X-Git-Url: http://git.rot13.org/?a=blobdiff_plain;f=kernel%2Fexit.c;h=6c2eeb8f6390c1ae1daeb3b12ecd3aa974b3c599;hb=74e6c8c394ca2126a60e97bc1142ec2d91761e9a;hp=223a8802b665e8f04b8f3174c1634a48923b3403;hpb=fef23e7fbb11a0a78cd61935f7056bc2b237995a;p=powerpc.git diff --git a/kernel/exit.c b/kernel/exit.c index 223a8802b6..6c2eeb8f63 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -29,6 +29,7 @@ #include #include #include +#include #include #include #include @@ -50,15 +51,85 @@ static void __unhash_process(struct task_struct *p) { nr_threads--; detach_pid(p, PIDTYPE_PID); - detach_pid(p, PIDTYPE_TGID); if (thread_group_leader(p)) { detach_pid(p, PIDTYPE_PGID); detach_pid(p, PIDTYPE_SID); - if (p->pid) - __get_cpu_var(process_counts)--; + + list_del_init(&p->tasks); + __get_cpu_var(process_counts)--; + } + list_del_rcu(&p->thread_group); + remove_parent(p); +} + +/* + * This function expects the tasklist_lock write-locked. + */ +static void __exit_signal(struct task_struct *tsk) +{ + struct signal_struct *sig = tsk->signal; + struct sighand_struct *sighand; + + BUG_ON(!sig); + BUG_ON(!atomic_read(&sig->count)); + + rcu_read_lock(); + sighand = rcu_dereference(tsk->sighand); + spin_lock(&sighand->siglock); + + posix_cpu_timers_exit(tsk); + if (atomic_dec_and_test(&sig->count)) + posix_cpu_timers_exit_group(tsk); + else { + /* + * If there is any task waiting for the group exit + * then notify it: + */ + if (sig->group_exit_task && atomic_read(&sig->count) == sig->notify_count) { + wake_up_process(sig->group_exit_task); + sig->group_exit_task = NULL; + } + if (tsk == sig->curr_target) + sig->curr_target = next_thread(tsk); + /* + * Accumulate here the counters for all threads but the + * group leader as they die, so they can be added into + * the process-wide totals when those are taken. + * The group leader stays around as a zombie as long + * as there are other threads. When it gets reaped, + * the exit.c code will add its counts into these totals. + * We won't ever get here for the group leader, since it + * will have been the last reference on the signal_struct. + */ + sig->utime = cputime_add(sig->utime, tsk->utime); + sig->stime = cputime_add(sig->stime, tsk->stime); + sig->min_flt += tsk->min_flt; + sig->maj_flt += tsk->maj_flt; + sig->nvcsw += tsk->nvcsw; + sig->nivcsw += tsk->nivcsw; + sig->sched_time += tsk->sched_time; + sig = NULL; /* Marker for below. */ } - REMOVE_LINKS(p); + __unhash_process(tsk); + + tsk->signal = NULL; + tsk->sighand = NULL; + spin_unlock(&sighand->siglock); + rcu_read_unlock(); + + __cleanup_sighand(sighand); + clear_tsk_thread_flag(tsk,TIF_SIGPENDING); + flush_sigqueue(&tsk->pending); + if (sig) { + flush_sigqueue(&sig->shared_pending); + __cleanup_signal(sig); + } +} + +static void delayed_put_task_struct(struct rcu_head *rhp) +{ + put_task_struct(container_of(rhp, struct task_struct, rcu)); } void release_task(struct task_struct * p) @@ -67,21 +138,14 @@ void release_task(struct task_struct * p) task_t *leader; struct dentry *proc_dentry; -repeat: +repeat: atomic_dec(&p->user->processes); spin_lock(&p->proc_lock); proc_dentry = proc_pid_unhash(p); write_lock_irq(&tasklist_lock); - if (unlikely(p->ptrace)) - __ptrace_unlink(p); + ptrace_unlink(p); BUG_ON(!list_empty(&p->ptrace_list) || !list_empty(&p->ptrace_children)); __exit_signal(p); - /* - * Note that the fastpath in sys_times depends on __exit_signal having - * updated the counters before a task is removed from the tasklist of - * the process by __unhash_process. - */ - __unhash_process(p); /* * If we are the last non-leader member of the thread @@ -109,28 +173,13 @@ repeat: spin_unlock(&p->proc_lock); proc_pid_flush(proc_dentry); release_thread(p); - put_task_struct(p); + call_rcu(&p->rcu, delayed_put_task_struct); p = leader; if (unlikely(zap_leader)) goto repeat; } -/* we are using it only for SMP init */ - -void unhash_process(struct task_struct *p) -{ - struct dentry *proc_dentry; - - spin_lock(&p->proc_lock); - proc_dentry = proc_pid_unhash(p); - write_lock_irq(&tasklist_lock); - __unhash_process(p); - write_unlock_irq(&tasklist_lock); - spin_unlock(&p->proc_lock); - proc_pid_flush(proc_dentry); -} - /* * This checks not only the pgrp, but falls back on the pid if no * satisfactory pgrp is found. I dunno - gdb doesn't work correctly @@ -238,10 +287,10 @@ static void reparent_to_init(void) ptrace_unlink(current); /* Reparent to init */ - REMOVE_LINKS(current); + remove_parent(current); current->parent = child_reaper; current->real_parent = child_reaper; - SET_LINKS(current); + add_parent(current); /* Set the exit signal to SIGCHLD so we signal init on exit */ current->exit_signal = SIGCHLD; @@ -538,13 +587,13 @@ static void exit_mm(struct task_struct * tsk) mmput(mm); } -static inline void choose_new_parent(task_t *p, task_t *reaper, task_t *child_reaper) +static inline void choose_new_parent(task_t *p, task_t *reaper) { /* * Make sure we're not reparenting to ourselves and that * the parent is not a zombie. */ - BUG_ON(p == reaper || reaper->exit_state >= EXIT_ZOMBIE); + BUG_ON(p == reaper || reaper->exit_state); p->real_parent = reaper; } @@ -569,9 +618,9 @@ static void reparent_thread(task_t *p, task_t *father, int traced) * anyway, so let go of it. */ p->ptrace = 0; - list_del_init(&p->sibling); + remove_parent(p); p->parent = p->real_parent; - list_add_tail(&p->sibling, &p->parent->children); + add_parent(p); /* If we'd notified the old parent about this child's death, * also notify the new parent. @@ -645,7 +694,7 @@ static void forget_original_parent(struct task_struct * father, if (father == p->real_parent) { /* reparent with a reaper, real father it's us */ - choose_new_parent(p, reaper, child_reaper); + choose_new_parent(p, reaper); reparent_thread(p, father, 0); } else { /* reparent ptraced task to its real parent */ @@ -666,7 +715,7 @@ static void forget_original_parent(struct task_struct * father, } list_for_each_safe(_p, _n, &father->ptrace_children) { p = list_entry(_p,struct task_struct,ptrace_list); - choose_new_parent(p, reaper, child_reaper); + choose_new_parent(p, reaper); reparent_thread(p, father, 1); } } @@ -920,13 +969,6 @@ asmlinkage long sys_exit(int error_code) do_exit((error_code&0xff)<<8); } -task_t fastcall *next_thread(const task_t *p) -{ - return pid_task(p->pids[PIDTYPE_TGID].pid_list.next, PIDTYPE_TGID); -} - -EXPORT_SYMBOL(next_thread); - /* * Take down every thread in the group. This is called by fatal signals * as well as by sys_exit_group (below). @@ -941,7 +983,6 @@ do_group_exit(int exit_code) else if (!thread_group_empty(current)) { struct signal_struct *const sig = current->signal; struct sighand_struct *const sighand = current->sighand; - read_lock(&tasklist_lock); spin_lock_irq(&sighand->siglock); if (sig->flags & SIGNAL_GROUP_EXIT) /* Another thread got here before we took the lock. */ @@ -951,7 +992,6 @@ do_group_exit(int exit_code) zap_other_threads(current); } spin_unlock_irq(&sighand->siglock); - read_unlock(&tasklist_lock); } do_exit(exit_code); @@ -1281,7 +1321,7 @@ bail_ref: /* move to end of parent's list to avoid starvation */ remove_parent(p); - add_parent(p, p->parent); + add_parent(p); write_unlock_irq(&tasklist_lock);