 * If an application puts its timeval in read-only memory, we
+	 * don't want the Linux-specific update to the timeval to
+	 * cause a fault after the select has completed
+	 * successfully. However, because we're not updating the
+	 * timeval, we can't restart the system call.
+	 */
+
+sticky:
+	if (ret == -ERESTARTNOHAND)
+		ret = -EINTR;
+	return ret;
+}
+
 /*
  * Ooo, nasty.  We need here to frob 32-bit unsigned longs to
  * 64-bit unsigned longs.
@@ -1556,7 +1607,8 @@ int compat_set_fd_set(unsigned long nr, compat_ulong_t __user *ufdset,
 	((unsigned long) (MAX_SCHEDULE_TIMEOUT / HZ)-1)
 
 int compat_core_sys_select(int n, compat_ulong_t __user *inp,
-	compat_ulong_t __user *outp, compat_ulong_t __user *exp, s64 *timeout)
+	compat_ulong_t __user *outp, compat_ulong_t __user *exp,
+	struct timespec *end_time)
 {
 	fd_set_bits fds;
 	void *bits;
@@ -1603,7 +1655,7 @@ int compat_core_sys_select(int n, compat_ulong_t __user *inp,
 	zero_fd_set(n, fds.res_out);
 	zero_fd_set(n, fds.res_ex);
 
-	ret = do_select(n, &fds, timeout);
+	ret = do_select(n, &fds, end_time);
 
 	if (ret < 0)
 		goto out;
@@ -1629,7 +1681,7 @@ asmlinkage long compat_sys_select(int n, compat_ulong_t __user *inp,
 	compat_ulong_t __user *outp, compat_ulong_t __user *exp,
 	struct compat_timeval __user *tvp)
 {
-	s64 timeout = -1;
+	struct timespec end_time, *to = NULL;
 	struct compat_timeval tv;
 	int ret;
 
@@ -1637,43 +1689,14 @@ asmlinkage long compat_sys_select(int n, compat_ulong_t __user *inp,
 		if (copy_from_user(&tv, tvp, sizeof(tv)))
 			return -EFAULT;
 
-		if (tv.tv_sec < 0 || tv.tv_usec < 0)
+		to = &end_time;
+		if (poll_select_set_timeout(to, tv.tv_sec,
+					    tv.tv_usec * NSEC_PER_USEC))
 			return -EINVAL;
-
-		/* Cast to u64 to make GCC stop complaining */
-		if ((u64)tv.tv_sec >= (u64)MAX_INT64_SECONDS)
-			timeout = -1;	/* infinite */
-		else {
-			timeout = DIV_ROUND_UP(tv.tv_usec, 1000000/HZ);
-			timeout += tv.tv_sec * HZ;
-		}
 	}
 
-	ret = compat_core_sys_select(n, inp, outp, exp, &timeout);
-
-	if (tvp) {
-		struct compat_timeval rtv;
-
-		if (current->personality & STICKY_TIMEOUTS)
-			goto sticky;
-		rtv.tv_usec = jiffies_to_usecs(do_div((*(u64*)&timeout), HZ));
-		rtv.tv_sec = timeout;
-		if (compat_timeval_compare(&rtv, &tv) >= 0)
-			rtv = tv;
-		if (copy_to_user(tvp, &rtv, sizeof(rtv))) {
-sticky:
-			/*
-			 * If an application puts its timeval in read-only
-			 * memory, we don't want the Linux-specific update to
-			 * the timeval to cause a fault after the select has
-			 * completed successfully. However, because we're not
-			 * updating the timeval, we can't restart the system
-			 * call.
-			 */
-			if (ret == -ERESTARTNOHAND)
-				ret = -EINTR;
-		}
-	}
+	ret = compat_core_sys_select(n, inp, outp, exp, to);
+	ret = poll_select_copy_remaining(&end_time, tvp, 1, ret);
 
 	return ret;
 }
@@ -1686,15 +1709,16 @@ asmlinkage long compat_sys_pselect7(int n, compat_ulong_t __user *inp,
 {
 	compat_sigset_t ss32;
 	sigset_t ksigmask, sigsaved;
-	s64 timeout = MAX_SCHEDULE_TIMEOUT;
 	struct compat_timespec ts;
+	struct timespec end_time, *to = NULL;
 	int ret;
 
 	if (tsp) {
 		if (copy_from_user(&ts, tsp, sizeof(ts)))
 			return -EFAULT;
 
-		if (ts.tv_sec < 0 || ts.tv_nsec < 0)
+		to = &end_time;
+		if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec))
 			return -EINVAL;
 	}
 
@@ -1709,51 +1733,8 @@ asmlinkage long compat_sys_pselect7(int n, compat_ulong_t __user *inp,
 		sigprocmask(SIG_SETMASK, &ksigmask, &sigsaved);
 	}
 
-	do {
-		if (tsp) {
-			if ((unsigned long)ts.tv_sec < MAX_SELECT_SECONDS) {
-				timeout = DIV_ROUND_UP(ts.tv_nsec, 1000000000/HZ);
-				timeout += ts.tv_sec * (unsigned long)HZ;
-				ts.tv_sec = 0;
-				ts.tv_nsec = 0;
-			} else {
-				ts.tv_sec -= MAX_SELECT_SECONDS;
-				timeout = MAX_SELECT_SECONDS * HZ;
-			}
-		}
-
-		ret = compat_core_sys_select(n, inp, outp, exp, &timeout);
-
-	} while (!ret && !timeout && tsp && (ts.tv_sec || ts.tv_nsec));
-
-	if (tsp) {
-		struct compat_timespec rts;
-
-		if (current->personality & STICKY_TIMEOUTS)
-			goto sticky;
-
-		rts.tv_sec = timeout / HZ;
-		rts.tv_nsec = (timeout % HZ) * (NSEC_PER_SEC/HZ);
-		if (rts.tv_nsec >= NSEC_PER_SEC) {
-			rts.tv_sec++;
-			rts.tv_nsec -= NSEC_PER_SEC;
-		}
-		if (compat_timespec_compare(&rts, &ts) >= 0)
-			rts = ts;
-		if (copy_to_user(tsp, &rts, sizeof(rts))) {
-sticky:
-			/*
-			 * If an application puts its timeval in read-only
-			 * memory, we don't want the Linux-specific update to
-			 * the timeval to cause a fault after the select has
-			 * completed successfully. However, because we're not
-			 * updating the timeval, we can't restart the system
-			 * call.
-			 */
-			if (ret == -ERESTARTNOHAND)
-				ret = -EINTR;
-		}
-	}
+	ret = compat_core_sys_select(n, inp, outp, exp, to);
+	ret = poll_select_copy_remaining(&end_time, tsp, 0, ret);
 
 	if (ret == -ERESTARTNOHAND) {
 		/*
@@ -1798,18 +1779,16 @@ asmlinkage long compat_sys_ppoll(struct pollfd __user *ufds,
 	compat_sigset_t ss32;
 	sigset_t ksigmask, sigsaved;
 	struct compat_timespec ts;
-	s64 timeout = -1;
+	struct timespec end_time, *to = NULL;
 	int ret;
 
 	if (tsp) {
 		if (copy_from_user(&ts, tsp, sizeof(ts)))
 			return -EFAULT;
 
-		/* We assume that ts.tv_sec is always lower than
-		   the number of seconds that can be expressed in
-		   an s64. Otherwise the compiler bitches at us */
-		timeout = DIV_ROUND_UP(ts.tv_nsec, 1000000000/HZ);
-		timeout += ts.tv_sec * HZ;
+		to = &end_time;
+		if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec))
+			return -EINVAL;
 	}
 
 	if (sigmask) {
@@ -1823,7 +1802,7 @@ asmlinkage long compat_sys_ppoll(struct pollfd __user *ufds,
 		sigprocmask(SIG_SETMASK, &ksigmask, &sigsaved);
 	}
 
-	ret = do_sys_poll(ufds, nfds, &timeout);
+	ret = do_sys_poll(ufds, nfds, to);
 
 	/* We can restart this syscall, usually */
 	if (ret == -EINTR) {
@@ -1841,31 +1820,7 @@ asmlinkage long compat_sys_ppoll(struct pollfd __user *ufds,
 	} else if (sigmask)
 		sigprocmask(SIG_SETMASK, &sigsaved, NULL);
 
-	if (tsp && timeout >= 0) {
-		struct compat_timespec rts;
-
-		if (current->personality & STICKY_TIMEOUTS)
-			goto sticky;
-		/* Yes, we know it's actually an s64, but it's also positive. */
-		rts.tv_nsec = jiffies_to_usecs(do_div((*(u64*)&timeout), HZ)) *
-					1000;
-		rts.tv_sec = timeout;
-		if (compat_timespec_compare(&rts, &ts) >= 0)
-			rts = ts;
-		if (copy_to_user(tsp, &rts, sizeof(rts))) {
-sticky:
-			/*
-			 * If an application puts its timeval in read-only
-			 * memory, we don't want the Linux-specific update to
-			 * the timeval to cause a fault after the select has
-			 * completed successfully. However, because we're not
-			 * updating the timeval, we can't restart the system
-			 * call.
-			 */
-			if (ret == -ERESTARTNOHAND && timeout >= 0)
-				ret = -EINTR;
-		}
-	}
+	ret = poll_select_copy_remaining(&end_time, tsp, 0, ret);
 
 	return ret;
 }
diff --git a/fs/select.c b/fs/select.c
index da0e882..448e440 100644
--- a/fs/select.c
+++ b/fs/select.c
@@ -24,9 +24,64 @@
 #include <linux/fdtable.h>
 #include <linux/fs.h>
 #include <linux/rcupdate.h>
+#include <linux/hrtimer.h>
 
 #include <asm/uaccess.h>
 
+
+/*
+ * Estimate expected accuracy in ns from a timeval.
+ *
+ * After quite a bit of churning around, we've settled on
+ * a simple thing of taking 0.1% of the timeout as the
+ * slack, with a cap of 100 msec.
+ * "nice" tasks get a 0.5% slack instead.
+ *
+ * Consider this comment an open invitation to come up with even
+ * better solutions..
+ */
+
+static long __estimate_accuracy(struct timespec *tv)
+{
+	long slack;
+	int divfactor = 1000;
+
+	if (task_nice(current) > 0)
+		divfactor = divfactor / 5;
+
+	slack = tv->tv_nsec / divfactor;
+	slack += tv->tv_sec * (NSEC_PER_SEC/divfactor);
+
+	if (slack > 100 * NSEC_PER_MSEC)
+		slack =  100 * NSEC_PER_MSEC;
+
+	if (slack < 0)
+		slack = 0;
+	return slack;
+}
+
+static long estimate_accuracy(struct timespec *tv)
+{
+	unsigned long ret;
+	struct timespec now;
+
+	/*
+	 * Realtime tasks get a slack of 0 for obvious reasons.
+	 */
+
+	if (rt_task(current))
+		return 0;
+
+	ktime_get_ts(&now);
+	now = timespec_sub(*tv, now);
+	ret = __estimate_accuracy(&now);
+	if (ret < current->timer_slack_ns)
+		return current->timer_slack_ns;
+	return ret;
+}
+
+
+
 struct poll_table_page {
 	struct poll_table_page * next;
 	struct poll_table_entry * entry;
@@ -130,6 +185,79 @@ static void __pollwait(struct file *filp, wait_queue_head_t *wait_address,
 	add_wait_queue(wait_address, &entry->wait);
 }
 
+/**
+ * poll_select_set_timeout - helper function to setup the timeout value
+ * @to:		pointer to timespec variable for the final timeout
+ * @sec:	seconds (from user space)
+ * @nsec:	nanoseconds (from user space)
+ *
+ * Note, we do not use a timespec for the user space value here, That
+ * way we can use the function for timeval and compat interfaces as well.
+ *
+ * Returns -EINVAL if sec/nsec are not normalized. Otherwise 0.
+ */
+int poll_select_set_timeout(struct timespec *to, long sec, long nsec)
+{
+	struct timespec ts = {.tv_sec = sec, .tv_nsec = nsec};
+
+	if (!timespec_valid(&ts))
+		return -EINVAL;
+
+	/* Optimize for the zero timeout value here */
+	if (!sec && !nsec) {
+		to->tv_sec = to->tv_nsec = 0;
+	} else {
+		ktime_get_ts(to);
+		*to = timespec_add_safe(*to, ts);
+	}
+	return 0;
+}
+
+static int poll_select_copy_remaining(struct timespec *end_time, void __user *p,
+				      int timeval, int ret)
+{
+	struct timespec rts;
+	struct timeval rtv;
+
+	if (!p)
+		return ret;
+
+	if (current->personality & STICKY_TIMEOUTS)
+		goto sticky;
+
+	/* No update for zero timeout */
+	if (!end_time->tv_sec && !end_time->tv_nsec)
+		return ret;
+
+	ktime_get_ts(&rts);
+	rts = timespec_sub(*end_time, rts);
+	if (rts.tv_sec < 0)
+		rts.tv_sec = rts.tv_nsec = 0;
+
+	if (timeval) {
+		rtv.tv_sec = rts.tv_sec;
+		rtv.tv_usec = rts.tv_nsec / NSEC_PER_USEC;
+
+		if (!copy_to_user(p, &rtv, sizeof(rtv)))
+			return ret;
+
+	} else if (!copy_to_user(p, &rts, sizeof(rts)))
+		return ret;
+
+	/*
+	 * If an application puts its timeval in read-only memory, we
+	 * don't want the Linux-specific update to the timeval to
+	 * cause a fault after the select has completed
+	 * successfully. However, because we're not updating the
+	 * timeval, we can't restart the system call.
+	 */
+
+sticky:
+	if (ret == -ERESTARTNOHAND)
+		ret = -EINTR;
+	return ret;
+}
+
 #define FDS_IN(fds, n)		(fds->in + n)
 #define FDS_OUT(fds, n)		(fds->out + n)
 #define FDS_EX(fds, n)		(fds->ex + n)
@@ -182,11 +310,13 @@ get_max:
 #define POLLOUT_SET (POLLWRBAND | POLLWRNORM | POLLOUT | POLLERR)
 #define POLLEX_SET (POLLPRI)
 
-int do_select(int n, fd_set_bits *fds, s64 *timeout)
+int do_select(int n, fd_set_bits *fds, struct timespec *end_time)
 {
+	ktime_t expire, *to = NULL;
 	struct poll_wqueues table;
 	poll_table *wait;
-	int retval, i;
+	int retval, i, timed_out = 0;
+	unsigned long slack = 0;
 
 	rcu_read_lock();
 	retval = max_select_fd(n, fds);
@@ -198,12 +328,17 @@ int do_select(int n, fd_set_bits *fds, s64 *timeout)
 
 	poll_initwait(&table);
 	wait = &table.pt;
-	if (!*timeout)
+	if (end_time && !end_time->tv_sec && !end_time->tv_nsec) {
 		wait = NULL;
+		timed_out = 1;
+	}
+
+	if (end_time && !timed_out)
+		slack = estimate_accuracy(end_time);
+
 	retval = 0;
 	for (;;) {
 		unsigned long *rinp, *routp, *rexp, *inp, *outp, *exp;
-		long __timeout;
 
 		set_current_state(TASK_INTERRUPTIBLE);
 
@@ -259,27 +394,25 @@ int do_select(int n, fd_set_bits *fds, s64 *timeout)
 			cond_resched();
 		}
 		wait = NULL;
-		if (retval || !*timeout || signal_pending(current))
+		if (retval || timed_out || signal_pending(current))
 			break;
 		if (table.error) {
 			retval = table.error;
 			break;
 		}
 
-		if (*timeout < 0) {
-			/* Wait indefinitely */
-			__timeout = MAX_SCHEDULE_TIMEOUT;
-		} else if (unlikely(*timeout >= (s64)MAX_SCHEDULE_TIMEOUT - 1)) {
-			/* Wait for longer than MAX_SCHEDULE_TIMEOUT. Do it in a loop */
-			__timeout = MAX_SCHEDULE_TIMEOUT - 1;
-			*timeout -= __timeout;
-		} else {
-			__timeout = *timeout;
-			*timeout = 0;
+		/*
+		 * If this is the first loop and we have a timeout
+		 * given, then we convert to ktime_t and set the to
+		 * pointer to the expiry value.
+		 */
+		if (end_time && !to) {
+			expire = timespec_to_ktime(*end_time);
+			to = &expire;
 		}
-		__timeout = schedule_timeout(__timeout);
-		if (*timeout >= 0)
-			*timeout += __timeout;
+
+		if (!schedule_hrtimeout_range(to, slack, HRTIMER_MODE_ABS))
+			timed_out = 1;
 	}
 	__set_current_state(TASK_RUNNING);
 
@@ -300,7 +433,7 @@ int do_select(int n, fd_set_bits *fds, s64 *timeout)
 	((unsigned long) (MAX_SCHEDULE_TIMEOUT / HZ)-1)
 
 int core_sys_select(int n, fd_set __user *inp, fd_set __user *outp,
-			   fd_set __user *exp, s64 *timeout)
+			   fd_set __user *exp, struct timespec *end_time)
 {
 	fd_set_bits fds;
 	void *bits;
@@ -351,7 +484,7 @@ int core_sys_select(int n, fd_set __user *inp, fd_set __user *outp,
 	zero_fd_set(n, fds.res_out);
 	zero_fd_set(n, fds.res_ex);
 
-	ret = do_select(n, &fds, timeout);
+	ret = do_select(n, &fds, end_time);
 
 	if (ret < 0)
 		goto out;
@@ -377,7 +510,7 @@ out_nofds:
 asmlinkage long sys_select(int n, fd_set __user *inp, fd_set __user *outp,
 			fd_set __user *exp, struct timeval __user *tvp)
 {
-	s64 timeout = -1;
+	struct timespec end_time, *to = NULL;
 	struct timeval tv;
 	int ret;
 
@@ -385,43 +518,14 @@ asmlinkage long sys_select(int n, fd_set __user *inp, fd_set __user *outp,
 		if (copy_from_user(&tv, tvp, sizeof(tv)))
 			return -EFAULT;
 
-		if (tv.tv_sec < 0 || tv.tv_usec < 0)
+		to = &end_time;
+		if (poll_select_set_timeout(to, tv.tv_sec,
+					    tv.tv_usec * NSEC_PER_USEC))
 			return -EINVAL;
-
-		/* Cast to u64 to make GCC stop complaining */
-		if ((u64)tv.tv_sec >= (u64)MAX_INT64_SECONDS)
-			timeout = -1;	/* infinite */
-		else {
-			timeout = DIV_ROUND_UP(tv.tv_usec, USEC_PER_SEC/HZ);
-			timeout += tv.tv_sec * HZ;
-		}
 	}
 
-	ret = core_sys_select(n, inp, outp, exp, &timeout);
-
-	if (tvp) {
-		struct timeval rtv;
-
-		if (current->personality & STICKY_TIMEOUTS)
-			goto sticky;
-		rtv.tv_usec = jiffies_to_usecs(do_div((*(u64*)&timeout), HZ));
-		rtv.tv_sec = timeout;
-		if (timeval_compare(&rtv, &tv) >= 0)
-			rtv = tv;
-		if (copy_to_user(tvp, &rtv, sizeof(rtv))) {
-sticky:
-			/*
-			 * If an application puts its timeval in read-only
-			 * memory, we don't want the Linux-specific update to
-			 * the timeval to cause a fault after the select has
-			 * completed successfully. However, because we're not
-			 * updating the timeval, we can't restart the system
-			 * call.
-			 */
-			if (ret == -ERESTARTNOHAND)
-				ret = -EINTR;
-		}
-	}
+	ret = core_sys_select(n, inp, outp, exp, to);
+	ret = poll_select_copy_remaining(&end_time, tvp, 1, ret);
 
 	return ret;
 }
@@ -431,25 +535,17 @@ asmlinkage long sys_pselect7(int n, fd_set __user *inp, fd_set __user *outp,
 		fd_set __user *exp, struct timespec __user *tsp,
 		const sigset_t __user *sigmask, size_t sigsetsize)
 {
-	s64 timeout = MAX_SCHEDULE_TIMEOUT;
 	sigset_t ksigmask, sigsaved;
-	struct timespec ts;
+	struct timespec ts, end_time, *to = NULL;
 	int ret;
 
 	if (tsp) {
 		if (copy_from_user(&ts, tsp, sizeof(ts)))
 			return -EFAULT;
 
-		if (ts.tv_sec < 0 || ts.tv_nsec < 0)
+		to = &end_time;
+		if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec))
 			return -EINVAL;
-
-		/* Cast to u64 to make GCC stop complaining */
-		if ((u64)ts.tv_sec >= (u64)MAX_INT64_SECONDS)
-			timeout = -1;	/* infinite */
-		else {
-			timeout = DIV_ROUND_UP(ts.tv_nsec, NSEC_PER_SEC/HZ);
-			timeout += ts.tv_sec * HZ;
-		}
 	}
 
 	if (sigmask) {
@@ -463,32 +559,8 @@ asmlinkage long sys_pselect7(int n, fd_set __user *inp, fd_set __user *outp,
 		sigprocmask(SIG_SETMASK, &ksigmask, &sigsaved);
 	}
 
-	ret = core_sys_select(n, inp, outp, exp, &timeout);
-
-	if (tsp) {
-		struct timespec rts;
-
-		if (current->personality & STICKY_TIMEOUTS)
-			goto sticky;
-		rts.tv_nsec = jiffies_to_usecs(do_div((*(u64*)&timeout), HZ)) *
-						1000;
-		rts.tv_sec = timeout;
-		if (timespec_compare(&rts, &ts) >= 0)
-			rts = ts;
-		if (copy_to_user(tsp, &rts, sizeof(rts))) {
-sticky:
-			/*
-			 * If an application puts its timeval in read-only
-			 * memory, we don't want the Linux-specific update to
-			 * the timeval to cause a fault after the select has
-			 * completed successfully. However, because we're not
-			 * updating the timeval, we can't restart the system
-			 * call.
-			 */
-			if (ret == -ERESTARTNOHAND)
-				ret = -EINTR;
-		}
-	}
+	ret = core_sys_select(n, inp, outp, exp, &end_time);
+	ret = poll_select_copy_remaining(&end_time, tsp, 0, ret);
 
 	if (ret == -ERESTARTNOHAND) {
 		/*
@@ -574,18 +646,24 @@ static inline unsigned int do_pollfd(struct pollfd *pollfd, poll_table *pwait)
 }
 
 static int do_poll(unsigned int nfds,  struct poll_list *list,
-		   struct poll_wqueues *wait, s64 *timeout)
+		   struct poll_wqueues *wait, struct timespec *end_time)
 {
-	int count = 0;
 	poll_table* pt = &wait->pt;
+	ktime_t expire, *to = NULL;
+	int timed_out = 0, count = 0;
+	unsigned long slack = 0;
 
 	/* Optimise the no-wait case */
-	if (!(*timeout))
+	if (end_time && !end_time->tv_sec && !end_time->tv_nsec) {
 		pt = NULL;
+		timed_out = 1;
+	}
+
+	if (end_time && !timed_out)
+		slack = estimate_accuracy(end_time);
 
 	for (;;) {
 		struct poll_list *walk;
-		long __timeout;
 
 		set_current_state(TASK_INTERRUPTIBLE);
 		for (walk = list; walk != NULL; walk = walk->next) {
@@ -617,27 +695,21 @@ static int do_poll(unsigned int nfds,  struct poll_list *list,
 			if (signal_pending(current))
 				count = -EINTR;
 		}
-		if (count || !*timeout)
+		if (count || timed_out)
 			break;
 
-		if (*timeout < 0) {
-			/* Wait indefinitely */
-			__timeout = MAX_SCHEDULE_TIMEOUT;
-		} else if (unlikely(*timeout >= (s64)MAX_SCHEDULE_TIMEOUT-1)) {
-			/*
-			 * Wait for longer than MAX_SCHEDULE_TIMEOUT. Do it in
-			 * a loop
-			 */
-			__timeout = MAX_SCHEDULE_TIMEOUT - 1;
-			*timeout -= __timeout;
-		} else {
-			__timeout = *timeout;
-			*timeout = 0;
+		/*
+		 * If this is the first loop and we have a timeout
+		 * given, then we convert to ktime_t and set the to
+		 * pointer to the expiry value.
+		 */
+		if (end_time && !to) {
+			expire = timespec_to_ktime(*end_time);
+			to = &expire;
 		}
 
-		__timeout = schedule_timeout(__timeout);
-		if (*timeout >= 0)
-			*timeout += __timeout;
+		if (!schedule_hrtimeout_range(to, slack, HRTIMER_MODE_ABS))
+			timed_out = 1;
 	}
 	__set_current_state(TASK_RUNNING);
 	return count;
@@ -646,7 +718,8 @@ static int do_poll(unsigned int nfds,  struct poll_list *list,
 #define N_STACK_PPS ((sizeof(stack_pps) - sizeof(struct poll_list))  / \
 			sizeof(struct pollfd))
 
-int do_sys_poll(struct pollfd __user *ufds, unsigned int nfds, s64 *timeout)
+int do_sys_poll(struct pollfd __user *ufds, unsigned int nfds,
+		struct timespec *end_time)
 {
 	struct poll_wqueues table;
  	int err = -EFAULT, fdcount, len, size;
@@ -686,7 +759,7 @@ int do_sys_poll(struct pollfd __user *ufds, unsigned int nfds, s64 *timeout)
 	}
 
 	poll_initwait(&table);
-	fdcount = do_poll(nfds, head, &table, timeout);
+	fdcount = do_poll(nfds, head, &table, end_time);
 	poll_freewait(&table);
 
 	for (walk = head; walk; walk = walk->next) {
@@ -712,16 +785,21 @@ out_fds:
 
 static long do_restart_poll(struct restart_block *restart_block)
 {
-	struct pollfd __user *ufds = (struct pollfd __user*)restart_block->arg0;
-	int nfds = restart_block->arg1;
-	s64 timeout = ((s64)restart_block->arg3<<32) | (s64)restart_block->arg2;
+	struct pollfd __user *ufds = restart_block->poll.ufds;
+	int nfds = restart_block->poll.nfds;
+	struct timespec *to = NULL, end_time;
 	int ret;
 
-	ret = do_sys_poll(ufds, nfds, &timeout);
+	if (restart_block->poll.has_timeout) {
+		end_time.tv_sec = restart_block->poll.tv_sec;
+		end_time.tv_nsec = restart_block->poll.tv_nsec;
+		to = &end_time;
+	}
+
+	ret = do_sys_poll(ufds, nfds, to);
+
 	if (ret == -EINTR) {
 		restart_block->fn = do_restart_poll;
-		restart_block->arg2 = timeout & 0xFFFFFFFF;
-		restart_block->arg3 = (u64)timeout >> 32;
 		ret = -ERESTART_RESTARTBLOCK;
 	}
 	return ret;
@@ -730,31 +808,32 @@ static long do_restart_poll(struct restart_block *restart_block)
 asmlinkage long sys_poll(struct pollfd __user *ufds, unsigned int nfds,
 			long timeout_msecs)
 {
-	s64 timeout_jiffies;
+	struct timespec end_time, *to = NULL;
 	int ret;
 
-	if (timeout_msecs > 0) {
-#if HZ > 1000
-		/* We can only overflow if HZ > 1000 */
-		if (timeout_msecs / 1000 > (s64)0x7fffffffffffffffULL / (s64)HZ)
-			timeout_jiffies = -1;
-		else
-#endif
-			timeout_jiffies = msecs_to_jiffies(timeout_msecs) + 1;
-	} else {
-		/* Infinite (< 0) or no (0) timeout */
-		timeout_jiffies = timeout_msecs;
+	if (timeout_msecs >= 0) {
+		to = &end_time;
+		poll_select_set_timeout(to, timeout_msecs / MSEC_PER_SEC,
+			NSEC_PER_MSEC * (timeout_msecs % MSEC_PER_SEC));
 	}
 
-	ret = do_sys_poll(ufds, nfds, &timeout_jiffies);
+	ret = do_sys_poll(ufds, nfds, to);
+
 	if (ret == -EINTR) {
 		struct restart_block *restart_block;
+
 		restart_block = &current_thread_info()->restart_block;
 		restart_block->fn = do_restart_poll;
-		restart_block->arg0 = (unsigned long)ufds;
-		restart_block->arg1 = nfds;
-		restart_block->arg2 = timeout_jiffies & 0xFFFFFFFF;
-		restart_block->arg3 = (u64)timeout_jiffies >> 32;
+		restart_block->poll.ufds = ufds;
+		restart_block->poll.nfds = nfds;
+
+		if (timeout_msecs >= 0) {
+			restart_block->poll.tv_sec = end_time.tv_sec;
+			restart_block->poll.tv_nsec = end_time.tv_nsec;
+			restart_block->poll.has_timeout = 1;
+		} else
+			restart_block->poll.has_timeout = 0;
+
 		ret = -ERESTART_RESTARTBLOCK;
 	}
 	return ret;
@@ -766,21 +845,16 @@ asmlinkage long sys_ppoll(struct pollfd __user *ufds, unsigned int nfds,
 	size_t sigsetsize)
 {
 	sigset_t ksigmask, sigsaved;
-	struct timespec ts;
-	s64 timeout = -1;
+	struct timespec ts, end_time, *to = NULL;
 	int ret;
 
 	if (tsp) {
 		if (copy_from_user(&ts, tsp, sizeof(ts)))
 			return -EFAULT;
 
-		/* Cast to u64 to make GCC stop complaining */
-		if ((u64)ts.tv_sec >= (u64)MAX_INT64_SECONDS)
-			timeout = -1;	/* infinite */
-		else {
-			timeout = DIV_ROUND_UP(ts.tv_nsec, NSEC_PER_SEC/HZ);
-			timeout += ts.tv_sec * HZ;
-		}
+		to = &end_time;
+		if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec))
+			return -EINVAL;
 	}
 
 	if (sigmask) {
@@ -794,7 +868,7 @@ asmlinkage long sys_ppoll(struct pollfd __user *ufds, unsigned int nfds,
 		sigprocmask(SIG_SETMASK, &ksigmask, &sigsaved);
 	}
 
-	ret = do_sys_poll(ufds, nfds, &timeout);
+	ret = do_sys_poll(ufds, nfds, to);
 
 	/* We can restart this syscall, usually */
 	if (ret == -EINTR) {
@@ -812,31 +886,7 @@ asmlinkage long sys_ppoll(struct pollfd __user *ufds, unsigned int nfds,
 	} else if (sigmask)
 		sigprocmask(SIG_SETMASK, &sigsaved, NULL);
 
-	if (tsp && timeout >= 0) {
-		struct timespec rts;
-
-		if (current->personality & STICKY_TIMEOUTS)
-			goto sticky;
-		/* Yes, we know it's actually an s64, but it's also positive. */
-		rts.tv_nsec = jiffies_to_usecs(do_div((*(u64*)&timeout), HZ)) *
-						1000;
-		rts.tv_sec = timeout;
-		if (timespec_compare(&rts, &ts) >= 0)
-			rts = ts;
-		if (copy_to_user(tsp, &rts, sizeof(rts))) {
-		sticky:
-			/*
-			 * If an application puts its timeval in read-only
-			 * memory, we don't want the Linux-specific update to
-			 * the timeval to cause a fault after the select has
-			 * completed successfully. However, because we're not
-			 * updating the timeval, we can't restart the system
-			 * call.
-			 */
-			if (ret == -ERESTARTNOHAND && timeout >= 0)
-				ret = -EINTR;
-		}
-	}
+	ret = poll_select_copy_remaining(&end_time, tsp, 0, ret);
 
 	return ret;
 }
diff --git a/fs/timerfd.c b/fs/timerfd.c
index c502c60..0862f0e 100644
--- a/fs/timerfd.c
+++ b/fs/timerfd.c
@@ -52,11 +52,9 @@ static enum hrtimer_restart timerfd_tmrproc(struct hrtimer *htmr)
 
 static ktime_t timerfd_get_remaining(struct timerfd_ctx *ctx)
 {
-	ktime_t now, remaining;
-
-	now = ctx->tmr.base->get_time();
-	remaining = ktime_sub(ctx->tmr.expires, now);
+	ktime_t remaining;
 
+	remaining = hrtimer_expires_remaining(&ctx->tmr);
 	return remaining.tv64 < 0 ? ktime_set(0, 0): remaining;
 }
 
@@ -74,7 +72,7 @@ static void timerfd_setup(struct timerfd_ctx *ctx, int flags,
 	ctx->ticks = 0;
 	ctx->tintv = timespec_to_ktime(ktmr->it_interval);
 	hrtimer_init(&ctx->tmr, ctx->clockid, htmode);
-	ctx->tmr.expires = texp;
+	hrtimer_set_expires(&ctx->tmr, texp);
 	ctx->tmr.function = timerfd_tmrproc;
 	if (texp.tv64 != 0)
 		hrtimer_start(&ctx->tmr, texp, htmode);
diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
index 9a4e35c..2b3645b 100644
--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -20,6 +20,8 @@
 #include <linux/init.h>
 #include <linux/list.h>
 #include <linux/wait.h>
+#include <linux/percpu.h>
+
 
 struct hrtimer_clock_base;
 struct hrtimer_cpu_base;
@@ -101,9 +103,14 @@ enum hrtimer_cb_mode {
 /**
  * struct hrtimer - the basic hrtimer structure
  * @node:	red black tree node for time ordered insertion
- * @expires:	the absolute expiry time in the hrtimers internal
+ * @_expires:	the absolute expiry time in the hrtimers internal
  *		representation. The time is related to the clock on
- *		which the timer is based.
+ *		which the timer is based. Is setup by adding
+ *		slack to the _softexpires value. For non range timers
+ *		identical to _softexpires.
+ * @_softexpires: the absolute earliest expiry time of the hrtimer.
+ *		The time which was given as expiry time when the timer
+ *		was armed.
  * @function:	timer expiry callback function
  * @base:	pointer to the timer base (per cpu and per clock)
  * @state:	state information (See bit values above)
@@ -121,7 +128,8 @@ enum hrtimer_cb_mode {
  */
 struct hrtimer {
 	struct rb_node			node;
-	ktime_t				expires;
+	ktime_t				_expires;
+	ktime_t				_softexpires;
 	enum hrtimer_restart		(*function)(struct hrtimer *);
 	struct hrtimer_clock_base	*base;
 	unsigned long			state;
@@ -201,6 +209,71 @@ struct hrtimer_cpu_base {
 #endif
 };
 
+static inline void hrtimer_set_expires(struct hrtimer *timer, ktime_t time)
+{
+	timer->_expires = time;
+	timer->_softexpires = time;
+}
+
+static inline void hrtimer_set_expires_range(struct hrtimer *timer, ktime_t time, ktime_t delta)
+{
+	timer->_softexpires = time;
+	timer->_expires = ktime_add_safe(time, delta);
+}
+
+static inline void hrtimer_set_expires_range_ns(struct hrtimer *timer, ktime_t time, unsigned long delta)
+{
+	timer->_softexpires = time;
+	timer->_expires = ktime_add_safe(time, ns_to_ktime(delta));
+}
+
+static inline void hrtimer_set_expires_tv64(struct hrtimer *timer, s64 tv64)
+{
+	timer->_expires.tv64 = tv64;
+	timer->_softexpires.tv64 = tv64;
+}
+
+static inline void hrtimer_add_expires(struct hrtimer *timer, ktime_t time)
+{
+	timer->_expires = ktime_add_safe(timer->_expires, time);
+	timer->_softexpires = ktime_add_safe(timer->_softexpires, time);
+}
+
+static inline void hrtimer_add_expires_ns(struct hrtimer *timer, unsigned long ns)
+{
+	timer->_expires = ktime_add_ns(timer->_expires, ns);
+	timer->_softexpires = ktime_add_ns(timer->_softexpires, ns);
+}
+
+static inline ktime_t hrtimer_get_expires(const struct hrtimer *timer)
+{
+	return timer->_expires;
+}
+
+static inline ktime_t hrtimer_get_softexpires(const struct hrtimer *timer)
+{
+	return timer->_softexpires;
+}
+
+static inline s64 hrtimer_get_expires_tv64(const struct hrtimer *timer)
+{
+	return timer->_expires.tv64;
+}
+static inline s64 hrtimer_get_softexpires_tv64(const struct hrtimer *timer)
+{
+	return timer->_softexpires.tv64;
+}
+
+static inline s64 hrtimer_get_expires_ns(const struct hrtimer *timer)
+{
+	return ktime_to_ns(timer->_expires);
+}
+
+static inline ktime_t hrtimer_expires_remaining(const struct hrtimer *timer)
+{
+    return ktime_sub(timer->_expires, timer->base->get_time());
+}
+
 #ifdef CONFIG_HIGH_RES_TIMERS
 struct clock_event_device;
 
@@ -221,6 +294,8 @@ static inline int hrtimer_is_hres_active(struct hrtimer *timer)
 	return timer->base->cpu_base->hres_active;
 }
 
+extern void hrtimer_peek_ahead_timers(void);
+
 /*
  * The resolution of the clocks. The resolution value is returned in
  * the clock_getres() system call to give application programmers an
@@ -243,6 +318,7 @@ static inline int hrtimer_is_hres_active(struct hrtimer *timer)
  * is expired in the next softirq when the clock was advanced.
  */
 static inline void clock_was_set(void) { }
+static inline void hrtimer_peek_ahead_timers(void) { }
 
 static inline void hres_timers_resume(void) { }
 
@@ -264,6 +340,10 @@ static inline int hrtimer_is_hres_active(struct hrtimer *timer)
 extern ktime_t ktime_get(void);
 extern ktime_t ktime_get_real(void);
 
+
+DECLARE_PER_CPU(struct tick_device, tick_cpu_device);
+
+
 /* Exported timer functions: */
 
 /* Initialize timers: */
@@ -288,12 +368,25 @@ static inline void destroy_hrtimer_on_stack(struct hrtimer *timer) { }
 /* Basic timer operations: */
 extern int hrtimer_start(struct hrtimer *timer, ktime_t tim,
 			 const enum hrtimer_mode mode);
+extern int hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
+			unsigned long range_ns, const enum hrtimer_mode mode);
 extern int hrtimer_cancel(struct hrtimer *timer);
 extern int hrtimer_try_to_cancel(struct hrtimer *timer);
 
+static inline int hrtimer_start_expires(struct hrtimer *timer,
+						enum hrtimer_mode mode)
+{
+	unsigned long delta;
+	ktime_t soft, hard;
+	soft = hrtimer_get_softexpires(timer);
+	hard = hrtimer_get_expires(timer);
+	delta = ktime_to_ns(ktime_sub(hard, soft));
+	return hrtimer_start_range_ns(timer, soft, delta, mode);
+}
+
 static inline int hrtimer_restart(struct hrtimer *timer)
 {
-	return hrtimer_start(timer, timer->expires, HRTIMER_MODE_ABS);
+	return hrtimer_start_expires(timer, HRTIMER_MODE_ABS);
 }
 
 /* Query timers: */
@@ -350,6 +443,10 @@ extern long hrtimer_nanosleep_restart(struct restart_block *restart_block);
 extern void hrtimer_init_sleeper(struct hrtimer_sleeper *sl,
 				 struct task_struct *tsk);
 
+extern int schedule_hrtimeout_range(ktime_t *expires, unsigned long delta,
+						const enum hrtimer_mode mode);
+extern int schedule_hrtimeout(ktime_t *expires, const enum hrtimer_mode mode);
+
 /* Soft interrupt function to run the hrtimer queues: */
 extern void hrtimer_run_queues(void);
 extern void hrtimer_run_pending(void);
diff --git a/include/linux/init_task.h b/include/linux/init_task.h
index 021d8e7..23fd890 100644
--- a/include/linux/init_task.h
+++ b/include/linux/init_task.h
@@ -170,6 +170,7 @@ extern struct group_info init_groups;
 	.cpu_timers	= INIT_CPU_TIMERS(tsk.cpu_timers),		\
 	.fs_excl	= ATOMIC_INIT(0),				\
 	.pi_lock	= __SPIN_LOCK_UNLOCKED(tsk.pi_lock),		\
+	.timer_slack_ns = 50000, /* 50 usec default slack */		\
 	.pids = {							\
 		[PIDTYPE_PID]  = INIT_PID_LINK(PIDTYPE_PID),		\
 		[PIDTYPE_PGID] = INIT_PID_LINK(PIDTYPE_PGID),		\
diff --git a/include/linux/poll.h b/include/linux/poll.h
index ef45382..badd98a 100644
--- a/include/linux/poll.h
+++ b/include/linux/poll.h
@@ -114,11 +114,13 @@ void zero_fd_set(unsigned long nr, unsigned long *fdset)
 
 #define MAX_INT64_SECONDS (((s64)(~((u64)0)>>1)/HZ)-1)
 
-extern int do_select(int n, fd_set_bits *fds, s64 *timeout);
+extern int do_select(int n, fd_set_bits *fds, struct timespec *end_time);
 extern int do_sys_poll(struct pollfd __user * ufds, unsigned int nfds,
-		       s64 *timeout);
+		       struct timespec *end_time);
 extern int core_sys_select(int n, fd_set __user *inp, fd_set __user *outp,
-			   fd_set __user *exp, s64 *timeout);
+			   fd_set __user *exp, struct timespec *end_time);
+
+extern int poll_select_set_timeout(struct timespec *to, long sec, long nsec);
 
 #endif /* KERNEL */
 
diff --git a/include/linux/prctl.h b/include/linux/prctl.h
index 5ad7919..48d887e 100644
--- a/include/linux/prctl.h
+++ b/include/linux/prctl.h
@@ -78,4 +78,11 @@
 #define PR_GET_SECUREBITS 27
 #define PR_SET_SECUREBITS 28
 
+/*
+ * Get/set the timerslack as used by poll/select/nanosleep
+ * A value of 0 means "use default"
+ */
+#define PR_SET_TIMERSLACK 29
+#define PR_GET_TIMERSLACK 30
+
 #endif /* _LINUX_PRCTL_H */
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 5c38db5..9ee3bed 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1346,6 +1346,12 @@ struct task_struct {
 	int latency_record_count;
 	struct latency_record latency_record[LT_SAVECOUNT];
 #endif
+	/*
+	 * time slack values; these are used to round up poll() and
+	 * select() etc timeout values. These are in nanoseconds.
+	 */
+	unsigned long timer_slack_ns;
+	unsigned long default_timer_slack_ns;
 };
 
 /*
diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h
index 38a5647..e6b820f 100644
--- a/include/linux/thread_info.h
+++ b/include/linux/thread_info.h
@@ -38,6 +38,14 @@ struct restart_block {
 #endif
 			u64 expires;
 		} nanosleep;
+		/* For poll */
+		struct {
+			struct pollfd __user *ufds;
+			int nfds;
+			int has_timeout;
+			unsigned long tv_sec;
+			unsigned long tv_nsec;
+		} poll;
 	};
 };
 
diff --git a/include/linux/time.h b/include/linux/time.h
index 4f1c9db..ce321ac 100644
--- a/include/linux/time.h
+++ b/include/linux/time.h
@@ -40,6 +40,8 @@ extern struct timezone sys_tz;
 #define NSEC_PER_SEC	1000000000L
 #define FSEC_PER_SEC	1000000000000000L
 
+#define TIME_T_MAX	(time_t)((1UL << ((sizeof(time_t) << 3) - 1)) - 1)
+
 static inline int timespec_equal(const struct timespec *a,
                                  const struct timespec *b)
 {
@@ -74,6 +76,8 @@ extern unsigned long mktime(const unsigned int year, const unsigned int mon,
 			    const unsigned int min, const unsigned int sec);
 
 extern void set_normalized_timespec(struct timespec *ts, time_t sec, long nsec);
+extern struct timespec timespec_add_safe(const struct timespec lhs,
+					 const struct timespec rhs);
 
 /*
  * sub = lhs - rhs, in normalized form
diff --git a/kernel/fork.c b/kernel/fork.c
index 4d09355..f608356 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1018,6 +1018,8 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 	p->prev_utime = cputime_zero;
 	p->prev_stime = cputime_zero;
 
+	p->default_timer_slack_ns = current->timer_slack_ns;
+
 #ifdef CONFIG_DETECT_SOFTLOCKUP
 	p->last_switch_count = 0;
 	p->last_switch_timestamp = 0;
diff --git a/kernel/futex.c b/kernel/futex.c
index 7d1136e..8af1002 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -1296,13 +1296,16 @@ static int futex_wait(u32 __user *uaddr, struct rw_semaphore *fshared,
 		if (!abs_time)
 			schedule();
 		else {
+			unsigned long slack;
+			slack = current->timer_slack_ns;
+			if (rt_task(current))
+				slack = 0;
 			hrtimer_init_on_stack(&t.timer, CLOCK_MONOTONIC,
 						HRTIMER_MODE_ABS);
 			hrtimer_init_sleeper(&t, current);
-			t.timer.expires = *abs_time;
+			hrtimer_set_expires_range_ns(&t.timer, *abs_time, slack);
 
-			hrtimer_start(&t.timer, t.timer.expires,
-						HRTIMER_MODE_ABS);
+			hrtimer_start_expires(&t.timer, HRTIMER_MODE_ABS);
 			if (!hrtimer_active(&t.timer))
 				t.task = NULL;
 
@@ -1404,7 +1407,7 @@ static int futex_lock_pi(u32 __user *uaddr, struct rw_semaphore *fshared,
 		hrtimer_init_on_stack(&to->timer, CLOCK_REALTIME,
 				      HRTIMER_MODE_ABS);
 		hrtimer_init_sleeper(to, current);
-		to->timer.expires = *time;
+		hrtimer_set_expires(&to->timer, *time);
 	}
 
 	q.pi_state = NULL;
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 95978f4..2b465df 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -517,7 +517,7 @@ static void hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base)
 		if (!base->first)
 			continue;
 		timer = rb_entry(base->first, struct hrtimer, node);
-		expires = ktime_sub(timer->expires, base->offset);
+		expires = ktime_sub(hrtimer_get_expires(timer), base->offset);
 		if (expires.tv64 < cpu_base->expires_next.tv64)
 			cpu_base->expires_next = expires;
 	}
@@ -539,10 +539,10 @@ static int hrtimer_reprogram(struct hrtimer *timer,
 			     struct hrtimer_clock_base *base)
 {
 	ktime_t *expires_next = &__get_cpu_var(hrtimer_bases).expires_next;
-	ktime_t expires = ktime_sub(timer->expires, base->offset);
+	ktime_t expires = ktime_sub(hrtimer_get_expires(timer), base->offset);
 	int res;
 
-	WARN_ON_ONCE(timer->expires.tv64 < 0);
+	WARN_ON_ONCE(hrtimer_get_expires_tv64(timer) < 0);
 
 	/*
 	 * When the callback is running, we do not reprogram the clock event
@@ -795,7 +795,7 @@ u64 hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval)
 	u64 orun = 1;
 	ktime_t delta;
 
-	delta = ktime_sub(now, timer->expires);
+	delta = ktime_sub(now, hrtimer_get_expires(timer));
 
 	if (delta.tv64 < 0)
 		return 0;
@@ -807,8 +807,8 @@ u64 hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval)
 		s64 incr = ktime_to_ns(interval);
 
 		orun = ktime_divns(delta, incr);
-		timer->expires = ktime_add_ns(timer->expires, incr * orun);
-		if (timer->expires.tv64 > now.tv64)
+		hrtimer_add_expires_ns(timer, incr * orun);
+		if (hrtimer_get_expires_tv64(timer) > now.tv64)
 			return orun;
 		/*
 		 * This (and the ktime_add() below) is the
@@ -816,7 +816,7 @@ u64 hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval)
 		 */
 		orun++;
 	}
-	timer->expires = ktime_add_safe(timer->expires, interval);
+	hrtimer_add_expires(timer, interval);
 
 	return orun;
 }
@@ -848,7 +848,8 @@ static void enqueue_hrtimer(struct hrtimer *timer,
 		 * We dont care about collisions. Nodes with
 		 * the same expiry time stay together.
 		 */
-		if (timer->expires.tv64 < entry->expires.tv64) {
+		if (hrtimer_get_expires_tv64(timer) <
+				hrtimer_get_expires_tv64(entry)) {
 			link = &(*link)->rb_left;
 		} else {
 			link = &(*link)->rb_right;
@@ -945,9 +946,10 @@ remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base)
 }
 
 /**
- * hrtimer_start - (re)start an relative timer on the current CPU
+ * hrtimer_start_range_ns - (re)start an hrtimer on the current CPU
  * @timer:	the timer to be added
  * @tim:	expiry time
+ * @delta_ns:	"slack" range for the timer
  * @mode:	expiry mode: absolute (HRTIMER_ABS) or relative (HRTIMER_REL)
  *
  * Returns:
@@ -955,7 +957,8 @@ remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base)
  *  1 when the timer was active
  */
 int
-hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode)
+hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, unsigned long delta_ns,
+			const enum hrtimer_mode mode)
 {
 	struct hrtimer_clock_base *base, *new_base;
 	unsigned long flags;
@@ -983,7 +986,7 @@ hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode)
 #endif
 	}
 
-	timer->expires = tim;
+	hrtimer_set_expires_range_ns(timer, tim, delta_ns);
 
 	timer_stats_hrtimer_set_start_info(timer);
 
@@ -1016,8 +1019,26 @@ hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode)
 
 	return ret;
 }
+EXPORT_SYMBOL_GPL(hrtimer_start_range_ns);
+
+/**
+ * hrtimer_start - (re)start an hrtimer on the current CPU
+ * @timer:	the timer to be added
+ * @tim:	expiry time
+ * @mode:	expiry mode: absolute (HRTIMER_ABS) or relative (HRTIMER_REL)
+ *
+ * Returns:
+ *  0 on success
+ *  1 when the timer was active
+ */
+int
+hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode)
+{
+	return hrtimer_start_range_ns(timer, tim, 0, mode);
+}
 EXPORT_SYMBOL_GPL(hrtimer_start);
 
+
 /**
  * hrtimer_try_to_cancel - try to deactivate a timer
  * @timer:	hrtimer to stop
@@ -1077,7 +1098,7 @@ ktime_t hrtimer_get_remaining(const struct hrtimer *timer)
 	ktime_t rem;
 
 	base = lock_hrtimer_base(timer, &flags);
-	rem = ktime_sub(timer->expires, base->get_time());
+	rem = hrtimer_expires_remaining(timer);
 	unlock_hrtimer_base(timer, &flags);
 
 	return rem;
@@ -1109,7 +1130,7 @@ ktime_t hrtimer_get_next_event(void)
 				continue;
 
 			timer = rb_entry(base->first, struct hrtimer, node);
-			delta.tv64 = timer->expires.tv64;
+			delta.tv64 = hrtimer_get_expires_tv64(timer);
 			delta = ktime_sub(delta, base->get_time());
 			if (delta.tv64 < mindelta.tv64)
 				mindelta.tv64 = delta.tv64;
@@ -1310,10 +1331,23 @@ void hrtimer_interrupt(struct clock_event_device *dev)
 
 			timer = rb_entry(node, struct hrtimer, node);
 
-			if (basenow.tv64 < timer->expires.tv64) {
+			/*
+			 * The immediate goal for using the softexpires is
+			 * minimizing wakeups, not running timers at the
+			 * earliest interrupt after their soft expiration.
+			 * This allows us to avoid using a Priority Search
+			 * Tree, which can answer a stabbing querry for
+			 * overlapping intervals and instead use the simple
+			 * BST we already have.
+			 * We don't add extra wakeups by delaying timers that
+			 * are right-of a not yet expired timer, because that
+			 * timer will have to trigger a wakeup anyway.
+			 */
+
+			if (basenow.tv64 < hrtimer_get_softexpires_tv64(timer)) {
 				ktime_t expires;
 
-				expires = ktime_sub(timer->expires,
+				expires = ktime_sub(hrtimer_get_expires(timer),
 						    base->offset);
 				if (expires.tv64 < expires_next.tv64)
 					expires_next = expires;
@@ -1349,6 +1383,30 @@ void hrtimer_interrupt(struct clock_event_device *dev)
 		raise_softirq(HRTIMER_SOFTIRQ);
 }
 
+/**
+ * hrtimer_peek_ahead_timers -- run soft-expired timers now
+ *
+ * hrtimer_peek_ahead_timers will peek at the timer queue of
+ * the current cpu and check if there are any timers for which
+ * the soft expires time has passed. If any such timers exist,
+ * they are run immediately and then removed from the timer queue.
+ *
+ */
+void hrtimer_peek_ahead_timers(void)
+{
+	struct tick_device *td;
+	unsigned long flags;
+
+	if (!hrtimer_hres_active())
+		return;
+
+	local_irq_save(flags);
+	td = &__get_cpu_var(tick_cpu_device);
+	if (td && td->evtdev)
+		hrtimer_interrupt(td->evtdev);
+	local_irq_restore(flags);
+}
+
 static void run_hrtimer_softirq(struct softirq_action *h)
 {
 	run_hrtimer_pending(&__get_cpu_var(hrtimer_bases));
@@ -1414,7 +1472,8 @@ void hrtimer_run_queues(void)
 			struct hrtimer *timer;
 
 			timer = rb_entry(node, struct hrtimer, node);
-			if (base->softirq_time.tv64 <= timer->expires.tv64)
+			if (base->softirq_time.tv64 <=
+					hrtimer_get_expires_tv64(timer))
 				break;
 
 			if (timer->cb_mode == HRTIMER_CB_SOFTIRQ) {
@@ -1462,7 +1521,7 @@ static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mod
 
 	do {
 		set_current_state(TASK_INTERRUPTIBLE);
-		hrtimer_start(&t->timer, t->timer.expires, mode);
+		hrtimer_start_expires(&t->timer, mode);
 		if (!hrtimer_active(&t->timer))
 			t->task = NULL;
 
@@ -1484,7 +1543,7 @@ static int update_rmtp(struct hrtimer *timer, struct timespec __user *rmtp)
 	struct timespec rmt;
 	ktime_t rem;
 
-	rem = ktime_sub(timer->expires, timer->base->get_time());
+	rem = hrtimer_expires_remaining(timer);
 	if (rem.tv64 <= 0)
 		return 0;
 	rmt = ktime_to_timespec(rem);
@@ -1503,7 +1562,7 @@ long __sched hrtimer_nanosleep_restart(struct restart_block *restart)
 
 	hrtimer_init_on_stack(&t.timer, restart->nanosleep.index,
 				HRTIMER_MODE_ABS);
-	t.timer.expires.tv64 = restart->nanosleep.expires;
+	hrtimer_set_expires_tv64(&t.timer, restart->nanosleep.expires);
 
 	if (do_nanosleep(&t, HRTIMER_MODE_ABS))
 		goto out;
@@ -1528,9 +1587,14 @@ long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp,
 	struct restart_block *restart;
 	struct hrtimer_sleeper t;
 	int ret = 0;
+	unsigned long slack;
+
+	slack = current->timer_slack_ns;
+	if (rt_task(current))
+		slack = 0;
 
 	hrtimer_init_on_stack(&t.timer, clockid, mode);
-	t.timer.expires = timespec_to_ktime(*rqtp);
+	hrtimer_set_expires_range_ns(&t.timer, timespec_to_ktime(*rqtp), slack);
 	if (do_nanosleep(&t, mode))
 		goto out;
 
@@ -1550,7 +1614,7 @@ long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp,
 	restart->fn = hrtimer_nanosleep_restart;
 	restart->nanosleep.index = t.timer.base->index;
 	restart->nanosleep.rmtp = rmtp;
-	restart->nanosleep.expires = t.timer.expires.tv64;
+	restart->nanosleep.expires = hrtimer_get_expires_tv64(&t.timer);
 
 	ret = -ERESTART_RESTARTBLOCK;
 out:
@@ -1752,3 +1816,103 @@ void __init hrtimers_init(void)
 #endif
 }
 
+/**
+ * schedule_hrtimeout_range - sleep until timeout
+ * @expires:	timeout value (ktime_t)
+ * @delta:	slack in expires timeout (ktime_t)
+ * @mode:	timer mode, HRTIMER_MODE_ABS or HRTIMER_MODE_REL
+ *
+ * Make the current task sleep until the given expiry time has
+ * elapsed. The routine will return immediately unless
+ * the current task state has been set (see set_current_state()).
+ *
+ * The @delta argument gives the kernel the freedom to schedule the
+ * actual wakeup to a time that is both power and performance friendly.
+ * The kernel give the normal best effort behavior for "@expires+@delta",
+ * but may decide to fire the timer earlier, but no earlier than @expires.
+ *
+ * You can set the task state as follows -
+ *
+ * %TASK_UNINTERRUPTIBLE - at least @timeout time is guaranteed to
+ * pass before the routine returns.
+ *
+ * %TASK_INTERRUPTIBLE - the routine may return early if a signal is
+ * delivered to the current task.
+ *
+ * The current task state is guaranteed to be TASK_RUNNING when this
+ * routine returns.
+ *
+ * Returns 0 when the timer has expired otherwise -EINTR
+ */
+int __sched schedule_hrtimeout_range(ktime_t *expires, unsigned long delta,
+			       const enum hrtimer_mode mode)
+{
+	struct hrtimer_sleeper t;
+
+	/*
+	 * Optimize when a zero timeout value is given. It does not
+	 * matter whether this is an absolute or a relative time.
+	 */
+	if (expires && !expires->tv64) {
+		__set_current_state(TASK_RUNNING);
+		return 0;
+	}
+
+	/*
+	 * A NULL parameter means "inifinte"
+	 */
+	if (!expires) {
+		schedule();
+		__set_current_state(TASK_RUNNING);
+		return -EINTR;
+	}
+
+	hrtimer_init_on_stack(&t.timer, CLOCK_MONOTONIC, mode);
+	hrtimer_set_expires_range_ns(&t.timer, *expires, delta);
+
+	hrtimer_init_sleeper(&t, current);
+
+	hrtimer_start_expires(&t.timer, mode);
+	if (!hrtimer_active(&t.timer))
+		t.task = NULL;
+
+	if (likely(t.task))
+		schedule();
+
+	hrtimer_cancel(&t.timer);
+	destroy_hrtimer_on_stack(&t.timer);
+
+	__set_current_state(TASK_RUNNING);
+
+	return !t.task ? 0 : -EINTR;
+}
+EXPORT_SYMBOL_GPL(schedule_hrtimeout_range);
+
+/**
+ * schedule_hrtimeout - sleep until timeout
+ * @expires:	timeout value (ktime_t)
+ * @mode:	timer mode, HRTIMER_MODE_ABS or HRTIMER_MODE_REL
+ *
+ * Make the current task sleep until the given expiry time has
+ * elapsed. The routine will return immediately unless
+ * the current task state has been set (see set_current_state()).
+ *
+ * You can set the task state as follows -
+ *
+ * %TASK_UNINTERRUPTIBLE - at least @timeout time is guaranteed to
+ * pass before the routine returns.
+ *
+ * %TASK_INTERRUPTIBLE - the routine may return early if a signal is
+ * delivered to the current task.
+ *
+ * The current task state is guaranteed to be TASK_RUNNING when this
+ * routine returns.
+ *
+ * Returns 0 when the timer has expired otherwise -EINTR
+ */
+int __sched schedule_hrtimeout(ktime_t *expires,
+			       const enum hrtimer_mode mode)
+{
+	return schedule_hrtimeout_range(expires, 0, mode);
+}
+EXPORT_SYMBOL_GPL(schedule_hrtimeout);
diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c
index b931d7c..5e79c66 100644
--- a/kernel/posix-timers.c
+++ b/kernel/posix-timers.c
@@ -639,7 +639,7 @@ common_timer_get(struct k_itimer *timr, struct itimerspec *cur_setting)
 	    (timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE))
 		timr->it_overrun += (unsigned int) hrtimer_forward(timer, now, iv);
 
-	remaining = ktime_sub(timer->expires, now);
+	remaining = ktime_sub(hrtimer_get_expires(timer), now);
 	/* Return 0 only, when the timer is expired and not pending */
 	if (remaining.tv64 <= 0) {
 		/*
@@ -733,7 +733,7 @@ common_timer_set(struct k_itimer *timr, int flags,
 	hrtimer_init(&timr->it.real.timer, timr->it_clock, mode);
 	timr->it.real.timer.function = posix_timer_fn;
 
-	timer->expires = timespec_to_ktime(new_setting->it_value);
+	hrtimer_set_expires(timer, timespec_to_ktime(new_setting->it_value));
 
 	/* Convert interval */
 	timr->it.real.interval = timespec_to_ktime(new_setting->it_interval);
@@ -742,14 +742,12 @@ common_timer_set(struct k_itimer *timr, int flags,
 	if (((timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE)) {
 		/* Setup correct expiry time for relative timers */
 		if (mode == HRTIMER_MODE_REL) {
-			timer->expires =
-				ktime_add_safe(timer->expires,
-					       timer->base->get_time());
+			hrtimer_add_expires(timer, timer->base->get_time());
 		}
 		return 0;
 	}
 
-	hrtimer_start(timer, timer->expires, mode);
+	hrtimer_start_expires(timer, mode);
 	return 0;
 }
 
diff --git a/kernel/rtmutex.c b/kernel/rtmutex.c
index 6522ae5..69d9cb9 100644
--- a/kernel/rtmutex.c
+++ b/kernel/rtmutex.c
@@ -631,8 +631,7 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state,
 
 	/* Setup the timer, when timeout != NULL */
 	if (unlikely(timeout)) {
-		hrtimer_start(&timeout->timer, timeout->timer.expires,
-			      HRTIMER_MODE_ABS);
+		hrtimer_start_expires(&timeout->timer, HRTIMER_MODE_ABS);
 		if (!hrtimer_active(&timeout->timer))
 			timeout->task = NULL;
 	}
diff --git a/kernel/sched.c b/kernel/sched.c
index d906f72..bfa87918 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -227,9 +227,8 @@ static void start_rt_bandwidth(struct rt_bandwidth *rt_b)
 
 		now = hrtimer_cb_get_time(&rt_b->rt_period_timer);
 		hrtimer_forward(&rt_b->rt_period_timer, now, rt_b->rt_period);
-		hrtimer_start(&rt_b->rt_period_timer,
-			      rt_b->rt_period_timer.expires,
-			      HRTIMER_MODE_ABS);
+		hrtimer_start_expires(&rt_b->rt_period_timer,
+				HRTIMER_MODE_ABS);
 	}
 	spin_unlock(&rt_b->rt_runtime_lock);
 }
@@ -1064,7 +1063,7 @@ static void hrtick_start(struct rq *rq, u64 delay)
 	struct hrtimer *timer = &rq->hrtick_timer;
 	ktime_t time = ktime_add_ns(timer->base->get_time(), delay);
 
-	timer->expires = time;
+	hrtimer_set_expires(timer, time);
 
 	if (rq == this_rq()) {
 		hrtimer_restart(timer);
diff --git a/kernel/sys.c b/kernel/sys.c
index 53879cd..31deba8 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1716,6 +1716,16 @@ asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3,
 		case PR_SET_TSC:
 			error = SET_TSC_CTL(arg2);
 			break;
+		case PR_GET_TIMERSLACK:
+			error = current->timer_slack_ns;
+			break;
+		case PR_SET_TIMERSLACK:
+			if (arg2 <= 0)
+				current->timer_slack_ns =
+					current->default_timer_slack_ns;
+			else
+				current->timer_slack_ns = arg2;
+			break;
 		default:
 			error = -EINVAL;
 			break;
diff --git a/kernel/time.c b/kernel/time.c
index 6a08660..d63a433 100644
--- a/kernel/time.c
+++ b/kernel/time.c
@@ -669,3 +669,21 @@ EXPORT_SYMBOL(get_jiffies_64);
 #endif
 
 EXPORT_SYMBOL(jiffies);
+
+/*
+ * Add two timespec values and do a safety check for overflow.
+ * It's assumed that both values are valid (>= 0)
+ */
+struct timespec timespec_add_safe(const struct timespec lhs,
+				  const struct timespec rhs)
+{
+	struct timespec res;
+
+	set_normalized_timespec(&res, lhs.tv_sec + rhs.tv_sec,
+				lhs.tv_nsec + rhs.tv_nsec);
+
+	if (res.tv_sec < lhs.tv_sec || res.tv_sec < rhs.tv_sec)
+		res.tv_sec = TIME_T_MAX;
+
+	return res;
+}
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index 1a20715..8ff15e5 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -142,8 +142,7 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
 		time_state = TIME_OOP;
 		printk(KERN_NOTICE "Clock: "
 		       "inserting leap second 23:59:60 UTC\n");
-		leap_timer.expires = ktime_add_ns(leap_timer.expires,
-						  NSEC_PER_SEC);
+		hrtimer_add_expires_ns(&leap_timer, NSEC_PER_SEC);
 		res = HRTIMER_RESTART;
 		break;
 	case TIME_DEL:
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 727c1ae..5bbb104 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -300,7 +300,7 @@ void tick_nohz_stop_sched_tick(int inidle)
 				goto out;
 			}
 
-			ts->idle_tick = ts->sched_timer.expires;
+			ts->idle_tick = hrtimer_get_expires(&ts->sched_timer);
 			ts->tick_stopped = 1;
 			ts->idle_jiffies = last_jiffies;
 			rcu_enter_nohz();
@@ -380,21 +380,21 @@ ktime_t tick_nohz_get_sleep_length(void)
 static void tick_nohz_restart(struct tick_sched *ts, ktime_t now)
 {
 	hrtimer_cancel(&ts->sched_timer);
-	ts->sched_timer.expires = ts->idle_tick;
+	hrtimer_set_expires(&ts->sched_timer, ts->idle_tick);
 
 	while (1) {
 		/* Forward the time to expire in the future */
 		hrtimer_forward(&ts->sched_timer, now, tick_period);
 
 		if (ts->nohz_mode == NOHZ_MODE_HIGHRES) {
-			hrtimer_start(&ts->sched_timer,
-				      ts->sched_timer.expires,
+			hrtimer_start_expires(&ts->sched_timer,
 				      HRTIMER_MODE_ABS);
 			/* Check, if the timer was already in the past */
 			if (hrtimer_active(&ts->sched_timer))
 				break;
 		} else {
-			if (!tick_program_event(ts->sched_timer.expires, 0))
+			if (!tick_program_event(
+				hrtimer_get_expires(&ts->sched_timer), 0))
 				break;
 		}
 		/* Update jiffies and reread time */
@@ -456,14 +456,16 @@ void tick_nohz_restart_sched_tick(void)
 	 */
 	ts->tick_stopped  = 0;
 	ts->idle_exittime = now;
+
 	tick_nohz_restart(ts, now);
+
 	local_irq_enable();
 }
 
 static int tick_nohz_reprogram(struct tick_sched *ts, ktime_t now)
 {
 	hrtimer_forward(&ts->sched_timer, now, tick_period);
-	return tick_program_event(ts->sched_timer.expires, 0);
+	return tick_program_event(hrtimer_get_expires(&ts->sched_timer), 0);
 }
 
 /*
@@ -542,7 +544,7 @@ static void tick_nohz_switch_to_nohz(void)
 	next = tick_init_jiffy_update();
 
 	for (;;) {
-		ts->sched_timer.expires = next;
+		hrtimer_set_expires(&ts->sched_timer, next);
 		if (!tick_program_event(next, 0))
 			break;
 		next = ktime_add(next, tick_period);
@@ -577,7 +579,7 @@ static void tick_nohz_kick_tick(int cpu)
 	 * already reached or less/equal than the tick period.
 	 */
 	now = ktime_get();
-	delta =	ktime_sub(ts->sched_timer.expires, now);
+	delta =	ktime_sub(hrtimer_get_expires(&ts->sched_timer), now);
 	if (delta.tv64 <= tick_period.tv64)
 		return;
 
@@ -678,16 +680,15 @@ void tick_setup_sched_timer(void)
 	ts->sched_timer.cb_mode = HRTIMER_CB_IRQSAFE_PERCPU;
 
 	/* Get the next period (per cpu) */
-	ts->sched_timer.expires = tick_init_jiffy_update();
+	hrtimer_set_expires(&ts->sched_timer, tick_init_jiffy_update());
 	offset = ktime_to_ns(tick_period) >> 1;
 	do_div(offset, num_possible_cpus());
 	offset *= smp_processor_id();
-	ts->sched_timer.expires = ktime_add_ns(ts->sched_timer.expires, offset);
+	hrtimer_add_expires_ns(&ts->sched_timer, offset);
 
 	for (;;) {
 		hrtimer_forward(&ts->sched_timer, now, tick_period);
-		hrtimer_start(&ts->sched_timer, ts->sched_timer.expires,
-			      HRTIMER_MODE_ABS);
+		hrtimer_start_expires(&ts->sched_timer, HRTIMER_MODE_ABS);
 		/* Check, if the timer was already in the past */
 		if (hrtimer_active(&ts->sched_timer))
 			break;
diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c
index f642691..a999b92 100644
--- a/kernel/time/timer_list.c
+++ b/kernel/time/timer_list.c
@@ -66,9 +66,11 @@ print_timer(struct seq_file *m, struct hrtimer *taddr, struct hrtimer *timer,
 	SEQ_printf(m, ", %s/%d", tmp, timer->start_pid);
 #endif
 	SEQ_printf(m, "\n");
-	SEQ_printf(m, " # expires at %Lu nsecs [in %Ld nsecs]\n",
-		(unsigned long long)ktime_to_ns(timer->expires),
-		(long long)(ktime_to_ns(timer->expires) - now));
+	SEQ_printf(m, " # expires at %Lu-%Lu nsecs [in %Ld to %Ld nsecs]\n",
+		(unsigned long long)ktime_to_ns(hrtimer_get_softexpires(timer)),
+		(unsigned long long)ktime_to_ns(hrtimer_get_expires(timer)),
+		(long long)(ktime_to_ns(hrtimer_get_softexpires(timer)) - now),
+		(long long)(ktime_to_ns(hrtimer_get_expires(timer)) - now));
 }
 
 static void
diff --git a/net/sched/sch_cbq.c b/net/sched/sch_cbq.c
index 8b06fa9..03e389e 100644
--- a/net/sched/sch_cbq.c
+++ b/net/sched/sch_cbq.c
@@ -545,9 +545,10 @@ static void cbq_ovl_delay(struct cbq_class *cl)
 			expires = ktime_set(0, 0);
 			expires = ktime_add_ns(expires, PSCHED_US2NS(sched));
 			if (hrtimer_try_to_cancel(&q->delay_timer) &&
-			    ktime_to_ns(ktime_sub(q->delay_timer.expires,
-						  expires)) > 0)
-				q->delay_timer.expires = expires;
+			    ktime_to_ns(ktime_sub(
+					hrtimer_get_expires(&q->delay_timer),
+					expires)) > 0)
+				hrtimer_set_expires(&q->delay_timer, expires);
 			hrtimer_restart(&q->delay_timer);
 			cl->delayed = 1;
 			cl->xstats.overactions++;
diff --git a/sound/drivers/pcsp/pcsp_lib.c b/sound/drivers/pcsp/pcsp_lib.c
index e341f3f..1f42e40 100644
--- a/sound/drivers/pcsp/pcsp_lib.c
+++ b/sound/drivers/pcsp/pcsp_lib.c
@@ -34,7 +34,7 @@ enum hrtimer_restart pcsp_do_timer(struct hrtimer *handle)
 		chip->thalf = 0;
 		if (!atomic_read(&chip->timer_active))
 			return HRTIMER_NORESTART;
-		hrtimer_forward(&chip->timer, chip->timer.expires,
+		hrtimer_forward(&chip->timer, hrtimer_get_expires(&chip->timer),
 				ktime_set(0, chip->ns_rem));
 		return HRTIMER_RESTART;
 	}
@@ -118,7 +118,8 @@ enum hrtimer_restart pcsp_do_timer(struct hrtimer *handle)
 	chip->ns_rem = PCSP_PERIOD_NS();
 	ns = (chip->thalf ? PCSP_CALC_NS(timer_cnt) : chip->ns_rem);
 	chip->ns_rem -= ns;
-	hrtimer_forward(&chip->timer, chip->timer.expires, ktime_set(0, ns));
+	hrtimer_forward(&chip->timer, hrtimer_get_expires(&chip->timer),
+							ktime_set(0, ns));
 	return HRTIMER_RESTART;
 
 exit_nr_unlock2: