Pull scheduler fix from Ingo Molnar: "A delayacct statistics correctness fix" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: delayacct: Account blkio completion on the correct task
Unified · Split
| @@ -71,7 +71,7 @@ extern void delayacct_init(void); · 70 unmodified lines | ||
| 71 | 71 | extern void __delayacct_tsk_init(struct task_struct *); |
| 72 | 72 | extern void __delayacct_tsk_exit(struct task_struct *); |
| 73 | 73 | extern void __delayacct_blkio_start(void); |
| 74 | −extern void __delayacct_blkio_end(void); | |
| 74 | +extern void __delayacct_blkio_end(struct task_struct *); | |
| 75 | 75 | extern int __delayacct_add_tsk(struct taskstats *, struct task_struct *); |
| 76 | 76 | extern __u64 __delayacct_blkio_ticks(struct task_struct *); |
| 77 | 77 | extern void __delayacct_freepages_start(void); |
| @@ -122,10 +122,10 @@ static inline void delayacct_blkio_start(void) · 44 unmodified lines | ||
| 122 | 122 | __delayacct_blkio_start(); |
| 123 | 123 | } |
| 124 | 124 | |
| 125 | −static inline void delayacct_blkio_end(void) | |
| 125 | +static inline void delayacct_blkio_end(struct task_struct *p) | |
| 126 | 126 | { |
| 127 | 127 | if (current->delays) |
| 128 | − __delayacct_blkio_end(); | |
| 128 | + __delayacct_blkio_end(p); | |
| 129 | 129 | delayacct_clear_flag(DELAYACCT_PF_BLKIO); |
| 130 | 130 | } |
| 131 | 131 | |
| @@ -169,7 +169,7 @@ static inline void delayacct_tsk_free(struct task_struct *tsk) · 37 unmodified lines | ||
| 169 | 169 | {} |
| 170 | 170 | static inline void delayacct_blkio_start(void) |
| 171 | 171 | {} |
| 172 | −static inline void delayacct_blkio_end(void) | |
| 172 | +static inline void delayacct_blkio_end(struct task_struct *p) | |
| 173 | 173 | {} |
| 174 | 174 | static inline int delayacct_add_tsk(struct taskstats *d, |
| 175 | 175 | struct task_struct *tsk) |
| @@ -51,16 +51,16 @@ void __delayacct_tsk_init(struct task_struct *tsk) · 50 unmodified lines | ||
| 51 | 51 | * Finish delay accounting for a statistic using its timestamps (@start), |
| 52 | 52 | * accumalator (@total) and @count |
| 53 | 53 | */ |
| 54 | −static void delayacct_end(u64 *start, u64 *total, u32 *count) | |
| 54 | +static void delayacct_end(spinlock_t *lock, u64 *start, u64 *total, u32 *count) | |
| 55 | 55 | { |
| 56 | 56 | s64 ns = ktime_get_ns() - *start; |
| 57 | 57 | unsigned long flags; |
| 58 | 58 | |
| 59 | 59 | if (ns > 0) { |
| 60 | − spin_lock_irqsave(¤t->delays->lock, flags); | |
| 60 | + spin_lock_irqsave(lock, flags); | |
| 61 | 61 | *total += ns; |
| 62 | 62 | (*count)++; |
| 63 | − spin_unlock_irqrestore(¤t->delays->lock, flags); | |
| 63 | + spin_unlock_irqrestore(lock, flags); | |
| 64 | 64 | } |
| 65 | 65 | } |
| 66 | 66 | |
| @@ -69,17 +69,25 @@ void __delayacct_blkio_start(void) · 2 unmodified lines | ||
| 69 | 69 | current->delays->blkio_start = ktime_get_ns(); |
| 70 | 70 | } |
| 71 | 71 | |
| 72 | −void __delayacct_blkio_end(void) | |
| 72 | +/* | |
| 73 | + * We cannot rely on the `current` macro, as we haven't yet switched back to | |
| 74 | + * the process being woken. | |
| 75 | + */ | |
| 76 | +void __delayacct_blkio_end(struct task_struct *p) | |
| 73 | 77 | { |
| 74 | − if (current->delays->flags & DELAYACCT_PF_SWAPIN) | |
| 75 | − /* Swapin block I/O */ | |
| 76 | − delayacct_end(¤t->delays->blkio_start, | |
| 77 | − ¤t->delays->swapin_delay, | |
| 78 | − ¤t->delays->swapin_count); | |
| 79 | − else /* Other block I/O */ | |
| 80 | − delayacct_end(¤t->delays->blkio_start, | |
| 81 | − ¤t->delays->blkio_delay, | |
| 82 | − ¤t->delays->blkio_count); | |
| 78 | + struct task_delay_info *delays = p->delays; | |
| 79 | + u64 *total; | |
| 80 | + u32 *count; | |
| 81 | + | |
| 82 | + if (p->delays->flags & DELAYACCT_PF_SWAPIN) { | |
| 83 | + total = &delays->swapin_delay; | |
| 84 | + count = &delays->swapin_count; | |
| 85 | + } else { | |
| 86 | + total = &delays->blkio_delay; | |
| 87 | + count = &delays->blkio_count; | |
| 88 | + } | |
| 89 | + | |
| 90 | + delayacct_end(&delays->lock, &delays->blkio_start, total, count); | |
| 83 | 91 | } |
| 84 | 92 | |
| 85 | 93 | int __delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk) |
| @@ -153,8 +161,10 @@ void __delayacct_freepages_start(void) · 67 unmodified lines | ||
| 153 | 161 | |
| 154 | 162 | void __delayacct_freepages_end(void) |
| 155 | 163 | { |
| 156 | − delayacct_end(¤t->delays->freepages_start, | |
| 157 | − ¤t->delays->freepages_delay, | |
| 158 | − ¤t->delays->freepages_count); | |
| 164 | + delayacct_end( | |
| 165 | + ¤t->delays->lock, | |
| 166 | + ¤t->delays->freepages_start, | |
| 167 | + ¤t->delays->freepages_delay, | |
| 168 | + ¤t->delays->freepages_count); | |
| 159 | 169 | } |
| 160 | 170 | |
| @@ -2056,7 +2056,7 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) · 2055 unmodified lines | ||
| 2056 | 2056 | p->state = TASK_WAKING; |
| 2057 | 2057 | |
| 2058 | 2058 | if (p->in_iowait) { |
| 2059 | − delayacct_blkio_end(); | |
| 2059 | + delayacct_blkio_end(p); | |
| 2060 | 2060 | atomic_dec(&task_rq(p)->nr_iowait); |
| 2061 | 2061 | } |
| 2062 | 2062 | |
| @@ -2069,7 +2069,7 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) · 6 unmodified lines | ||
| 2069 | 2069 | #else /* CONFIG_SMP */ |
| 2070 | 2070 | |
| 2071 | 2071 | if (p->in_iowait) { |
| 2072 | − delayacct_blkio_end(); | |
| 2072 | + delayacct_blkio_end(p); | |
| 2073 | 2073 | atomic_dec(&task_rq(p)->nr_iowait); |
| 2074 | 2074 | } |
| 2075 | 2075 | |
| @@ -2122,7 +2122,7 @@ static void try_to_wake_up_local(struct task_struct *p, struct rq_flags *rf) · 46 unmodified lines | ||
| 2122 | 2122 | |
| 2123 | 2123 | if (!task_on_rq_queued(p)) { |
| 2124 | 2124 | if (p->in_iowait) { |
| 2125 | − delayacct_blkio_end(); | |
| 2125 | + delayacct_blkio_end(p); | |
| 2126 | 2126 | atomic_dec(&rq->nr_iowait); |
| 2127 | 2127 | } |
| 2128 | 2128 | ttwu_activate(rq, p, ENQUEUE_WAKEUP | ENQUEUE_NOCLOCK); |