diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/cpuset.c | 35 | ||||
| -rw-r--r-- | kernel/fork.c | 9 | ||||
| -rw-r--r-- | kernel/hrtimer.c | 13 | ||||
| -rw-r--r-- | kernel/power/snapshot.c | 4 | ||||
| -rw-r--r-- | kernel/power/swsusp.c | 4 | ||||
| -rw-r--r-- | kernel/ptrace.c | 28 | ||||
| -rw-r--r-- | kernel/sched.c | 23 | ||||
| -rw-r--r-- | kernel/sysctl.c | 2 | ||||
| -rw-r--r-- | kernel/timer.c | 39 |
9 files changed, 115 insertions, 42 deletions
diff --git a/kernel/cpuset.c b/kernel/cpuset.c index ba42b0a..12815d3 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -1977,6 +1977,39 @@ void cpuset_fork(struct task_struct *child) * We don't need to task_lock() this reference to tsk->cpuset, * because tsk is already marked PF_EXITING, so attach_task() won't * mess with it, or task is a failed fork, never visible to attach_task. + * + * Hack: + * + * Set the exiting tasks cpuset to the root cpuset (top_cpuset). + * + * Don't leave a task unable to allocate memory, as that is an + * accident waiting to happen should someone add a callout in + * do_exit() after the cpuset_exit() call that might allocate. + * If a task tries to allocate memory with an invalid cpuset, + * it will oops in cpuset_update_task_memory_state(). + * + * We call cpuset_exit() while the task is still competent to + * handle notify_on_release(), then leave the task attached to + * the root cpuset (top_cpuset) for the remainder of its exit. + * + * To do this properly, we would increment the reference count on + * top_cpuset, and near the very end of the kernel/exit.c do_exit() + * code we would add a second cpuset function call, to drop that + * reference. This would just create an unnecessary hot spot on + * the top_cpuset reference count, to no avail. + * + * Normally, holding a reference to a cpuset without bumping its + * count is unsafe. The cpuset could go away, or someone could + * attach us to a different cpuset, decrementing the count on + * the first cpuset that we never incremented. But in this case, + * top_cpuset isn't going away, and either task has PF_EXITING set, + * which wards off any attach_task() attempts, or task is a failed + * fork, never visible to attach_task. + * + * Another way to do this would be to set the cpuset pointer + * to NULL here, and check in cpuset_update_task_memory_state() + * for a NULL pointer. This hack avoids that NULL check, for no + * cost (other than this way too long comment ;). **/ void cpuset_exit(struct task_struct *tsk) @@ -1984,7 +2017,7 @@ void cpuset_exit(struct task_struct *tsk) struct cpuset *cs; cs = tsk->cpuset; - tsk->cpuset = NULL; + tsk->cpuset = &top_cpuset; /* Hack - see comment above */ if (notify_on_release(cs)) { char *pathbuf = NULL; diff --git a/kernel/fork.c b/kernel/fork.c index 8e88b37..fbea12d 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1123,8 +1123,8 @@ static task_t *copy_process(unsigned long clone_flags, p->real_parent = current; p->parent = p->real_parent; + spin_lock(¤t->sighand->siglock); if (clone_flags & CLONE_THREAD) { - spin_lock(¤t->sighand->siglock); /* * Important: if an exit-all has been started then * do not create this new thread - the whole thread @@ -1162,8 +1162,6 @@ static task_t *copy_process(unsigned long clone_flags, */ p->it_prof_expires = jiffies_to_cputime(1); } - - spin_unlock(¤t->sighand->siglock); } /* @@ -1175,8 +1173,6 @@ static task_t *copy_process(unsigned long clone_flags, if (unlikely(p->ptrace & PT_PTRACED)) __ptrace_link(p, current->parent); - attach_pid(p, PIDTYPE_PID, p->pid); - attach_pid(p, PIDTYPE_TGID, p->tgid); if (thread_group_leader(p)) { p->signal->tty = current->signal->tty; p->signal->pgrp = process_group(current); @@ -1186,9 +1182,12 @@ static task_t *copy_process(unsigned long clone_flags, if (p->pid) __get_cpu_var(process_counts)++; } + attach_pid(p, PIDTYPE_TGID, p->tgid); + attach_pid(p, PIDTYPE_PID, p->pid); nr_threads++; total_forks++; + spin_unlock(¤t->sighand->siglock); write_unlock_irq(&tasklist_lock); proc_fork_connector(p); return p; diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index 2b6e175..5ae51f1 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -418,8 +418,19 @@ hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode) /* Switch the timer base, if necessary: */ new_base = switch_hrtimer_base(timer, base); - if (mode == HRTIMER_REL) + if (mode == HRTIMER_REL) { tim = ktime_add(tim, new_base->get_time()); + /* + * CONFIG_TIME_LOW_RES is a temporary way for architectures + * to signal that they simply return xtime in + * do_gettimeoffset(). In this case we want to round up by + * resolution when starting a relative timer, to avoid short + * timeouts. This will go away with the GTOD framework. + */ +#ifdef CONFIG_TIME_LOW_RES + tim = ktime_add(tim, base->resolution); +#endif + } timer->expires = tim; enqueue_hrtimer(timer, new_base); diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index 41f6636..8d5a598 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -91,10 +91,8 @@ static int save_highmem_zone(struct zone *zone) * corrected eventually when the cases giving rise to this * are better understood. */ - if (PageReserved(page)) { - printk("highmem reserved page?!\n"); + if (PageReserved(page)) continue; - } BUG_ON(PageNosave(page)); if (PageNosaveFree(page)) continue; diff --git a/kernel/power/swsusp.c b/kernel/power/swsusp.c index 4e90905..2d9d08f 100644 --- a/kernel/power/swsusp.c +++ b/kernel/power/swsusp.c @@ -153,13 +153,11 @@ static int swsusp_swap_check(void) /* This is called before saving image */ { int i; - if (!swsusp_resume_device) - return -ENODEV; spin_lock(&swap_lock); for (i = 0; i < MAX_SWAPFILES; i++) { if (!(swap_info[i].flags & SWP_WRITEOK)) continue; - if (is_resume_device(swap_info + i)) { + if (!swsusp_resume_device || is_resume_device(swap_info + i)) { spin_unlock(&swap_lock); root_swap = i; return 0; diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 5f33cdb..d95a72c 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -72,8 +72,8 @@ void ptrace_untrace(task_t *child) */ void __ptrace_unlink(task_t *child) { - if (!child->ptrace) - BUG(); + BUG_ON(!child->ptrace); + child->ptrace = 0; if (!list_empty(&child->ptrace_list)) { list_del_init(&child->ptrace_list); @@ -184,22 +184,27 @@ bad: return retval; } +void __ptrace_detach(struct task_struct *child, unsigned int data) +{ + child->exit_code = data; + /* .. re-parent .. */ + __ptrace_unlink(child); + /* .. and wake it up. */ + if (child->exit_state != EXIT_ZOMBIE) + wake_up_process(child); +} + int ptrace_detach(struct task_struct *child, unsigned int data) { if (!valid_signal(data)) - return -EIO; + return -EIO; /* Architecture-specific hardware disable .. */ ptrace_disable(child); - /* .. re-parent .. */ - child->exit_code = data; - write_lock_irq(&tasklist_lock); - __ptrace_unlink(child); - /* .. and wake it up. */ - if (child->exit_state != EXIT_ZOMBIE) - wake_up_process(child); + if (child->ptrace) + __ptrace_detach(child, data); write_unlock_irq(&tasklist_lock); return 0; @@ -242,8 +247,7 @@ int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, in if (write) { copy_to_user_page(vma, page, addr, maddr + offset, buf, bytes); - if (!PageCompound(page)) - set_page_dirty_lock(page); + set_page_dirty_lock(page); } else { copy_from_user_page(vma, page, addr, buf, maddr + offset, bytes); diff --git a/kernel/sched.c b/kernel/sched.c index 87d93be..12d291b 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -1204,9 +1204,6 @@ static int try_to_wake_up(task_t *p, unsigned int state, int sync) } } - if (p->last_waker_cpu != this_cpu) - goto out_set_cpu; - if (unlikely(!cpu_isset(this_cpu, p->cpus_allowed))) goto out_set_cpu; @@ -1277,8 +1274,6 @@ out_set_cpu: cpu = task_cpu(p); } - p->last_waker_cpu = this_cpu; - out_activate: #endif /* CONFIG_SMP */ if (old_state == TASK_UNINTERRUPTIBLE) { @@ -1360,12 +1355,9 @@ void fastcall sched_fork(task_t *p, int clone_flags) #ifdef CONFIG_SCHEDSTATS memset(&p->sched_info, 0, sizeof(p->sched_info)); #endif -#if defined(CONFIG_SMP) - p->last_waker_cpu = cpu; -#if defined(__ARCH_WANT_UNLOCKED_CTXSW) +#if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW) p->oncpu = 0; #endif -#endif #ifdef CONFIG_PREEMPT /* Want to start with kernel preemption disabled. */ task_thread_info(p)->preempt_count = 1; @@ -5066,7 +5058,18 @@ static void init_sched_build_groups(struct sched_group groups[], cpumask_t span, #define MAX_DOMAIN_DISTANCE 32 static unsigned long long migration_cost[MAX_DOMAIN_DISTANCE] = - { [ 0 ... MAX_DOMAIN_DISTANCE-1 ] = -1LL }; + { [ 0 ... MAX_DOMAIN_DISTANCE-1 ] = +/* + * Architectures may override the migration cost and thus avoid + * boot-time calibration. Unit is nanoseconds. Mostly useful for + * virtualized hardware: + */ +#ifdef CONFIG_DEFAULT_MIGRATION_COST + CONFIG_DEFAULT_MIGRATION_COST +#else + -1LL +#endif +}; /* * Allow override of migration cost - in units of microseconds. diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 71dd6f6..7654d55 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -126,8 +126,6 @@ extern int sysctl_hz_timer; extern int acct_parm[]; #endif -int randomize_va_space = 1; - static int parse_table(int __user *, int, void __user *, size_t __user *, void __user *, size_t, ctl_table *, void **); static int proc_doutsstring(ctl_table *table, int write, struct file *filp, diff --git a/kernel/timer.c b/kernel/timer.c index b9dad39..fe3a9a9 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -717,12 +717,16 @@ static void second_overflow(void) #endif } -/* in the NTP reference this is called "hardclock()" */ -static void update_wall_time_one_tick(void) +/* + * Returns how many microseconds we need to add to xtime this tick + * in doing an adjustment requested with adjtime. + */ +static long adjtime_adjustment(void) { - long time_adjust_step, delta_nsec; + long time_adjust_step; - if ((time_adjust_step = time_adjust) != 0 ) { + time_adjust_step = time_adjust; + if (time_adjust_step) { /* * We are doing an adjtime thing. Prepare time_adjust_step to * be within bounds. Note that a positive time_adjust means we @@ -733,10 +737,19 @@ static void update_wall_time_one_tick(void) */ time_adjust_step = min(time_adjust_step, (long)tickadj); time_adjust_step = max(time_adjust_step, (long)-tickadj); + } + return time_adjust_step; +} +/* in the NTP reference this is called "hardclock()" */ +static void update_wall_time_one_tick(void) +{ + long time_adjust_step, delta_nsec; + + time_adjust_step = adjtime_adjustment(); + if (time_adjust_step) /* Reduce by this step the amount of time left */ time_adjust -= time_adjust_step; - } delta_nsec = tick_nsec + time_adjust_step * 1000; /* * Advance the phase, once it gets to one microsecond, then @@ -759,6 +772,22 @@ static void update_wall_time_one_tick(void) } /* + * Return how long ticks are at the moment, that is, how much time + * update_wall_time_one_tick will add to xtime next time we call it + * (assuming no calls to do_adjtimex in the meantime). + * The return value is in fixed-point nanoseconds with SHIFT_SCALE-10 + * bits to the right of the binary point. + * This function has no side-effects. + */ +u64 current_tick_length(void) +{ + long delta_nsec; + + delta_nsec = tick_nsec + adjtime_adjustment() * 1000; + return ((u64) delta_nsec << (SHIFT_SCALE - 10)) + time_adj; +} + +/* * Using a loop looks inefficient, but "ticks" is * usually just one (we shouldn't be losing ticks, * we're doing this this way mainly for interrupt |