diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/cpuset.c | 25 | ||||
| -rw-r--r-- | kernel/exit.c | 8 | ||||
| -rw-r--r-- | kernel/hrtimer.c | 6 | ||||
| -rw-r--r-- | kernel/posix-cpu-timers.c | 48 | ||||
| -rw-r--r-- | kernel/power/main.c | 2 | ||||
| -rw-r--r-- | kernel/printk.c | 28 | ||||
| -rw-r--r-- | kernel/sched.c | 62 | ||||
| -rw-r--r-- | kernel/timer.c | 16 |
8 files changed, 107 insertions, 88 deletions
diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 72248d1b9e3..ab81fdd4572 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -2231,19 +2231,25 @@ static const struct cpuset *nearest_exclusive_ancestor(const struct cpuset *cs) * So only GFP_KERNEL allocations, if all nodes in the cpuset are * short of memory, might require taking the callback_mutex mutex. * - * The first loop over the zonelist in mm/page_alloc.c:__alloc_pages() - * calls here with __GFP_HARDWALL always set in gfp_mask, enforcing - * hardwall cpusets - no allocation on a node outside the cpuset is - * allowed (unless in interrupt, of course). - * - * The second loop doesn't even call here for GFP_ATOMIC requests - * (if the __alloc_pages() local variable 'wait' is set). That check - * and the checks below have the combined affect in the second loop of - * the __alloc_pages() routine that: + * The first call here from mm/page_alloc:get_page_from_freelist() + * has __GFP_HARDWALL set in gfp_mask, enforcing hardwall cpusets, so + * no allocation on a node outside the cpuset is allowed (unless in + * interrupt, of course). + * + * The second pass through get_page_from_freelist() doesn't even call + * here for GFP_ATOMIC calls. For those calls, the __alloc_pages() + * variable 'wait' is not set, and the bit ALLOC_CPUSET is not set + * in alloc_flags. That logic and the checks below have the combined + * affect that: * in_interrupt - any node ok (current task context irrelevant) * GFP_ATOMIC - any node ok * GFP_KERNEL - any node in enclosing mem_exclusive cpuset ok * GFP_USER - only nodes in current tasks mems allowed ok. + * + * Rule: + * Don't call cpuset_zone_allowed() if you can't sleep, unless you + * pass in the __GFP_HARDWALL flag set in gfp_flag, which disables + * the code that might scan up ancestor cpusets and sleep. **/ int __cpuset_zone_allowed(struct zone *z, gfp_t gfp_mask) @@ -2255,6 +2261,7 @@ int __cpuset_zone_allowed(struct zone *z, gfp_t gfp_mask) if (in_interrupt()) return 1; node = z->zone_pgdat->node_id; + might_sleep_if(!(gfp_mask & __GFP_HARDWALL)); if (node_isset(node, current->mems_allowed)) return 1; if (gfp_mask & __GFP_HARDWALL) /* If hardwall request, stop here */ diff --git a/kernel/exit.c b/kernel/exit.c index e95b9328221..e06d0c10a24 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -881,14 +881,6 @@ fastcall NORET_TYPE void do_exit(long code) tsk->flags |= PF_EXITING; - /* - * Make sure we don't try to process any timer firings - * while we are already exiting. - */ - tsk->it_virt_expires = cputime_zero; - tsk->it_prof_expires = cputime_zero; - tsk->it_sched_expires = 0; - if (unlikely(in_atomic())) printk(KERN_INFO "note: %s[%d] exited with preempt_count %d\n", current->comm, current->pid, diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index b7f0388bd71..01fa2ae98a8 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -456,6 +456,7 @@ hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode) return ret; } +EXPORT_SYMBOL_GPL(hrtimer_start); /** * hrtimer_try_to_cancel - try to deactivate a timer @@ -484,6 +485,7 @@ int hrtimer_try_to_cancel(struct hrtimer *timer) return ret; } +EXPORT_SYMBOL_GPL(hrtimer_try_to_cancel); /** * hrtimer_cancel - cancel a timer and wait for the handler to finish. @@ -504,6 +506,7 @@ int hrtimer_cancel(struct hrtimer *timer) cpu_relax(); } } +EXPORT_SYMBOL_GPL(hrtimer_cancel); /** * hrtimer_get_remaining - get remaining time for the timer @@ -522,6 +525,7 @@ ktime_t hrtimer_get_remaining(const struct hrtimer *timer) return rem; } +EXPORT_SYMBOL_GPL(hrtimer_get_remaining); #ifdef CONFIG_NO_IDLE_HZ /** @@ -580,6 +584,7 @@ void hrtimer_init(struct hrtimer *timer, clockid_t clock_id, timer->base = &bases[clock_id]; timer->node.rb_parent = HRTIMER_INACTIVE; } +EXPORT_SYMBOL_GPL(hrtimer_init); /** * hrtimer_get_res - get the timer resolution for a clock @@ -599,6 +604,7 @@ int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp) return 0; } +EXPORT_SYMBOL_GPL(hrtimer_get_res); /* * Expire the per base hrtimer-queue: diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index 520f6c59948..d38d9ec3276 100644 --- a/kernel/posix-cpu-timers.c +++ b/kernel/posix-cpu-timers.c @@ -555,9 +555,6 @@ static void arm_timer(struct k_itimer *timer, union cpu_time_count now) struct cpu_timer_list *next; unsigned long i; - if (CPUCLOCK_PERTHREAD(timer->it_clock) && (p->flags & PF_EXITING)) - return; - head = (CPUCLOCK_PERTHREAD(timer->it_clock) ? p->cpu_timers : p->signal->cpu_timers); head += CPUCLOCK_WHICH(timer->it_clock); @@ -1173,6 +1170,9 @@ static void check_process_timers(struct task_struct *tsk, } t = tsk; do { + if (unlikely(t->flags & PF_EXITING)) + continue; + ticks = cputime_add(cputime_add(t->utime, t->stime), prof_left); if (!cputime_eq(prof_expires, cputime_zero) && @@ -1193,11 +1193,7 @@ static void check_process_timers(struct task_struct *tsk, t->it_sched_expires > sched)) { t->it_sched_expires = sched; } - - do { - t = next_thread(t); - } while (unlikely(t->flags & PF_EXITING)); - } while (t != tsk); + } while ((t = next_thread(t)) != tsk); } } @@ -1289,30 +1285,30 @@ void run_posix_cpu_timers(struct task_struct *tsk) #undef UNEXPIRED - BUG_ON(tsk->exit_state); - /* * Double-check with locks held. */ read_lock(&tasklist_lock); - spin_lock(&tsk->sighand->siglock); + if (likely(tsk->signal != NULL)) { + spin_lock(&tsk->sighand->siglock); - /* - * Here we take off tsk->cpu_timers[N] and tsk->signal->cpu_timers[N] - * all the timers that are firing, and put them on the firing list. - */ - check_thread_timers(tsk, &firing); - check_process_timers(tsk, &firing); + /* + * Here we take off tsk->cpu_timers[N] and tsk->signal->cpu_timers[N] + * all the timers that are firing, and put them on the firing list. + */ + check_thread_timers(tsk, &firing); + check_process_timers(tsk, &firing); - /* - * We must release these locks before taking any timer's lock. - * There is a potential race with timer deletion here, as the - * siglock now protects our private firing list. We have set - * the firing flag in each timer, so that a deletion attempt - * that gets the timer lock before we do will give it up and - * spin until we've taken care of that timer below. - */ - spin_unlock(&tsk->sighand->siglock); + /* + * We must release these locks before taking any timer's lock. + * There is a potential race with timer deletion here, as the + * siglock now protects our private firing list. We have set + * the firing flag in each timer, so that a deletion attempt + * that gets the timer lock before we do will give it up and + * spin until we've taken care of that timer below. + */ + spin_unlock(&tsk->sighand->siglock); + } read_unlock(&tasklist_lock); /* diff --git a/kernel/power/main.c b/kernel/power/main.c index a6d9ef46009..0a907f0dc56 100644 --- a/kernel/power/main.c +++ b/kernel/power/main.c @@ -86,6 +86,7 @@ static int suspend_prepare(suspend_state_t state) goto Thaw; } + suspend_console(); if ((error = device_suspend(PMSG_SUSPEND))) { printk(KERN_ERR "Some devices failed to suspend\n"); goto Finish; @@ -133,6 +134,7 @@ int suspend_enter(suspend_state_t state) static void suspend_finish(suspend_state_t state) { device_resume(); + resume_console(); thaw_processes(); enable_nonboot_cpus(); if (pm_ops && pm_ops->finish) diff --git a/kernel/printk.c b/kernel/printk.c index c056f332443..19a95561929 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -67,6 +67,7 @@ EXPORT_SYMBOL(oops_in_progress); * driver system. */ static DECLARE_MUTEX(console_sem); +static DECLARE_MUTEX(secondary_console_sem); struct console *console_drivers; /* * This is used for debugging the mess that is the VT code by @@ -76,7 +77,7 @@ struct console *console_drivers; * path in the console code where we end up in places I want * locked without the console sempahore held */ -static int console_locked; +static int console_locked, console_suspended; /* * logbuf_lock protects log_buf, log_start, log_end, con_start and logged_chars @@ -698,6 +699,23 @@ int __init add_preferred_console(char *name, int idx, char *options) } /** + * suspend_console - suspend the console subsystem + * + * This disables printk() while we go into suspend states + */ +void suspend_console(void) +{ + acquire_console_sem(); + console_suspended = 1; +} + +void resume_console(void) +{ + console_suspended = 0; + release_console_sem(); +} + +/** * acquire_console_sem - lock the console system for exclusive use. * * Acquires a semaphore which guarantees that the caller has @@ -708,6 +726,10 @@ int __init add_preferred_console(char *name, int idx, char *options) void acquire_console_sem(void) { BUG_ON(in_interrupt()); + if (console_suspended) { + down(&secondary_console_sem); + return; + } down(&console_sem); console_locked = 1; console_may_schedule = 1; @@ -750,6 +772,10 @@ void release_console_sem(void) unsigned long _con_start, _log_end; unsigned long wake_klogd = 0; + if (console_suspended) { + up(&secondary_console_sem); + return; + } for ( ; ; ) { spin_lock_irqsave(&logbuf_lock, flags); wake_klogd |= log_start - log_end; diff --git a/kernel/sched.c b/kernel/sched.c index 4c64f85698a..c13f1bd2df7 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -665,55 +665,13 @@ static int effective_prio(task_t *p) } /* - * We place interactive tasks back into the active array, if possible. - * - * To guarantee that this does not starve expired tasks we ignore the - * interactivity of a task if the first expired task had to wait more - * than a 'reasonable' amount of time. This deadline timeout is - * load-dependent, as the frequency of array switched decreases with - * increasing number of running tasks. We also ignore the interactivity - * if a better static_prio task has expired, and switch periodically - * regardless, to ensure that highly interactive tasks do not starve - * the less fortunate for unreasonably long periods. - */ -static inline int expired_starving(runqueue_t *rq) -{ - int limit; - - /* - * Arrays were recently switched, all is well - */ - if (!rq->expired_timestamp) - return 0; - - limit = STARVATION_LIMIT * rq->nr_running; - - /* - * It's time to switch arrays - */ - if (jiffies - rq->expired_timestamp >= limit) - return 1; - - /* - * There's a better selection in the expired array - */ - if (rq->curr->static_prio > rq->best_expired_prio) - return 1; - - /* - * All is well - */ - return 0; -} - -/* * __activate_task - move a task to the runqueue. */ static void __activate_task(task_t *p, runqueue_t *rq) { prio_array_t *target = rq->active; - if (unlikely(batch_task(p) || (expired_starving(rq) && !rt_task(p)))) + if (batch_task(p)) target = rq->expired; enqueue_task(p, target); rq->nr_running++; @@ -2532,6 +2490,22 @@ unsigned long long current_sched_time(const task_t *tsk) } /* + * We place interactive tasks back into the active array, if possible. + * + * To guarantee that this does not starve expired tasks we ignore the + * interactivity of a task if the first expired task had to wait more + * than a 'reasonable' amount of time. This deadline timeout is + * load-dependent, as the frequency of array switched decreases with + * increasing number of running tasks. We also ignore the interactivity + * if a better static_prio task has expired: + */ +#define EXPIRED_STARVING(rq) \ + ((STARVATION_LIMIT && ((rq)->expired_timestamp && \ + (jiffies - (rq)->expired_timestamp >= \ + STARVATION_LIMIT * ((rq)->nr_running) + 1))) || \ + ((rq)->curr->static_prio > (rq)->best_expired_prio)) + +/* * Account user cpu time to a process. * @p: the process that the cpu time gets accounted to * @hardirq_offset: the offset to subtract from hardirq_count() @@ -2666,7 +2640,7 @@ void scheduler_tick(void) if (!rq->expired_timestamp) rq->expired_timestamp = jiffies; - if (!TASK_INTERACTIVE(p) || expired_starving(rq)) { + if (!TASK_INTERACTIVE(p) || EXPIRED_STARVING(rq)) { enqueue_task(p, rq->expired); if (p->static_prio < rq->best_expired_prio) rq->best_expired_prio = p->static_prio; diff --git a/kernel/timer.c b/kernel/timer.c index 67eaf0f5409..9e49deed468 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -541,6 +541,22 @@ found: } spin_unlock(&base->lock); + /* + * It can happen that other CPUs service timer IRQs and increment + * jiffies, but we have not yet got a local timer tick to process + * the timer wheels. In that case, the expiry time can be before + * jiffies, but since the high-resolution timer here is relative to + * jiffies, the default expression when high-resolution timers are + * not active, + * + * time_before(MAX_JIFFY_OFFSET + jiffies, expires) + * + * would falsely evaluate to true. If that is the case, just + * return jiffies so that we can immediately fire the local timer + */ + if (time_before(expires, jiffies)) + return jiffies; + if (time_before(hr_expires, expires)) return hr_expires; |