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author | Linus Torvalds <torvalds@linux-foundation.org> | 2015-08-04 17:49:08 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-08-04 17:49:08 +0200 |
commit | 1ddc6dd855f01977e9e1795037fca1c8be028d24 (patch) | |
tree | d4e2cfd4ae6cb1717ab5fb1633946b9138db87ba /drivers/xen | |
parent | Merge branch 'rc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mmar... (diff) | |
parent | xen/events/fifo: Handle linked events when closing a port (diff) | |
download | linux-1ddc6dd855f01977e9e1795037fca1c8be028d24.tar.xz linux-1ddc6dd855f01977e9e1795037fca1c8be028d24.zip |
Merge tag 'for-linus-4.2-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen bug fixes from David Vrabel:
- don't lose interrupts when offlining CPUs
- fix gntdev oops during unmap
- drop the balloon lock occasionally to allow domain create/destroy
* tag 'for-linus-4.2-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen/events/fifo: Handle linked events when closing a port
xen: release lock occasionally during ballooning
xen/gntdevt: Fix race condition in gntdev_release()
Diffstat (limited to 'drivers/xen')
-rw-r--r-- | drivers/xen/balloon.c | 15 | ||||
-rw-r--r-- | drivers/xen/events/events_base.c | 10 | ||||
-rw-r--r-- | drivers/xen/events/events_fifo.c | 45 | ||||
-rw-r--r-- | drivers/xen/events/events_internal.h | 7 | ||||
-rw-r--r-- | drivers/xen/gntdev.c | 2 |
5 files changed, 62 insertions, 17 deletions
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c index fd933695f232..bf4a23c7c591 100644 --- a/drivers/xen/balloon.c +++ b/drivers/xen/balloon.c @@ -472,7 +472,7 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp) } /* - * We avoid multiple worker processes conflicting via the balloon mutex. + * As this is a work item it is guaranteed to run as a single instance only. * We may of course race updates of the target counts (which are protected * by the balloon lock), or with changes to the Xen hard limit, but we will * recover from these in time. @@ -482,9 +482,10 @@ static void balloon_process(struct work_struct *work) enum bp_state state = BP_DONE; long credit; - mutex_lock(&balloon_mutex); do { + mutex_lock(&balloon_mutex); + credit = current_credit(); if (credit > 0) { @@ -499,17 +500,15 @@ static void balloon_process(struct work_struct *work) state = update_schedule(state); -#ifndef CONFIG_PREEMPT - if (need_resched()) - schedule(); -#endif + mutex_unlock(&balloon_mutex); + + cond_resched(); + } while (credit && state == BP_DONE); /* Schedule more work if there is some still to be done. */ if (state == BP_EAGAIN) schedule_delayed_work(&balloon_worker, balloon_stats.schedule_delay * HZ); - - mutex_unlock(&balloon_mutex); } /* Resets the Xen limit, sets new target, and kicks off processing. */ diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c index 96093ae369a5..1495eccb1617 100644 --- a/drivers/xen/events/events_base.c +++ b/drivers/xen/events/events_base.c @@ -452,10 +452,12 @@ static void xen_free_irq(unsigned irq) irq_free_desc(irq); } -static void xen_evtchn_close(unsigned int port) +static void xen_evtchn_close(unsigned int port, unsigned int cpu) { struct evtchn_close close; + xen_evtchn_op_close(port, cpu); + close.port = port; if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0) BUG(); @@ -544,7 +546,7 @@ out: err: pr_err("irq%d: Failed to set port to irq mapping (%d)\n", irq, rc); - xen_evtchn_close(evtchn); + xen_evtchn_close(evtchn, NR_CPUS); return 0; } @@ -565,7 +567,7 @@ static void shutdown_pirq(struct irq_data *data) return; mask_evtchn(evtchn); - xen_evtchn_close(evtchn); + xen_evtchn_close(evtchn, cpu_from_evtchn(evtchn)); xen_irq_info_cleanup(info); } @@ -609,7 +611,7 @@ static void __unbind_from_irq(unsigned int irq) if (VALID_EVTCHN(evtchn)) { unsigned int cpu = cpu_from_irq(irq); - xen_evtchn_close(evtchn); + xen_evtchn_close(evtchn, cpu); switch (type_from_irq(irq)) { case IRQT_VIRQ: diff --git a/drivers/xen/events/events_fifo.c b/drivers/xen/events/events_fifo.c index ed673e1acd61..6df8aac966b9 100644 --- a/drivers/xen/events/events_fifo.c +++ b/drivers/xen/events/events_fifo.c @@ -255,6 +255,12 @@ static void evtchn_fifo_unmask(unsigned port) } } +static bool evtchn_fifo_is_linked(unsigned port) +{ + event_word_t *word = event_word_from_port(port); + return sync_test_bit(EVTCHN_FIFO_BIT(LINKED, word), BM(word)); +} + static uint32_t clear_linked(volatile event_word_t *word) { event_word_t new, old, w; @@ -281,7 +287,8 @@ static void handle_irq_for_port(unsigned port) static void consume_one_event(unsigned cpu, struct evtchn_fifo_control_block *control_block, - unsigned priority, unsigned long *ready) + unsigned priority, unsigned long *ready, + bool drop) { struct evtchn_fifo_queue *q = &per_cpu(cpu_queue, cpu); uint32_t head; @@ -313,13 +320,15 @@ static void consume_one_event(unsigned cpu, if (head == 0) clear_bit(priority, ready); - if (evtchn_fifo_is_pending(port) && !evtchn_fifo_is_masked(port)) - handle_irq_for_port(port); + if (evtchn_fifo_is_pending(port) && !evtchn_fifo_is_masked(port)) { + if (likely(!drop)) + handle_irq_for_port(port); + } q->head[priority] = head; } -static void evtchn_fifo_handle_events(unsigned cpu) +static void __evtchn_fifo_handle_events(unsigned cpu, bool drop) { struct evtchn_fifo_control_block *control_block; unsigned long ready; @@ -331,11 +340,16 @@ static void evtchn_fifo_handle_events(unsigned cpu) while (ready) { q = find_first_bit(&ready, EVTCHN_FIFO_MAX_QUEUES); - consume_one_event(cpu, control_block, q, &ready); + consume_one_event(cpu, control_block, q, &ready, drop); ready |= xchg(&control_block->ready, 0); } } +static void evtchn_fifo_handle_events(unsigned cpu) +{ + __evtchn_fifo_handle_events(cpu, false); +} + static void evtchn_fifo_resume(void) { unsigned cpu; @@ -371,6 +385,26 @@ static void evtchn_fifo_resume(void) event_array_pages = 0; } +static void evtchn_fifo_close(unsigned port, unsigned int cpu) +{ + if (cpu == NR_CPUS) + return; + + get_online_cpus(); + if (cpu_online(cpu)) { + if (WARN_ON(irqs_disabled())) + goto out; + + while (evtchn_fifo_is_linked(port)) + cpu_relax(); + } else { + __evtchn_fifo_handle_events(cpu, true); + } + +out: + put_online_cpus(); +} + static const struct evtchn_ops evtchn_ops_fifo = { .max_channels = evtchn_fifo_max_channels, .nr_channels = evtchn_fifo_nr_channels, @@ -384,6 +418,7 @@ static const struct evtchn_ops evtchn_ops_fifo = { .unmask = evtchn_fifo_unmask, .handle_events = evtchn_fifo_handle_events, .resume = evtchn_fifo_resume, + .close = evtchn_fifo_close, }; static int evtchn_fifo_alloc_control_block(unsigned cpu) diff --git a/drivers/xen/events/events_internal.h b/drivers/xen/events/events_internal.h index 50c2050a1e32..d18e12315ec0 100644 --- a/drivers/xen/events/events_internal.h +++ b/drivers/xen/events/events_internal.h @@ -68,6 +68,7 @@ struct evtchn_ops { bool (*test_and_set_mask)(unsigned port); void (*mask)(unsigned port); void (*unmask)(unsigned port); + void (*close)(unsigned port, unsigned cpu); void (*handle_events)(unsigned cpu); void (*resume)(void); @@ -145,6 +146,12 @@ static inline void xen_evtchn_resume(void) evtchn_ops->resume(); } +static inline void xen_evtchn_op_close(unsigned port, unsigned cpu) +{ + if (evtchn_ops->close) + return evtchn_ops->close(port, cpu); +} + void xen_evtchn_2l_init(void); int xen_evtchn_fifo_init(void); diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c index 67b9163db718..0dbb222daaf1 100644 --- a/drivers/xen/gntdev.c +++ b/drivers/xen/gntdev.c @@ -568,12 +568,14 @@ static int gntdev_release(struct inode *inode, struct file *flip) pr_debug("priv %p\n", priv); + mutex_lock(&priv->lock); while (!list_empty(&priv->maps)) { map = list_entry(priv->maps.next, struct grant_map, next); list_del(&map->next); gntdev_put_map(NULL /* already removed */, map); } WARN_ON(!list_empty(&priv->freeable_maps)); + mutex_unlock(&priv->lock); if (use_ptemod) mmu_notifier_unregister(&priv->mn, priv->mm); |