diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/compat.c | 24 | ||||
| -rw-r--r-- | kernel/irq/chip.c | 1 | ||||
| -rw-r--r-- | kernel/rcu/tree.h | 2 | ||||
| -rw-r--r-- | kernel/rcu/tree_plugin.h | 22 | ||||
| -rw-r--r-- | kernel/time/tick-sched.c | 14 | ||||
| -rw-r--r-- | kernel/time/timekeeping.c | 5 |
6 files changed, 51 insertions, 17 deletions
diff --git a/kernel/compat.c b/kernel/compat.c index 633394f442f8..ebb3c369d03d 100644 --- a/kernel/compat.c +++ b/kernel/compat.c @@ -226,7 +226,7 @@ static long compat_nanosleep_restart(struct restart_block *restart) ret = hrtimer_nanosleep_restart(restart); set_fs(oldfs); - if (ret) { + if (ret == -ERESTART_RESTARTBLOCK) { rmtp = restart->nanosleep.compat_rmtp; if (rmtp && compat_put_timespec(&rmt, rmtp)) @@ -256,7 +256,26 @@ COMPAT_SYSCALL_DEFINE2(nanosleep, struct compat_timespec __user *, rqtp, HRTIMER_MODE_REL, CLOCK_MONOTONIC); set_fs(oldfs); - if (ret) { + /* + * hrtimer_nanosleep() can only return 0 or + * -ERESTART_RESTARTBLOCK here because: + * + * - we call it with HRTIMER_MODE_REL and therefor exclude the + * -ERESTARTNOHAND return path. + * + * - we supply the rmtp argument from the task stack (due to + * the necessary compat conversion. So the update cannot + * fail, which excludes the -EFAULT return path as well. If + * it fails nevertheless we have a bigger problem and wont + * reach this place anymore. + * + * - if the return value is 0, we do not have to update rmtp + * because there is no remaining time. + * + * We check for -ERESTART_RESTARTBLOCK nevertheless if the + * core implementation decides to return random nonsense. + */ + if (ret == -ERESTART_RESTARTBLOCK) { struct restart_block *restart = ¤t_thread_info()->restart_block; @@ -266,7 +285,6 @@ COMPAT_SYSCALL_DEFINE2(nanosleep, struct compat_timespec __user *, rqtp, if (rmtp && compat_put_timespec(&rmt, rmtp)) return -EFAULT; } - return ret; } diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index a2b28a2fd7b1..6223fab9a9d2 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -517,6 +517,7 @@ out: chip->irq_eoi(&desc->irq_data); raw_spin_unlock(&desc->lock); } +EXPORT_SYMBOL_GPL(handle_fasteoi_irq); /** * handle_edge_irq - edge type IRQ handler diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h index 71e64c718f75..6a86eb7bac45 100644 --- a/kernel/rcu/tree.h +++ b/kernel/rcu/tree.h @@ -358,7 +358,7 @@ struct rcu_data { struct rcu_head **nocb_gp_tail; long nocb_gp_count; long nocb_gp_count_lazy; - bool nocb_leader_wake; /* Is the nocb leader thread awake? */ + bool nocb_leader_sleep; /* Is the nocb leader thread asleep? */ struct rcu_data *nocb_next_follower; /* Next follower in wakeup chain. */ diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 00dc411e9676..a7997e272564 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -2074,9 +2074,9 @@ static void wake_nocb_leader(struct rcu_data *rdp, bool force) if (!ACCESS_ONCE(rdp_leader->nocb_kthread)) return; - if (!ACCESS_ONCE(rdp_leader->nocb_leader_wake) || force) { + if (ACCESS_ONCE(rdp_leader->nocb_leader_sleep) || force) { /* Prior xchg orders against prior callback enqueue. */ - ACCESS_ONCE(rdp_leader->nocb_leader_wake) = true; + ACCESS_ONCE(rdp_leader->nocb_leader_sleep) = false; wake_up(&rdp_leader->nocb_wq); } } @@ -2253,7 +2253,7 @@ wait_again: if (!rcu_nocb_poll) { trace_rcu_nocb_wake(my_rdp->rsp->name, my_rdp->cpu, "Sleep"); wait_event_interruptible(my_rdp->nocb_wq, - ACCESS_ONCE(my_rdp->nocb_leader_wake)); + !ACCESS_ONCE(my_rdp->nocb_leader_sleep)); /* Memory barrier handled by smp_mb() calls below and repoll. */ } else if (firsttime) { firsttime = false; /* Don't drown trace log with "Poll"! */ @@ -2292,12 +2292,12 @@ wait_again: schedule_timeout_interruptible(1); /* Rescan in case we were a victim of memory ordering. */ - my_rdp->nocb_leader_wake = false; - smp_mb(); /* Ensure _wake false before scan. */ + my_rdp->nocb_leader_sleep = true; + smp_mb(); /* Ensure _sleep true before scan. */ for (rdp = my_rdp; rdp; rdp = rdp->nocb_next_follower) if (ACCESS_ONCE(rdp->nocb_head)) { /* Found CB, so short-circuit next wait. */ - my_rdp->nocb_leader_wake = true; + my_rdp->nocb_leader_sleep = false; break; } goto wait_again; @@ -2307,17 +2307,17 @@ wait_again: rcu_nocb_wait_gp(my_rdp); /* - * We left ->nocb_leader_wake set to reduce cache thrashing. - * We clear it now, but recheck for new callbacks while + * We left ->nocb_leader_sleep unset to reduce cache thrashing. + * We set it now, but recheck for new callbacks while * traversing our follower list. */ - my_rdp->nocb_leader_wake = false; - smp_mb(); /* Ensure _wake false before scan of ->nocb_head. */ + my_rdp->nocb_leader_sleep = true; + smp_mb(); /* Ensure _sleep true before scan of ->nocb_head. */ /* Each pass through the following loop wakes a follower, if needed. */ for (rdp = my_rdp; rdp; rdp = rdp->nocb_next_follower) { if (ACCESS_ONCE(rdp->nocb_head)) - my_rdp->nocb_leader_wake = true; /* No need to wait. */ + my_rdp->nocb_leader_sleep = false;/* No need to sleep.*/ if (!rdp->nocb_gp_head) continue; /* No CBs, so no need to wake follower. */ diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 99aa6ee3908f..f654a8a298fa 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -225,6 +225,20 @@ static DEFINE_PER_CPU(struct irq_work, nohz_full_kick_work) = { }; /* + * Kick this CPU if it's full dynticks in order to force it to + * re-evaluate its dependency on the tick and restart it if necessary. + * This kick, unlike tick_nohz_full_kick_cpu() and tick_nohz_full_kick_all(), + * is NMI safe. + */ +void tick_nohz_full_kick(void) +{ + if (!tick_nohz_full_cpu(smp_processor_id())) + return; + + irq_work_queue(&__get_cpu_var(nohz_full_kick_work)); +} + +/* * Kick the CPU if it's full dynticks in order to force it to * re-evaluate its dependency on the tick and restart it if necessary. */ diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index fb4a9c2cf8d9..ec1791fae965 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -442,11 +442,12 @@ static void timekeeping_update(struct timekeeper *tk, unsigned int action) tk->ntp_error = 0; ntp_clear(); } - update_vsyscall(tk); - update_pvclock_gtod(tk, action & TK_CLOCK_WAS_SET); tk_update_ktime_data(tk); + update_vsyscall(tk); + update_pvclock_gtod(tk, action & TK_CLOCK_WAS_SET); + if (action & TK_MIRROR) memcpy(&shadow_timekeeper, &tk_core.timekeeper, sizeof(tk_core.timekeeper)); |