X-Git-Url: https://git.karo-electronics.de/?a=blobdiff_plain;f=kernel%2Fsys.c;h=9a24374c23bc4f69116d264991689b1aaa9c38fe;hb=67d340f440f389e9d56201fb7c7aaa92f262feb1;hp=0a2c8cda9638f3273a11702c1f0721be0662e4aa;hpb=d6e711448137ca3301512cec41a2c2ce852b3d0a;p=mv-sheeva.git diff --git a/kernel/sys.c b/kernel/sys.c index 0a2c8cda963..9a24374c23b 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -16,6 +16,8 @@ #include #include #include +#include +#include #include #include #include @@ -405,6 +407,7 @@ asmlinkage long sys_reboot(int magic1, int magic2, unsigned int cmd, void __user case LINUX_REBOOT_CMD_HALT: notifier_call_chain(&reboot_notifier_list, SYS_HALT, NULL); system_state = SYSTEM_HALT; + device_suspend(PMSG_SUSPEND); device_shutdown(); printk(KERN_EMERG "System halted.\n"); machine_halt(); @@ -415,6 +418,7 @@ asmlinkage long sys_reboot(int magic1, int magic2, unsigned int cmd, void __user case LINUX_REBOOT_CMD_POWER_OFF: notifier_call_chain(&reboot_notifier_list, SYS_POWER_OFF, NULL); system_state = SYSTEM_POWER_OFF; + device_suspend(PMSG_SUSPEND); device_shutdown(); printk(KERN_EMERG "Power down.\n"); machine_power_off(); @@ -431,11 +435,30 @@ asmlinkage long sys_reboot(int magic1, int magic2, unsigned int cmd, void __user notifier_call_chain(&reboot_notifier_list, SYS_RESTART, buffer); system_state = SYSTEM_RESTART; + device_suspend(PMSG_FREEZE); device_shutdown(); printk(KERN_EMERG "Restarting system with command '%s'.\n", buffer); machine_restart(buffer); break; +#ifdef CONFIG_KEXEC + case LINUX_REBOOT_CMD_KEXEC: + { + struct kimage *image; + image = xchg(&kexec_image, 0); + if (!image) { + unlock_kernel(); + return -EINVAL; + } + notifier_call_chain(&reboot_notifier_list, SYS_RESTART, NULL); + system_state = SYSTEM_RESTART; + device_shutdown(); + printk(KERN_EMERG "Starting new kernel\n"); + machine_shutdown(); + machine_kexec(image); + break; + } +#endif #ifdef CONFIG_SOFTWARE_SUSPEND case LINUX_REBOOT_CMD_SW_SUSPEND: { @@ -894,35 +917,69 @@ asmlinkage long sys_times(struct tms __user * tbuf) */ if (tbuf) { struct tms tmp; - struct task_struct *tsk = current; - struct task_struct *t; cputime_t utime, stime, cutime, cstime; - read_lock(&tasklist_lock); - utime = tsk->signal->utime; - stime = tsk->signal->stime; - t = tsk; - do { - utime = cputime_add(utime, t->utime); - stime = cputime_add(stime, t->stime); - t = next_thread(t); - } while (t != tsk); - - /* - * While we have tasklist_lock read-locked, no dying thread - * can be updating current->signal->[us]time. Instead, - * we got their counts included in the live thread loop. - * However, another thread can come in right now and - * do a wait call that updates current->signal->c[us]time. - * To make sure we always see that pair updated atomically, - * we take the siglock around fetching them. - */ - spin_lock_irq(&tsk->sighand->siglock); - cutime = tsk->signal->cutime; - cstime = tsk->signal->cstime; - spin_unlock_irq(&tsk->sighand->siglock); - read_unlock(&tasklist_lock); +#ifdef CONFIG_SMP + if (thread_group_empty(current)) { + /* + * Single thread case without the use of any locks. + * + * We may race with release_task if two threads are + * executing. However, release task first adds up the + * counters (__exit_signal) before removing the task + * from the process tasklist (__unhash_process). + * __exit_signal also acquires and releases the + * siglock which results in the proper memory ordering + * so that the list modifications are always visible + * after the counters have been updated. + * + * If the counters have been updated by the second thread + * but the thread has not yet been removed from the list + * then the other branch will be executing which will + * block on tasklist_lock until the exit handling of the + * other task is finished. + * + * This also implies that the sighand->siglock cannot + * be held by another processor. So we can also + * skip acquiring that lock. + */ + utime = cputime_add(current->signal->utime, current->utime); + stime = cputime_add(current->signal->utime, current->stime); + cutime = current->signal->cutime; + cstime = current->signal->cstime; + } else +#endif + { + /* Process with multiple threads */ + struct task_struct *tsk = current; + struct task_struct *t; + + read_lock(&tasklist_lock); + utime = tsk->signal->utime; + stime = tsk->signal->stime; + t = tsk; + do { + utime = cputime_add(utime, t->utime); + stime = cputime_add(stime, t->stime); + t = next_thread(t); + } while (t != tsk); + + /* + * While we have tasklist_lock read-locked, no dying thread + * can be updating current->signal->[us]time. Instead, + * we got their counts included in the live thread loop. + * However, another thread can come in right now and + * do a wait call that updates current->signal->c[us]time. + * To make sure we always see that pair updated atomically, + * we take the siglock around fetching them. + */ + spin_lock_irq(&tsk->sighand->siglock); + cutime = tsk->signal->cutime; + cstime = tsk->signal->cstime; + spin_unlock_irq(&tsk->sighand->siglock); + read_unlock(&tasklist_lock); + } tmp.tms_utime = cputime_to_clock_t(utime); tmp.tms_stime = cputime_to_clock_t(stime); tmp.tms_cutime = cputime_to_clock_t(cutime); @@ -1225,7 +1282,7 @@ static void groups_sort(struct group_info *group_info) } /* a simple bsearch */ -static int groups_search(struct group_info *group_info, gid_t grp) +int groups_search(struct group_info *group_info, gid_t grp) { int left, right;