diff options
Diffstat (limited to 'mm/backing-dev.c')
| -rw-r--r-- | mm/backing-dev.c | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/mm/backing-dev.c b/mm/backing-dev.c index d3ca2b3..bd6a6ca 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -10,6 +10,7 @@ #include <linux/module.h> #include <linux/writeback.h> #include <linux/device.h> +#include <linux/slab.h> #include <trace/events/writeback.h> static atomic_long_t bdi_seq = ATOMIC_LONG_INIT(0); @@ -221,12 +222,63 @@ static ssize_t max_ratio_store(struct device *dev, } BDI_SHOW(max_ratio, bdi->max_ratio) +static ssize_t cpu_list_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t count) +{ + struct backing_dev_info *bdi = dev_get_drvdata(dev); + struct bdi_writeback *wb = &bdi->wb; + cpumask_var_t newmask; + ssize_t ret; + struct task_struct *task; + + if (!alloc_cpumask_var(&newmask, GFP_KERNEL)) + return -ENOMEM; + + ret = cpulist_parse(buf, newmask); + if (!ret) { + spin_lock_bh(&bdi->wb_lock); + task = wb->task; + if (task) + get_task_struct(task); + spin_unlock_bh(&bdi->wb_lock); + + mutex_lock(&bdi->flusher_cpumask_lock); + if (task) { + ret = set_cpus_allowed_ptr(task, newmask); + put_task_struct(task); + } + if (ret == 0) { + cpumask_copy(bdi->flusher_cpumask, newmask); + ret = count; + } + mutex_unlock(&bdi->flusher_cpumask_lock); + + } + free_cpumask_var(newmask); + + return ret; +} + +static ssize_t cpu_list_show(struct device *dev, + struct device_attribute *attr, char *page) +{ + struct backing_dev_info *bdi = dev_get_drvdata(dev); + ssize_t ret; + + mutex_lock(&bdi->flusher_cpumask_lock); + ret = cpulist_scnprintf(page, PAGE_SIZE-1, bdi->flusher_cpumask); + mutex_unlock(&bdi->flusher_cpumask_lock); + + return ret; +} + #define __ATTR_RW(attr) __ATTR(attr, 0644, attr##_show, attr##_store) static struct device_attribute bdi_dev_attrs[] = { __ATTR_RW(read_ahead_kb), __ATTR_RW(min_ratio), __ATTR_RW(max_ratio), + __ATTR_RW(cpu_list), __ATTR_NULL, }; @@ -428,6 +480,7 @@ static int bdi_forker_thread(void *ptr) writeback_inodes_wb(&bdi->wb, 1024, WB_REASON_FORKER_THREAD); } else { + int ret; /* * The spinlock makes sure we do not lose * wake-ups when racing with 'bdi_queue_work()'. @@ -437,6 +490,14 @@ static int bdi_forker_thread(void *ptr) spin_lock_bh(&bdi->wb_lock); bdi->wb.task = task; spin_unlock_bh(&bdi->wb_lock); + mutex_lock(&bdi->flusher_cpumask_lock); + ret = set_cpus_allowed_ptr(task, + bdi->flusher_cpumask); + mutex_unlock(&bdi->flusher_cpumask_lock); + if (ret) + printk_once("%s: failed to bind flusher" + " thread %s, error %d\n", + __func__, task->comm, ret); wake_up_process(task); } bdi_clear_pending(bdi); @@ -509,6 +570,17 @@ int bdi_register(struct backing_dev_info *bdi, struct device *parent, dev_name(dev)); if (IS_ERR(wb->task)) return PTR_ERR(wb->task); + } else { + int node; + /* + * Set up a default cpumask for the flusher threads that + * includes all cpus on the same numa node as the device. + * The mask may be overridden via sysfs. + */ + node = dev_to_node(bdi->dev); + if (node != NUMA_NO_NODE) + cpumask_copy(bdi->flusher_cpumask, + cpumask_of_node(node)); } bdi_debug_register(bdi, dev_name(dev)); @@ -634,6 +706,15 @@ int bdi_init(struct backing_dev_info *bdi) bdi_wb_init(&bdi->wb, bdi); + if (!bdi_cap_flush_forker(bdi)) { + bdi->flusher_cpumask = kmalloc(sizeof(cpumask_t), GFP_KERNEL); + if (!bdi->flusher_cpumask) + return -ENOMEM; + cpumask_setall(bdi->flusher_cpumask); + mutex_init(&bdi->flusher_cpumask_lock); + } else + bdi->flusher_cpumask = NULL; + for (i = 0; i < NR_BDI_STAT_ITEMS; i++) { err = percpu_counter_init(&bdi->bdi_stat[i], 0); if (err) @@ -656,6 +737,7 @@ int bdi_init(struct backing_dev_info *bdi) err: while (i--) percpu_counter_destroy(&bdi->bdi_stat[i]); + kfree(bdi->flusher_cpumask); } return err; @@ -683,6 +765,8 @@ void bdi_destroy(struct backing_dev_info *bdi) bdi_unregister(bdi); + kfree(bdi->flusher_cpumask); + /* * If bdi_unregister() had already been called earlier, the * wakeup_timer could still be armed because bdi_prune_sb() |
