X-Git-Url: http://git.madism.org/?p=~madcoder%2Fpwqr.git;a=blobdiff_plain;f=kernel%2Fpwqr.c;h=0d6b42ca187004e797fd1f395908daa5289656d3;hp=7ce0700027f6d3c4a77275feccccd11b6a4924e4;hb=866e56c8f10d718c24e812335b107a05218dc339;hpb=4d4f64ffd9acc95b7c4f816a537d2c1dff8df367 diff --git a/kernel/pwqr.c b/kernel/pwqr.c index 7ce0700..0d6b42c 100644 --- a/kernel/pwqr.c +++ b/kernel/pwqr.c @@ -26,6 +26,7 @@ #include #include #include +#include #include #include #include @@ -39,10 +40,17 @@ #include "pwqr.h" -#define PWQR_UNPARK_DELAY (HZ / 10) #define PWQR_HASH_BITS 5 #define PWQR_HASH_SIZE (1 << PWQR_HASH_BITS) +#define PWQR_UC_DELAY (HZ / 10) +#define PWQR_OC_DELAY (HZ / 20) + +#define PWQR_STATE_NONE 0 +#define PWQR_STATE_UC 1 +#define PWQR_STATE_OC 2 +#define PWQR_STATE_DEAD (-1) + struct pwqr_task_bucket { spinlock_t lock; struct hlist_head tasks; @@ -53,7 +61,7 @@ struct pwqr_sb { struct rcu_head rcu; struct timer_list timer; wait_queue_head_t wqh; - pid_t tgid; + wait_queue_head_t wqh_poll; unsigned concurrency; unsigned registered; @@ -63,7 +71,7 @@ struct pwqr_sb { unsigned parked; unsigned overcommit_wakes; - unsigned dead; + int state; }; struct pwqr_task { @@ -93,22 +101,27 @@ static struct preempt_ops pwqr_preempt_noop_ops; #define pwqr_sb_unlock_irqrestore(sb, flags) \ spin_unlock_irqrestore(&(sb)->wqh.lock, flags) +static inline void pwqr_arm_timer(struct pwqr_sb *sb, int how, int delay) +{ + if (timer_pending(&sb->timer) && sb->state == how) + return; + mod_timer(&sb->timer, jiffies + delay); + sb->state = how; +} + static inline void __pwqr_sb_update_state(struct pwqr_sb *sb, int running_delta) { sb->running += running_delta; - if (sb->running > sb->concurrency) { - /* TODO see ../Documentation/pwqr.adoc */ - } else if (sb->running == sb->concurrency) { - /* do nothing */ - } else if (sb->waiting == 0 && sb->parked) { - if (!timer_pending(&sb->timer)) { - mod_timer(&sb->timer, jiffies + PWQR_UNPARK_DELAY); - } - return; - } - if (timer_pending(&sb->timer)) - del_timer(&sb->timer); + if (sb->running < sb->concurrency && sb->waiting == 0 && sb->parked) { + pwqr_arm_timer(sb, PWQR_STATE_UC, PWQR_UC_DELAY); + } else if (sb->running > sb->concurrency) { + pwqr_arm_timer(sb, PWQR_STATE_OC, PWQR_OC_DELAY); + } else { + sb->state = PWQR_STATE_NONE; + if (!timer_pending(&sb->timer)) + del_timer(&sb->timer); + } } static void pwqr_sb_timer_cb(unsigned long arg) @@ -117,10 +130,13 @@ static void pwqr_sb_timer_cb(unsigned long arg) unsigned long flags; pwqr_sb_lock_irqsave(sb, flags); - if (sb->waiting == 0 && sb->parked && sb->running < sb->concurrency) { + if (sb->running < sb->concurrency && sb->waiting == 0 && sb->parked) { if (sb->overcommit_wakes == 0) wake_up_locked(&sb->wqh); } + if (sb->running > sb->concurrency) { + wake_up_poll(&sb->wqh_poll, POLLIN); + } pwqr_sb_unlock_irqrestore(sb, flags); } @@ -134,8 +150,7 @@ static struct pwqr_sb *pwqr_sb_create(void) kref_init(&sb->kref); init_waitqueue_head(&sb->wqh); - sb->tgid = current->tgid; - sb->concurrency = num_online_cpus(); + sb->concurrency = num_online_cpus(); init_timer(&sb->timer); sb->timer.function = pwqr_sb_timer_cb; sb->timer.data = (unsigned long)sb; @@ -161,6 +176,7 @@ static void pwqr_sb_release(struct kref *kref) struct pwqr_sb *sb = container_of(kref, struct pwqr_sb, kref); del_timer_sync(&sb->timer); + wake_up_poll(&sb->wqh_poll, POLLHUP); call_rcu(&sb->rcu, pwqr_sb_finalize); } static inline void pwqr_sb_put(struct pwqr_sb *sb) @@ -281,7 +297,7 @@ static void pwqr_task_blocked_sched_in(struct preempt_notifier *notifier, int cp struct pwqr_sb *sb = pwqt->sb; unsigned long flags; - if (unlikely(sb->dead)) { + if (unlikely(sb->state < 0)) { pwqr_task_detach(pwqt, sb); pwqr_task_release(pwqt, true); return; @@ -296,11 +312,11 @@ static void pwqr_task_blocked_sched_in(struct preempt_notifier *notifier, int cp static void pwqr_task_sched_out(struct preempt_notifier *notifier, struct task_struct *next) { - struct pwqr_task *pwqt = container_of(notifier, struct pwqr_task, notifier); - struct pwqr_sb *sb = pwqt->sb; + struct pwqr_task *pwqt = container_of(notifier, struct pwqr_task, notifier); + struct pwqr_sb *sb = pwqt->sb; struct task_struct *p = pwqt->task; - if (unlikely(p->state & TASK_DEAD) || unlikely(sb->dead)) { + if (unlikely(p->state & TASK_DEAD) || unlikely(sb->state < 0)) { pwqr_task_detach(pwqt, sb); pwqr_task_release(pwqt, true); return; @@ -350,16 +366,83 @@ static int pwqr_release(struct inode *inode, struct file *filp) unsigned long flags; pwqr_sb_lock_irqsave(sb, flags); - sb->dead = true; + sb->state = PWQR_STATE_DEAD; pwqr_sb_unlock_irqrestore(sb, flags); wake_up_all(&sb->wqh); pwqr_sb_put(sb); return 0; } +static unsigned int pwqr_poll(struct file *filp, poll_table *wait) +{ + struct pwqr_sb *sb = filp->private_data; + unsigned int events = 0; + unsigned long flags; + + poll_wait(filp, &sb->wqh_poll, wait); + + pwqr_sb_lock_irqsave(sb, flags); + if (sb->running > sb->concurrency) + events |= POLLIN; + if (sb->state < 0) + events |= POLLHUP; + pwqr_sb_unlock_irqrestore(sb, flags); + + return events; +} + +static inline ssize_t pwqr_sb_read(struct pwqr_sb *sb, int no_wait, u32 *cnt) +{ + DECLARE_WAITQUEUE(wait, current); + ssize_t rc = -EAGAIN; + + spin_lock_irq(&sb->wqh.lock); + if (sb->running > sb->concurrency) { + rc = 0; + } else if (!no_wait) { + add_wait_queue(&sb->wqh_poll, &wait); + for (;;) { + set_current_state(TASK_INTERRUPTIBLE); + if (sb->running > sb->concurrency) { + rc = 0; + break; + } + if (signal_pending(current)) { + rc = -ERESTARTSYS; + break; + } + spin_unlock_irq(&sb->wqh.lock); + schedule(); + spin_lock_irq(&sb->wqh.lock); + } + remove_wait_queue(&sb->wqh_poll, &wait); + __set_current_state(TASK_RUNNING); + } + if (likely(rc == 0)) + *cnt = sb->running - sb->concurrency; + spin_unlock_irq(&sb->wqh.lock); + + return rc; +} + +static ssize_t +pwqr_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos) +{ + struct pwqr_sb *sb = filp->private_data; + u32 cnt = 0; + ssize_t rc; + + if (count < sizeof(cnt)) + return -EINVAL; + rc = pwqr_sb_read(sb, filp->f_flags & O_NONBLOCK, &cnt); + if (rc < 0) + return rc; + return put_user(cnt, (u32 __user *)buf) ? -EFAULT : sizeof(cnt); +} + static long do_pwqr_wait(struct pwqr_sb *sb, struct pwqr_task *pwqt, - int is_wait, struct pwqr_ioc_wait __user *arg) + int is_wait, struct pwqr_ioc_wait __user *arg) { unsigned long flags; struct pwqr_ioc_wait wait; @@ -400,9 +483,8 @@ do_pwqr_wait(struct pwqr_sb *sb, struct pwqr_task *pwqt, } /* @ see */ - if (likely(!sb->dead)) { + if (likely(sb->state >= 0)) { DEFINE_WAIT(__wait); - __wait.flags |= WQ_FLAG_EXCLUSIVE; if (is_wait) { @@ -413,9 +495,9 @@ do_pwqr_wait(struct pwqr_sb *sb, struct pwqr_task *pwqt, __add_wait_queue_tail(&sb->wqh, &__wait); } __pwqr_sb_update_state(sb, -1); - set_current_state(TASK_INTERRUPTIBLE); do { + set_current_state(TASK_INTERRUPTIBLE); if (sb->overcommit_wakes) break; if (signal_pending(current)) { @@ -429,17 +511,17 @@ do_pwqr_wait(struct pwqr_sb *sb, struct pwqr_task *pwqt, break; if (sb->running + sb->waiting < sb->concurrency) break; - } while (likely(!sb->dead)); + } while (likely(sb->state >= 0)); __remove_wait_queue(&sb->wqh, &__wait); __set_current_state(TASK_RUNNING); - if (is_wait) { sb->waiting--; } else { sb->parked--; } __pwqr_sb_update_state(sb, 1); + if (sb->overcommit_wakes) sb->overcommit_wakes--; if (sb->waiting + sb->running > sb->concurrency) @@ -447,7 +529,7 @@ do_pwqr_wait(struct pwqr_sb *sb, struct pwqr_task *pwqt, } out_unlock: - if (unlikely(sb->dead)) + if (unlikely(sb->state < 0)) rc = -EBADFD; pwqr_sb_unlock_irqrestore(sb, flags); out: @@ -543,14 +625,11 @@ static long do_pwqr_wake(struct pwqr_sb *sb, int oc, int count) static long pwqr_ioctl(struct file *filp, unsigned command, unsigned long arg) { - struct pwqr_sb *sb = filp->private_data; + struct pwqr_sb *sb = filp->private_data; struct task_struct *task = current; - struct pwqr_task *pwqt; + struct pwqr_task *pwqt; int rc = 0; - if (sb->tgid != current->tgid) - return -EBADFD; - switch (command) { case PWQR_GET_CONC: return sb->concurrency; @@ -593,7 +672,7 @@ static long pwqr_ioctl(struct file *filp, unsigned command, unsigned long arg) break; } - if (unlikely(sb->dead)) { + if (unlikely(sb->state < 0)) { pwqr_task_detach(pwqt, pwqt->sb); return -EBADFD; } @@ -604,6 +683,9 @@ static const struct file_operations pwqr_dev_fops = { .owner = THIS_MODULE, .open = pwqr_open, .release = pwqr_release, + .poll = pwqr_poll, + .read = pwqr_read, + .llseek = noop_llseek, .unlocked_ioctl = pwqr_ioctl, #ifdef CONFIG_COMPAT .compat_ioctl = pwqr_ioctl,