diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/Makefile | 1 | ||||
| -rw-r--r-- | kernel/acct.c | 43 | ||||
| -rw-r--r-- | kernel/compat.c | 9 | ||||
| -rw-r--r-- | kernel/cpuset.c | 100 | ||||
| -rw-r--r-- | kernel/sched.c | 232 | ||||
| -rw-r--r-- | kernel/signal.c | 3 | ||||
| -rw-r--r-- | kernel/spinlock.c | 15 | ||||
| -rw-r--r-- | kernel/timer.c | 32 |
8 files changed, 290 insertions, 145 deletions
diff --git a/kernel/Makefile b/kernel/Makefile index 8d57a2f1226..ff4dc02ce17 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -12,6 +12,7 @@ obj-y = sched.o fork.o exec_domain.o panic.o printk.o profile.o \ obj-$(CONFIG_FUTEX) += futex.o obj-$(CONFIG_GENERIC_ISA_DMA) += dma.o obj-$(CONFIG_SMP) += cpu.o spinlock.o +obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock.o obj-$(CONFIG_UID16) += uid16.o obj-$(CONFIG_MODULES) += module.o obj-$(CONFIG_KALLSYMS) += kallsyms.o diff --git a/kernel/acct.c b/kernel/acct.c index f70e6027cca..b756f527497 100644 --- a/kernel/acct.c +++ b/kernel/acct.c @@ -165,7 +165,7 @@ out: } /* - * Close the old accouting file (if currently open) and then replace + * Close the old accounting file (if currently open) and then replace * it with file (if non-NULL). * * NOTE: acct_globals.lock MUST be held on entry and exit. @@ -199,11 +199,16 @@ static void acct_file_reopen(struct file *file) } } -/* - * sys_acct() is the only system call needed to implement process - * accounting. It takes the name of the file where accounting records - * should be written. If the filename is NULL, accounting will be - * shutdown. +/** + * sys_acct - enable/disable process accounting + * @name: file name for accounting records or NULL to shutdown accounting + * + * Returns 0 for success or negative errno values for failure. + * + * sys_acct() is the only system call needed to implement process + * accounting. It takes the name of the file where accounting records + * should be written. If the filename is NULL, accounting will be + * shutdown. */ asmlinkage long sys_acct(const char __user *name) { @@ -250,9 +255,12 @@ asmlinkage long sys_acct(const char __user *name) return (0); } -/* - * If the accouting is turned on for a file in the filesystem pointed - * to by sb, turn accouting off. +/** + * acct_auto_close - turn off a filesystem's accounting if it is on + * @sb: super block for the filesystem + * + * If the accounting is turned on for a file in the filesystem pointed + * to by sb, turn accounting off. */ void acct_auto_close(struct super_block *sb) { @@ -503,8 +511,11 @@ static void do_acct_process(long exitcode, struct file *file) set_fs(fs); } -/* +/** * acct_process - now just a wrapper around do_acct_process + * @exitcode: task exit code + * + * handles process accounting for an exiting task */ void acct_process(long exitcode) { @@ -530,9 +541,9 @@ void acct_process(long exitcode) } -/* - * acct_update_integrals - * - update mm integral fields in task_struct +/** + * acct_update_integrals - update mm integral fields in task_struct + * @tsk: task_struct for accounting */ void acct_update_integrals(struct task_struct *tsk) { @@ -547,9 +558,9 @@ void acct_update_integrals(struct task_struct *tsk) } } -/* - * acct_clear_integrals - * - clear the mm integral fields in task_struct +/** + * acct_clear_integrals - clear the mm integral fields in task_struct + * @tsk: task_struct whose accounting fields are cleared */ void acct_clear_integrals(struct task_struct *tsk) { diff --git a/kernel/compat.c b/kernel/compat.c index ddfcaaa8662..102296e21ea 100644 --- a/kernel/compat.c +++ b/kernel/compat.c @@ -48,8 +48,7 @@ static long compat_nanosleep_restart(struct restart_block *restart) if (!time_after(expire, now)) return 0; - current->state = TASK_INTERRUPTIBLE; - expire = schedule_timeout(expire - now); + expire = schedule_timeout_interruptible(expire - now); if (expire == 0) return 0; @@ -82,8 +81,7 @@ asmlinkage long compat_sys_nanosleep(struct compat_timespec __user *rqtp, return -EINVAL; expire = timespec_to_jiffies(&t) + (t.tv_sec || t.tv_nsec); - current->state = TASK_INTERRUPTIBLE; - expire = schedule_timeout(expire); + expire = schedule_timeout_interruptible(expire); if (expire == 0) return 0; @@ -795,8 +793,7 @@ compat_sys_rt_sigtimedwait (compat_sigset_t __user *uthese, recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); - current->state = TASK_INTERRUPTIBLE; - timeout = schedule_timeout(timeout); + timeout = schedule_timeout_interruptible(timeout); spin_lock_irq(¤t->sighand->siglock); sig = dequeue_signal(current, &s, &info); diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 712d0202997..407b5f0a8c8 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -182,6 +182,37 @@ static struct super_block *cpuset_sb = NULL; static DECLARE_MUTEX(cpuset_sem); /* + * The global cpuset semaphore cpuset_sem can be needed by the + * memory allocator to update a tasks mems_allowed (see the calls + * to cpuset_update_current_mems_allowed()) or to walk up the + * cpuset hierarchy to find a mem_exclusive cpuset see the calls + * to cpuset_excl_nodes_overlap()). + * + * But if the memory allocation is being done by cpuset.c code, it + * usually already holds cpuset_sem. Double tripping on a kernel + * semaphore deadlocks the current task, and any other task that + * subsequently tries to obtain the lock. + * + * Run all up's and down's on cpuset_sem through the following + * wrappers, which will detect this nested locking, and avoid + * deadlocking. + */ + +static inline void cpuset_down(struct semaphore *psem) +{ + if (current->cpuset_sem_nest_depth == 0) + down(psem); + current->cpuset_sem_nest_depth++; +} + +static inline void cpuset_up(struct semaphore *psem) +{ + current->cpuset_sem_nest_depth--; + if (current->cpuset_sem_nest_depth == 0) + up(psem); +} + +/* * A couple of forward declarations required, due to cyclic reference loop: * cpuset_mkdir -> cpuset_create -> cpuset_populate_dir -> cpuset_add_file * -> cpuset_create_file -> cpuset_dir_inode_operations -> cpuset_mkdir. @@ -522,19 +553,10 @@ static void guarantee_online_mems(const struct cpuset *cs, nodemask_t *pmask) * Refresh current tasks mems_allowed and mems_generation from * current tasks cpuset. Call with cpuset_sem held. * - * Be sure to call refresh_mems() on any cpuset operation which - * (1) holds cpuset_sem, and (2) might possibly alloc memory. - * Call after obtaining cpuset_sem lock, before any possible - * allocation. Otherwise one risks trying to allocate memory - * while the task cpuset_mems_generation is not the same as - * the mems_generation in its cpuset, which would deadlock on - * cpuset_sem in cpuset_update_current_mems_allowed(). - * - * Since we hold cpuset_sem, once refresh_mems() is called, the - * test (current->cpuset_mems_generation != cs->mems_generation) - * in cpuset_update_current_mems_allowed() will remain false, - * until we drop cpuset_sem. Anyone else who would change our - * cpusets mems_generation needs to lock cpuset_sem first. + * This routine is needed to update the per-task mems_allowed + * data, within the tasks context, when it is trying to allocate + * memory (in various mm/mempolicy.c routines) and notices + * that some other task has been modifying its cpuset. */ static void refresh_mems(void) @@ -840,7 +862,7 @@ static ssize_t cpuset_common_file_write(struct file *file, const char __user *us } buffer[nbytes] = 0; /* nul-terminate */ - down(&cpuset_sem); + cpuset_down(&cpuset_sem); if (is_removed(cs)) { retval = -ENODEV; @@ -874,7 +896,7 @@ static ssize_t cpuset_common_file_write(struct file *file, const char __user *us if (retval == 0) retval = nbytes; out2: - up(&cpuset_sem); + cpuset_up(&cpuset_sem); cpuset_release_agent(pathbuf); out1: kfree(buffer); @@ -914,9 +936,9 @@ static int cpuset_sprintf_cpulist(char *page, struct cpuset *cs) { cpumask_t mask; - down(&cpuset_sem); + cpuset_down(&cpuset_sem); mask = cs->cpus_allowed; - up(&cpuset_sem); + cpuset_up(&cpuset_sem); return cpulist_scnprintf(page, PAGE_SIZE, mask); } @@ -925,9 +947,9 @@ static int cpuset_sprintf_memlist(char *page, struct cpuset *cs) { nodemask_t mask; - down(&cpuset_sem); + cpuset_down(&cpuset_sem); mask = cs->mems_allowed; - up(&cpuset_sem); + cpuset_up(&cpuset_sem); return nodelist_scnprintf(page, PAGE_SIZE, mask); } @@ -1334,8 +1356,7 @@ static long cpuset_create(struct cpuset *parent, const char *name, int mode) if (!cs) return -ENOMEM; - down(&cpuset_sem); - refresh_mems(); + cpuset_down(&cpuset_sem); cs->flags = 0; if (notify_on_release(parent)) set_bit(CS_NOTIFY_ON_RELEASE, &cs->flags); @@ -1360,14 +1381,14 @@ static long cpuset_create(struct cpuset *parent, const char *name, int mode) * will down() this new directory's i_sem and if we race with * another mkdir, we might deadlock. */ - up(&cpuset_sem); + cpuset_up(&cpuset_sem); err = cpuset_populate_dir(cs->dentry); /* If err < 0, we have a half-filled directory - oh well ;) */ return 0; err: list_del(&cs->sibling); - up(&cpuset_sem); + cpuset_up(&cpuset_sem); kfree(cs); return err; } @@ -1389,14 +1410,13 @@ static int cpuset_rmdir(struct inode *unused_dir, struct dentry *dentry) /* the vfs holds both inode->i_sem already */ - down(&cpuset_sem); - refresh_mems(); + cpuset_down(&cpuset_sem); if (atomic_read(&cs->count) > 0) { - up(&cpuset_sem); + cpuset_up(&cpuset_sem); return -EBUSY; } if (!list_empty(&cs->children)) { - up(&cpuset_sem); + cpuset_up(&cpuset_sem); return -EBUSY; } parent = cs->parent; @@ -1412,7 +1432,7 @@ static int cpuset_rmdir(struct inode *unused_dir, struct dentry *dentry) spin_unlock(&d->d_lock); cpuset_d_remove_dir(d); dput(d); - up(&cpuset_sem); + cpuset_up(&cpuset_sem); cpuset_release_agent(pathbuf); return 0; } @@ -1515,10 +1535,10 @@ void cpuset_exit(struct task_struct *tsk) if (notify_on_release(cs)) { char *pathbuf = NULL; - down(&cpuset_sem); + cpuset_down(&cpuset_sem); if (atomic_dec_and_test(&cs->count)) check_for_release(cs, &pathbuf); - up(&cpuset_sem); + cpuset_up(&cpuset_sem); cpuset_release_agent(pathbuf); } else { atomic_dec(&cs->count); @@ -1539,11 +1559,11 @@ cpumask_t cpuset_cpus_allowed(const struct task_struct *tsk) { cpumask_t mask; - down(&cpuset_sem); + cpuset_down(&cpuset_sem); task_lock((struct task_struct *)tsk); guarantee_online_cpus(tsk->cpuset, &mask); task_unlock((struct task_struct *)tsk); - up(&cpuset_sem); + cpuset_up(&cpuset_sem); return mask; } @@ -1568,9 +1588,9 @@ void cpuset_update_current_mems_allowed(void) if (!cs) return; /* task is exiting */ if (current->cpuset_mems_generation != cs->mems_generation) { - down(&cpuset_sem); + cpuset_down(&cpuset_sem); refresh_mems(); - up(&cpuset_sem); + cpuset_up(&cpuset_sem); } } @@ -1669,14 +1689,14 @@ int cpuset_zone_allowed(struct zone *z, unsigned int __nocast gfp_mask) return 0; /* Not hardwall and node outside mems_allowed: scan up cpusets */ - down(&cpuset_sem); + cpuset_down(&cpuset_sem); cs = current->cpuset; if (!cs) goto done; /* current task exiting */ cs = nearest_exclusive_ancestor(cs); allowed = node_isset(node, cs->mems_allowed); done: - up(&cpuset_sem); + cpuset_up(&cpuset_sem); return allowed; } @@ -1697,7 +1717,7 @@ int cpuset_excl_nodes_overlap(const struct task_struct *p) const struct cpuset *cs1, *cs2; /* my and p's cpuset ancestors */ int overlap = 0; /* do cpusets overlap? */ - down(&cpuset_sem); + cpuset_down(&cpuset_sem); cs1 = current->cpuset; if (!cs1) goto done; /* current task exiting */ @@ -1708,7 +1728,7 @@ int cpuset_excl_nodes_overlap(const struct task_struct *p) cs2 = nearest_exclusive_ancestor(cs2); overlap = nodes_intersects(cs1->mems_allowed, cs2->mems_allowed); done: - up(&cpuset_sem); + cpuset_up(&cpuset_sem); return overlap; } @@ -1731,7 +1751,7 @@ static int proc_cpuset_show(struct seq_file *m, void *v) return -ENOMEM; tsk = m->private; - down(&cpuset_sem); + cpuset_down(&cpuset_sem); task_lock(tsk); cs = tsk->cpuset; task_unlock(tsk); @@ -1746,7 +1766,7 @@ static int proc_cpuset_show(struct seq_file *m, void *v) seq_puts(m, buf); seq_putc(m, '\n'); out: - up(&cpuset_sem); + cpuset_up(&cpuset_sem); kfree(buf); return retval; } diff --git a/kernel/sched.c b/kernel/sched.c index 2632b812cf2..dbd4490afec 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -875,7 +875,7 @@ static int migrate_task(task_t *p, int dest_cpu, migration_req_t *req) * smp_call_function() if an IPI is sent by the same process we are * waiting to become inactive. */ -void wait_task_inactive(task_t * p) +void wait_task_inactive(task_t *p) { unsigned long flags; runqueue_t *rq; @@ -966,8 +966,11 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p, int this_cpu) int local_group; int i; + /* Skip over this group if it has no CPUs allowed */ + if (!cpus_intersects(group->cpumask, p->cpus_allowed)) + goto nextgroup; + local_group = cpu_isset(this_cpu, group->cpumask); - /* XXX: put a cpus allowed check */ /* Tally up the load of all CPUs in the group */ avg_load = 0; @@ -992,6 +995,7 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p, int this_cpu) min_load = avg_load; idlest = group; } +nextgroup: group = group->next; } while (group != sd->groups); @@ -1003,13 +1007,18 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p, int this_cpu) /* * find_idlest_queue - find the idlest runqueue among the cpus in group. */ -static int find_idlest_cpu(struct sched_group *group, int this_cpu) +static int +find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu) { + cpumask_t tmp; unsigned long load, min_load = ULONG_MAX; int idlest = -1; int i; - for_each_cpu_mask(i, group->cpumask) { + /* Traverse only the allowed CPUs */ + cpus_and(tmp, group->cpumask, p->cpus_allowed); + + for_each_cpu_mask(i, tmp) { load = source_load(i, 0); if (load < min_load || (load == min_load && i == this_cpu)) { @@ -1052,7 +1061,7 @@ static int sched_balance_self(int cpu, int flag) if (!group) goto nextlevel; - new_cpu = find_idlest_cpu(group, cpu); + new_cpu = find_idlest_cpu(group, t, cpu); if (new_cpu == -1 || new_cpu == cpu) goto nextlevel; @@ -1127,7 +1136,7 @@ static inline int wake_idle(int cpu, task_t *p) * * returns failure only if the task is already active. */ -static int try_to_wake_up(task_t * p, unsigned int state, int sync) +static int try_to_wake_up(task_t *p, unsigned int state, int sync) { int cpu, this_cpu, success = 0; unsigned long flags; @@ -1252,6 +1261,16 @@ out_activate: } /* + * Tasks that have marked their sleep as noninteractive get + * woken up without updating their sleep average. (i.e. their + * sleep is handled in a priority-neutral manner, no priority + * boost and no penalty.) + */ + if (old_state & TASK_NONINTERACTIVE) + __activate_task(p, rq); + else + activate_task(p, rq, cpu == this_cpu); + /* * Sync wakeups (i.e. those types of wakeups where the waker * has indicated that it will leave the CPU in short order) * don't trigger a preemption, if the woken up task will run on @@ -1259,7 +1278,6 @@ out_activate: * the waker guarantees that the freshly woken up task is going * to be considered on this CPU.) */ - activate_task(p, rq, cpu == this_cpu); if (!sync || cpu != this_cpu) { if (TASK_PREEMPTS_CURR(p, rq)) resched_task(rq->curr); @@ -1274,7 +1292,7 @@ out: return success; } -int fastcall wake_up_process(task_t * p) +int fastcall wake_up_process(task_t *p) { return try_to_wake_up(p, TASK_STOPPED | TASK_TRACED | TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE, 0); @@ -1353,7 +1371,7 @@ void fastcall sched_fork(task_t *p, int clone_flags) * that must be done for every newly created context, then puts the task * on the runqueue and wakes it. */ -void fastcall wake_up_new_task(task_t * p, unsigned long clone_flags) +void fastcall wake_up_new_task(task_t *p, unsigned long clone_flags) { unsigned long flags; int this_cpu, cpu; @@ -1436,7 +1454,7 @@ void fastcall wake_up_new_task(task_t * p, unsigned long clone_flags) * artificially, because any timeslice recovered here * was given away by the parent in the first place.) */ -void fastcall sched_exit(task_t * p) +void fastcall sched_exit(task_t *p) { unsigned long flags; runqueue_t *rq; @@ -1511,6 +1529,10 @@ static inline void finish_task_switch(runqueue_t *rq, task_t *prev) * Manfred Spraul <manfred@colorfullife.com> */ prev_task_flags = prev->flags; +#ifdef CONFIG_DEBUG_SPINLOCK + /* this is a valid case when another task releases the spinlock */ + rq->lock.owner = current; +#endif finish_arch_switch(prev); finish_lock_switch(rq, prev); if (mm) @@ -1753,7 +1775,8 @@ void pull_task(runqueue_t *src_rq, prio_array_t *src_array, task_t *p, */ static inline int can_migrate_task(task_t *p, runqueue_t *rq, int this_cpu, - struct sched_domain *sd, enum idle_type idle, int *all_pinned) + struct sched_domain *sd, enum idle_type idle, + int *all_pinned) { /* * We do not migrate tasks that are: @@ -1883,10 +1906,11 @@ out: */ static struct sched_group * find_busiest_group(struct sched_domain *sd, int this_cpu, - unsigned long *imbalance, enum idle_type idle) + unsigned long *imbalance, enum idle_type idle, int *sd_idle) { struct sched_group *busiest = NULL, *this = NULL, *group = sd->groups; unsigned long max_load, avg_load, total_load, this_load, total_pwr; + unsigned long max_pull; int load_idx; max_load = this_load = total_load = total_pwr = 0; @@ -1908,6 +1932,9 @@ find_busiest_group(struct sched_domain *sd, int this_cpu, avg_load = 0; for_each_cpu_mask(i, group->cpumask) { + if (*sd_idle && !idle_cpu(i)) + *sd_idle = 0; + /* Bias balancing toward cpus of our domain */ if (local_group) load = target_load(i, load_idx); @@ -1933,7 +1960,7 @@ find_busiest_group(struct sched_domain *sd, int this_cpu, group = group->next; } while (group != sd->groups); - if (!busiest || this_load >= max_load) + if (!busiest || this_load >= max_load || max_load <= SCHED_LOAD_SCALE) goto out_balanced; avg_load = (SCHED_LOAD_SCALE * total_load) / total_pwr; @@ -1953,8 +1980,12 @@ find_busiest_group(struct sched_domain *sd, int this_cpu, * by pulling tasks to us. Be careful of negative numbers as they'll * appear as very large values with unsigned longs. */ + + /* Don't want to pull so many tasks that a group would go idle */ + max_pull = min(max_load - avg_load, max_load - SCHED_LOAD_SCALE); + /* How much load to actually move to equalise the imbalance */ - *imbalance = min((max_load - avg_load) * busiest->cpu_power, + *imbalance = min(max_pull * busiest->cpu_power, (avg_load - this_load) * this->cpu_power) / SCHED_LOAD_SCALE; @@ -2051,11 +2082,14 @@ static int load_balance(int this_cpu, runqueue_t *this_rq, unsigned long imbalance; int nr_moved, all_pinned = 0; int active_balance = 0; + int sd_idle = 0; + + if (idle != NOT_IDLE && sd->flags & SD_SHARE_CPUPOWER) + sd_idle = 1; - spin_lock(&this_rq->lock); schedstat_inc(sd, lb_cnt[idle]); - group = find_busiest_group(sd, this_cpu, &imbalance, idle); + group = find_busiest_group(sd, this_cpu, &imbalance, idle, &sd_idle); if (!group) { schedstat_inc(sd, lb_nobusyg[idle]); goto out_balanced; @@ -2079,19 +2113,16 @@ static int load_balance(int this_cpu, runqueue_t *this_rq, * still unbalanced. nr_moved simply stays zero, so it is * correctly treated as an imbalance. */ - double_lock_balance(this_rq, busiest); + double_rq_lock(this_rq, busiest); nr_moved = move_tasks(this_rq, this_cpu, busiest, - imbalance, sd, idle, - &all_pinned); - spin_unlock(&busiest->lock); + imbalance, sd, idle, &all_pinned); + double_rq_unlock(this_rq, busiest); /* All tasks on this runqueue were pinned by CPU affinity */ if (unlikely(all_pinned)) goto out_balanced; } - spin_unlock(&this_rq->lock); - if (!nr_moved) { schedstat_inc(sd, lb_failed[idle]); sd->nr_balance_failed++; @@ -2099,6 +2130,16 @@ static int load_balance(int this_cpu, runqueue_t *this_rq, if (unlikely(sd->nr_balance_failed > sd->cache_nice_tries+2)) { spin_lock(&busiest->lock); + + /* don't kick the migration_thread, if the curr + * task on busiest cpu can't be moved to this_cpu + */ + if (!cpu_isset(this_cpu, busiest->curr->cpus_allowed)) { + spin_unlock(&busiest->lock); + all_pinned = 1; + goto out_one_pinned; + } + if (!busiest->active_balance) { busiest->active_balance = 1; busiest->push_cpu = this_cpu; @@ -2131,19 +2172,23 @@ static int load_balance(int this_cpu, runqueue_t *this_rq, sd->balance_interval *= 2; } + if (!nr_moved && !sd_idle && sd->flags & SD_SHARE_CPUPOWER) + return -1; return nr_moved; out_balanced: - spin_unlock(&this_rq->lock); - schedstat_inc(sd, lb_balanced[idle]); sd->nr_balance_failed = 0; + +out_one_pinned: /* tune up the balancing interval */ if ((all_pinned && sd->balance_interval < MAX_PINNED_INTERVAL) || (sd->balance_interval < sd->max_interval)) sd->balance_interval *= 2; + if (!sd_idle && sd->flags & SD_SHARE_CPUPOWER) + return -1; return 0; } @@ -2161,9 +2206,13 @@ static int load_balance_newidle(int this_cpu, runqueue_t *this_rq, runqueue_t *busiest = NULL; unsigned long imbalance; int nr_moved = 0; + int sd_idle = 0; + + if (sd->flags & SD_SHARE_CPUPOWER) + sd_idle = 1; schedstat_inc(sd, lb_cnt[NEWLY_IDLE]); - group = find_busiest_group(sd, this_cpu, &imbalance, NEWLY_IDLE); + group = find_busiest_group(sd, this_cpu, &imbalance, NEWLY_IDLE, &sd_idle); if (!group) { schedstat_inc(sd, lb_nobusyg[NEWLY_IDLE]); goto out_balanced; @@ -2177,22 +2226,30 @@ static int load_balance_newidle(int this_cpu, runqueue_t *this_rq, BUG_ON(busiest == this_rq); - /* Attempt to move tasks */ - double_lock_balance(this_rq, busiest); - schedstat_add(sd, lb_imbalance[NEWLY_IDLE], imbalance); - nr_moved = move_tasks(this_rq, this_cpu, busiest, + + nr_moved = 0; + if (busiest->nr_running > 1) { + /* Attempt to move tasks */ + double_lock_balance(this_rq, busiest); + nr_moved = move_tasks(this_rq, this_cpu, busiest, imbalance, sd, NEWLY_IDLE, NULL); - if (!nr_moved) + spin_unlock(&busiest->lock); + } + + if (!nr_moved) { schedstat_inc(sd, lb_failed[NEWLY_IDLE]); - else + if (!sd_idle && sd->flags & SD_SHARE_CPUPOWER) + return -1; + } else sd->nr_balance_failed = 0; - spin_unlock(&busiest->lock); return nr_moved; out_balanced: schedstat_inc(sd, lb_balanced[NEWLY_IDLE]); + if (!sd_idle && sd->flags & SD_SHARE_CPUPOWER) + return -1; sd->nr_balance_failed = 0; return 0; } @@ -2317,7 +2374,11 @@ static void rebalance_tick(int this_cpu, runqueue_t *this_rq, if (j - sd->last_balance >= interval) { if (load_balance(this_cpu, this_rq, sd, idle)) { - /* We've pulled tasks over so no longer idle */ + /* + * We've pulled tasks over so either we're no + * longer idle, or one of our SMT siblings is + * not idle. + */ idle = NOT_IDLE; } sd->last_balance += interval; @@ -2576,6 +2637,13 @@ out: } #ifdef CONFIG_SCHED_SMT +static inline void wakeup_busy_runqueue(runqueue_t *rq) +{ + /* If an SMT runqueue is sleeping due to priority reasons wake it up */ + if (rq->curr == rq->idle && rq->nr_running) + resched_task(rq->idle); +} + static inline void wake_sleeping_dependent(int this_cpu, runqueue_t *this_rq) { struct sched_domain *tmp, *sd = NULL; @@ -2609,12 +2677,7 @@ static inline void wake_sleeping_dependent(int this_cpu, runqueue_t *this_rq) for_each_cpu_mask(i, sibling_map) { runqueue_t *smt_rq = cpu_rq(i); - /* - * If an SMT sibling task is sleeping due to priority - * reasons wake it up now. - */ - if (smt_rq->curr == smt_rq->idle && smt_rq->nr_running) - resched_task(smt_rq->idle); + wakeup_busy_runqueue(smt_rq); } for_each_cpu_mask(i, sibling_map) @@ -2625,6 +2688,16 @@ static inline void wake_sleeping_dependent(int this_cpu, runqueue_t *this_rq) */ } +/* + * number of 'lost' timeslices this task wont be able to fully + * utilize, if another task runs on a sibling. This models the + * slowdown effect of other tasks running on siblings: + */ +static inline unsigned long smt_slice(task_t *p, struct sched_domain *sd) +{ + return p->time_slice * (100 - sd->per_cpu_gain) / 100; +} + static inline int dependent_sleeper(int this_cpu, runqueue_t *this_rq) { struct sched_domain *tmp, *sd = NULL; @@ -2668,6 +2741,10 @@ static inline int dependent_sleeper(int this_cpu, runqueue_t *this_rq) runqueue_t *smt_rq = cpu_rq(i); task_t *smt_curr = smt_rq->curr; + /* Kernel threads do not participate in dependent sleeping */ + if (!p->mm || !smt_curr->mm || rt_task(p)) + goto check_smt_task; + /* * If a user task with lower static priority than the * running task on the SMT sibling is trying to schedule, @@ -2676,21 +2753,45 @@ static inline int dependent_sleeper(int this_cpu, runqueue_t *this_rq) * task from using an unfair proportion of the * physical cpu's resources. -ck */ - if (((smt_curr->time_slice * (100 - sd->per_cpu_gain) / 100) > - task_timeslice(p) || rt_task(smt_curr)) && - p->mm && smt_curr->mm && !rt_task(p)) - ret = 1; + if (rt_task(smt_curr)) { + /* + * With real time tasks we run non-rt tasks only + * per_cpu_gain% of the time. + */ + if ((jiffies % DEF_TIMESLICE) > + (sd->per_cpu_gain * DEF_TIMESLICE / 100)) + ret = 1; + } else + if (smt_curr->static_prio < p->static_prio && + !TASK_PREEMPTS_CURR(p, smt_rq) && + smt_slice(smt_curr, sd) > task_timeslice(p)) + ret = 1; + +check_smt_task: + if ((!smt_curr->mm && smt_curr != smt_rq->idle) || + rt_task(smt_curr)) + continue; + if (!p->mm) { + wakeup_busy_runqueue(smt_rq); + continue; + } /* - * Reschedule a lower priority task on the SMT sibling, - * or wake it up if it has been put to sleep for priority - * reasons. + * Reschedule a lower priority task on the SMT sibling for + * it to be put to sleep, or wake it up if it has been put to + * sleep for priority reasons to see if it should run now. */ - if ((((p->time_slice * (100 - sd->per_cpu_gain) / 100) > - task_timeslice(smt_curr) || rt_task(p)) && - smt_curr->mm && p->mm && !rt_task(smt_curr)) || - (smt_curr == smt_rq->idle && smt_rq->nr_running)) - resched_task(smt_curr); + if (rt_task(p)) { + if ((jiffies % DEF_TIMESLICE) > + (sd->per_cpu_gain * DEF_TIMESLICE / 100)) + resched_task(smt_curr); + } else { + if (TASK_PREEMPTS_CURR(p, smt_rq) && + smt_slice(p, sd) > task_timeslice(smt_curr)) + resched_task(smt_curr); + else + wakeup_busy_runqueue(smt_rq); + } } out_unlock: for_each_cpu_mask(i, sibling_map) @@ -3016,7 +3117,8 @@ need_resched: #endif /* CONFIG_PREEMPT */ -int default_wake_function(wait_queue_t *curr, unsigned mode, int sync, void *key) +int default_wake_function(wait_queue_t *curr, unsigned mode, int sync, + void *key) { task_t *p = curr->private; return try_to_wake_up(p, mode, sync); @@ -3058,7 +3160,7 @@ static void __wake_up_common(wait_queue_head_t *q, unsigned int mode, * @key: is directly passed to the wakeup function */ void fastcall __wake_up(wait_queue_head_t *q, unsigned int mode, - int nr_exclusive, void *key) + int nr_exclusive, void *key) { unsigned long flags; @@ -3090,7 +3192,8 @@ void fastcall __wake_up_locked(wait_queue_head_t *q, unsigned int mode) * * On UP it can prevent extra preemption. */ -void fastcall __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive) +void fastcall +__wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive) { unsigned long flags; int sync = 1; @@ -3281,7 +3384,8 @@ void fastcall __sched interruptible_sleep_on(wait_queue_head_t *q) EXPORT_SYMBOL(interruptible_sleep_on); -long fastcall __sched interruptible_sleep_on_timeout(wait_queue_head_t *q, long timeout) +long fastcall __sched +interruptible_sleep_on_timeout(wait_queue_head_t *q, long timeout) { SLEEP_ON_VAR @@ -3500,7 +3604,8 @@ static void __setscheduler(struct task_struct *p, int policy, int prio) * @policy: new policy. * @param: structure containing the new RT priority. */ -int sched_setscheduler(struct task_struct *p, int policy, struct sched_param *param) +int sched_setscheduler(struct task_struct *p, int policy, + struct sched_param *param) { int retval; int oldprio, oldpolicy = -1; @@ -3520,7 +3625,7 @@ recheck: * 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL is 0. */ if (param->sched_priority < 0 || - (p->mm && param->sched_priority > MAX_USER_RT_PRIO-1) || + (p->mm && param->sched_priority > MAX_USER_RT_PRIO-1) || (!p->mm && param->sched_priority > MAX_RT_PRIO-1)) return -EINVAL; if ((policy == SCHED_NORMAL) != (param->sched_priority == 0)) @@ -3583,7 +3688,8 @@ recheck: } EXPORT_SYMBOL_GPL(sched_setscheduler); -static int do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param) +static int +do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param) { int retval; struct sched_param lparam; @@ -3850,7 +3956,7 @@ asmlinkage long sys_sched_yield(void) if (rt_task(current)) target = rq->active; - if (current->array->nr_active == 1) { + if (array->nr_active == 1) { schedstat_inc(rq, yld_act_empty); if (!rq->expired->nr_active) schedstat_inc(rq, yld_both_empty); @@ -3914,7 +4020,7 @@ EXPORT_SYMBOL(cond_resched); * operations here to prevent schedule() from being called twice (once via * spin_unlock(), once by hand). */ -int cond_resched_lock(spinlock_t * lock) +int cond_resched_lock(spinlock_t *lock) { int ret = 0; @@ -4097,7 +4203,7 @@ static inline struct task_struct *younger_sibling(struct task_struct *p) return list_entry(p->sibling.next,struct task_struct,sibling); } -static void show_task(task_t * p) +static void show_task(task_t *p) { task_t *relative; unsigned state; @@ -4123,7 +4229,7 @@ static void show_task(task_t * p) #endif #ifdef CONFIG_DEBUG_STACK_USAGE { - unsigned long * n = (unsigned long *) (p->thread_info+1); + unsigned long *n = (unsigned long *) (p->thread_info+1); while (!*n) n++; free = (unsigned long) n - (unsigned long)(p->thread_info+1); @@ -4332,7 +4438,7 @@ out: * thread migration by bumping thread off CPU then 'pushing' onto * another runqueue. */ -static int migration_thread(void * data) +static int migration_thread(void *data) { runqueue_t *rq; int cpu = (long)data; diff --git a/kernel/signal.c b/kernel/signal.c index 4980a073237..b92c3c9f8b9 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2221,8 +2221,7 @@ sys_rt_sigtimedwait(const sigset_t __user *uthese, recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); - current->state = TASK_INTERRUPTIBLE; - timeout = schedule_timeout(timeout); + timeout = schedule_timeout_interruptible(timeout); try_to_freeze(); spin_lock_irq(¤t->sighand->siglock); diff --git a/kernel/spinlock.c b/kernel/spinlock.c index 0c3f9d8bbe1..0375fcd5921 100644 --- a/kernel/spinlock.c +++ b/kernel/spinlock.c @@ -3,7 +3,10 @@ * * Author: Zwane Mwaikambo <zwane@fsmlabs.com> * - * Copyright (2004) Ingo Molnar + * Copyright (2004, 2005) Ingo Molnar + * + * This file contains the spinlock/rwlock implementations for the + * SMP and the DEBUG_SPINLOCK cases. (UP-nondebug inlines them) */ #include <linux/config.h> @@ -17,12 +20,12 @@ * Generic declaration of the raw read_trylock() function, * architectures are supposed to optimize this: */ -int __lockfunc generic_raw_read_trylock(rwlock_t *lock) +int __lockfunc generic__raw_read_trylock(raw_rwlock_t *lock) { - _raw_read_lock(lock); + __raw_read_lock(lock); return 1; } -EXPORT_SYMBOL(generic_raw_read_trylock); +EXPORT_SYMBOL(generic__raw_read_trylock); int __lockfunc _spin_trylock(spinlock_t *lock) { @@ -57,7 +60,7 @@ int __lockfunc _write_trylock(rwlock_t *lock) } EXPORT_SYMBOL(_write_trylock); -#ifndef CONFIG_PREEMPT +#if !defined(CONFIG_PREEMPT) || !defined(CONFIG_SMP) void __lockfunc _read_lock(rwlock_t *lock) { @@ -72,7 +75,7 @@ unsigned long __lockfunc _spin_lock_irqsave(spinlock_t *lock) local_irq_save(flags); preempt_disable(); - _raw_spin_lock_flags(lock, flags); + _raw_spin_lock_flags(lock, &flags); return flags; } EXPORT_SYMBOL(_spin_lock_irqsave); diff --git a/kernel/timer.c b/kernel/timer.c index 13e2b513be0..f4152fcd9f8 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -1154,6 +1154,20 @@ fastcall signed long __sched schedule_timeout(signed long timeout) EXPORT_SYMBOL(schedule_timeout); +signed long __sched schedule_timeout_interruptible(signed long timeout) +{ + set_current_state(TASK_INTERRUPTIBLE); + return schedule_timeout(timeout); +} +EXPORT_SYMBOL(schedule_timeout_interruptible); + +signed long __sched schedule_timeout_uninterruptible(signed long timeout) +{ + set_current_state(TASK_UNINTERRUPTIBLE); + return schedule_timeout(timeout); +} +EXPORT_SYMBOL(schedule_timeout_uninterruptible); + /* Thread ID - the internal kernel "pid" */ asmlinkage long sys_gettid(void) { @@ -1170,8 +1184,7 @@ static long __sched nanosleep_restart(struct restart_block *restart) if (!time_after(expire, now)) return 0; - current->state = TASK_INTERRUPTIBLE; - expire = schedule_timeout(expire - now); + expire = schedule_timeout_interruptible(expire - now); ret = 0; if (expire) { @@ -1199,8 +1212,7 @@ asmlinkage long sys_nanosleep(struct timespec __user *rqtp, struct timespec __us return -EINVAL; expire = timespec_to_jiffies(&t) + (t.tv_sec || t.tv_nsec); - current->state = TASK_INTERRUPTIBLE; - expire = schedule_timeout(expire); + expire = schedule_timeout_interruptible(expire); ret = 0; if (expire) { @@ -1598,10 +1610,8 @@ void msleep(unsigned int msecs) { unsigned long timeout = msecs_to_jiffies(msecs) + 1; - while (timeout) { - set_current_state(TASK_UNINTERRUPTIBLE); - timeout = schedule_timeout(timeout); - } + while (timeout) + timeout = schedule_timeout_uninterruptible(timeout); } EXPORT_SYMBOL(msleep); @@ -1614,10 +1624,8 @@ unsigned long msleep_interruptible(unsigned int msecs) { unsigned long timeout = msecs_to_jiffies(msecs) + 1; - while (timeout && !signal_pending(current)) { - set_current_state(TASK_INTERRUPTIBLE); - timeout = schedule_timeout(timeout); - } + while (timeout && !signal_pending(current)) + timeout = schedule_timeout_interruptible(timeout); return jiffies_to_msecs(timeout); } |