laptop-mode: Make flushes per-device
[safe/jmp/linux-2.6] / block / blk-cgroup.c
index 4ef78d3..9af7257 100644 (file)
 #include <linux/ioprio.h>
 #include <linux/seq_file.h>
 #include <linux/kdev_t.h>
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/blkdev.h>
 #include "blk-cgroup.h"
 
-extern void cfq_unlink_blkio_group(void *, struct blkio_group *);
+static DEFINE_SPINLOCK(blkio_list_lock);
+static LIST_HEAD(blkio_list);
 
 struct blkio_cgroup blkio_root_cgroup = { .weight = 2*BLKIO_WEIGHT_DEFAULT };
+EXPORT_SYMBOL_GPL(blkio_root_cgroup);
+
+static struct cgroup_subsys_state *blkiocg_create(struct cgroup_subsys *,
+                                                 struct cgroup *);
+static int blkiocg_can_attach(struct cgroup_subsys *, struct cgroup *,
+                             struct task_struct *, bool);
+static void blkiocg_attach(struct cgroup_subsys *, struct cgroup *,
+                          struct cgroup *, struct task_struct *, bool);
+static void blkiocg_destroy(struct cgroup_subsys *, struct cgroup *);
+static int blkiocg_populate(struct cgroup_subsys *, struct cgroup *);
+
+struct cgroup_subsys blkio_subsys = {
+       .name = "blkio",
+       .create = blkiocg_create,
+       .can_attach = blkiocg_can_attach,
+       .attach = blkiocg_attach,
+       .destroy = blkiocg_destroy,
+       .populate = blkiocg_populate,
+#ifdef CONFIG_BLK_CGROUP
+       /* note: blkio_subsys_id is otherwise defined in blk-cgroup.h */
+       .subsys_id = blkio_subsys_id,
+#endif
+       .use_id = 1,
+       .module = THIS_MODULE,
+};
+EXPORT_SYMBOL_GPL(blkio_subsys);
 
 struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup)
 {
        return container_of(cgroup_subsys_state(cgroup, blkio_subsys_id),
                            struct blkio_cgroup, css);
 }
+EXPORT_SYMBOL_GPL(cgroup_to_blkio_cgroup);
 
-void blkiocg_update_blkio_group_stats(struct blkio_group *blkg,
-                       unsigned long time, unsigned long sectors)
+/*
+ * Add to the appropriate stat variable depending on the request type.
+ * This should be called with the blkg->stats_lock held.
+ */
+void io_add_stat(uint64_t *stat, uint64_t add, unsigned int flags)
+{
+       if (flags & REQ_RW)
+               stat[IO_WRITE] += add;
+       else
+               stat[IO_READ] += add;
+       /*
+        * Everywhere in the block layer, an IO is treated as sync if it is a
+        * read or a SYNC write. We follow the same norm.
+        */
+       if (!(flags & REQ_RW) || flags & REQ_RW_SYNC)
+               stat[IO_SYNC] += add;
+       else
+               stat[IO_ASYNC] += add;
+}
+
+void blkiocg_update_timeslice_used(struct blkio_group *blkg, unsigned long time)
 {
-       blkg->time += time;
-       blkg->sectors += sectors;
+       unsigned long flags;
+
+       spin_lock_irqsave(&blkg->stats_lock, flags);
+       blkg->stats.time += time;
+       spin_unlock_irqrestore(&blkg->stats_lock, flags);
 }
+EXPORT_SYMBOL_GPL(blkiocg_update_timeslice_used);
+
+void blkiocg_update_request_dispatch_stats(struct blkio_group *blkg,
+                                               struct request *rq)
+{
+       struct blkio_group_stats *stats;
+       unsigned long flags;
+
+       spin_lock_irqsave(&blkg->stats_lock, flags);
+       stats = &blkg->stats;
+       stats->sectors += blk_rq_sectors(rq);
+       io_add_stat(stats->io_serviced, 1, rq->cmd_flags);
+       io_add_stat(stats->io_service_bytes, blk_rq_sectors(rq) << 9,
+                       rq->cmd_flags);
+       spin_unlock_irqrestore(&blkg->stats_lock, flags);
+}
+
+void blkiocg_update_request_completion_stats(struct blkio_group *blkg,
+                                               struct request *rq)
+{
+       struct blkio_group_stats *stats;
+       unsigned long flags;
+       unsigned long long now = sched_clock();
+
+       spin_lock_irqsave(&blkg->stats_lock, flags);
+       stats = &blkg->stats;
+       if (time_after64(now, rq->io_start_time_ns))
+               io_add_stat(stats->io_service_time, now - rq->io_start_time_ns,
+                               rq->cmd_flags);
+       if (time_after64(rq->io_start_time_ns, rq->start_time_ns))
+               io_add_stat(stats->io_wait_time,
+                               rq->io_start_time_ns - rq->start_time_ns,
+                               rq->cmd_flags);
+       spin_unlock_irqrestore(&blkg->stats_lock, flags);
+}
+EXPORT_SYMBOL_GPL(blkiocg_update_request_completion_stats);
 
 void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
                        struct blkio_group *blkg, void *key, dev_t dev)
@@ -48,6 +137,7 @@ void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
 #endif
        blkg->dev = dev;
 }
+EXPORT_SYMBOL_GPL(blkiocg_add_blkio_group);
 
 static void __blkiocg_del_blkio_group(struct blkio_group *blkg)
 {
@@ -82,6 +172,7 @@ out:
        rcu_read_unlock();
        return ret;
 }
+EXPORT_SYMBOL_GPL(blkiocg_del_blkio_group);
 
 /* called under rcu_read_lock(). */
 struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key)
@@ -98,6 +189,7 @@ struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key)
 
        return NULL;
 }
+EXPORT_SYMBOL_GPL(blkiocg_lookup_group);
 
 #define SHOW_FUNCTION(__VAR)                                           \
 static u64 blkiocg_##__VAR##_read(struct cgroup *cgroup,               \
@@ -116,22 +208,142 @@ static int
 blkiocg_weight_write(struct cgroup *cgroup, struct cftype *cftype, u64 val)
 {
        struct blkio_cgroup *blkcg;
+       struct blkio_group *blkg;
+       struct hlist_node *n;
+       struct blkio_policy_type *blkiop;
 
        if (val < BLKIO_WEIGHT_MIN || val > BLKIO_WEIGHT_MAX)
                return -EINVAL;
 
        blkcg = cgroup_to_blkio_cgroup(cgroup);
+       spin_lock(&blkio_list_lock);
+       spin_lock_irq(&blkcg->lock);
        blkcg->weight = (unsigned int)val;
+       hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) {
+               list_for_each_entry(blkiop, &blkio_list, list)
+                       blkiop->ops.blkio_update_group_weight_fn(blkg,
+                                       blkcg->weight);
+       }
+       spin_unlock_irq(&blkcg->lock);
+       spin_unlock(&blkio_list_lock);
+       return 0;
+}
+
+static int
+blkiocg_reset_write(struct cgroup *cgroup, struct cftype *cftype, u64 val)
+{
+       struct blkio_cgroup *blkcg;
+       struct blkio_group *blkg;
+       struct hlist_node *n;
+       struct blkio_group_stats *stats;
+
+       blkcg = cgroup_to_blkio_cgroup(cgroup);
+       spin_lock_irq(&blkcg->lock);
+       hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) {
+               spin_lock(&blkg->stats_lock);
+               stats = &blkg->stats;
+               memset(stats, 0, sizeof(struct blkio_group_stats));
+               spin_unlock(&blkg->stats_lock);
+       }
+       spin_unlock_irq(&blkcg->lock);
        return 0;
 }
 
-#define SHOW_FUNCTION_PER_GROUP(__VAR)                                 \
+void get_key_name(int type, char *disk_id, char *str, int chars_left)
+{
+       strlcpy(str, disk_id, chars_left);
+       chars_left -= strlen(str);
+       if (chars_left <= 0) {
+               printk(KERN_WARNING
+                       "Possibly incorrect cgroup stat display format");
+               return;
+       }
+       switch (type) {
+       case IO_READ:
+               strlcat(str, " Read", chars_left);
+               break;
+       case IO_WRITE:
+               strlcat(str, " Write", chars_left);
+               break;
+       case IO_SYNC:
+               strlcat(str, " Sync", chars_left);
+               break;
+       case IO_ASYNC:
+               strlcat(str, " Async", chars_left);
+               break;
+       case IO_TYPE_MAX:
+               strlcat(str, " Total", chars_left);
+               break;
+       default:
+               strlcat(str, " Invalid", chars_left);
+       }
+}
+
+typedef uint64_t (get_var) (struct blkio_group *, int);
+
+#define MAX_KEY_LEN 100
+uint64_t get_typed_stat(struct blkio_group *blkg, struct cgroup_map_cb *cb,
+               get_var *getvar, char *disk_id)
+{
+       uint64_t disk_total;
+       char key_str[MAX_KEY_LEN];
+       int type;
+
+       for (type = 0; type < IO_TYPE_MAX; type++) {
+               get_key_name(type, disk_id, key_str, MAX_KEY_LEN);
+               cb->fill(cb, key_str, getvar(blkg, type));
+       }
+       disk_total = getvar(blkg, IO_READ) + getvar(blkg, IO_WRITE);
+       get_key_name(IO_TYPE_MAX, disk_id, key_str, MAX_KEY_LEN);
+       cb->fill(cb, key_str, disk_total);
+       return disk_total;
+}
+
+uint64_t get_stat(struct blkio_group *blkg, struct cgroup_map_cb *cb,
+               get_var *getvar, char *disk_id)
+{
+       uint64_t var = getvar(blkg, 0);
+       cb->fill(cb, disk_id, var);
+       return var;
+}
+
+#define GET_STAT_INDEXED(__VAR)                                                \
+uint64_t get_##__VAR##_stat(struct blkio_group *blkg, int type)                \
+{                                                                      \
+       return blkg->stats.__VAR[type];                                 \
+}                                                                      \
+
+GET_STAT_INDEXED(io_service_bytes);
+GET_STAT_INDEXED(io_serviced);
+GET_STAT_INDEXED(io_service_time);
+GET_STAT_INDEXED(io_wait_time);
+#undef GET_STAT_INDEXED
+
+#define GET_STAT(__VAR, __CONV)                                                \
+uint64_t get_##__VAR##_stat(struct blkio_group *blkg, int dummy)       \
+{                                                                      \
+       uint64_t data = blkg->stats.__VAR;                              \
+       if (__CONV)                                                     \
+               data = (uint64_t)jiffies_to_msecs(data) * NSEC_PER_MSEC;\
+       return data;                                                    \
+}
+
+GET_STAT(time, 1);
+GET_STAT(sectors, 0);
+#ifdef CONFIG_DEBUG_BLK_CGROUP
+GET_STAT(dequeue, 0);
+#endif
+#undef GET_STAT
+
+#define SHOW_FUNCTION_PER_GROUP(__VAR, get_stats, getvar, show_total)  \
 static int blkiocg_##__VAR##_read(struct cgroup *cgroup,               \
-                       struct cftype *cftype, struct seq_file *m)      \
+               struct cftype *cftype, struct cgroup_map_cb *cb)        \
 {                                                                      \
        struct blkio_cgroup *blkcg;                                     \
        struct blkio_group *blkg;                                       \
        struct hlist_node *n;                                           \
+       uint64_t cgroup_total = 0;                                      \
+       char disk_id[10];                                               \
                                                                        \
        if (!cgroup_lock_live_group(cgroup))                            \
                return -ENODEV;                                         \
@@ -139,28 +351,42 @@ static int blkiocg_##__VAR##_read(struct cgroup *cgroup,          \
        blkcg = cgroup_to_blkio_cgroup(cgroup);                         \
        rcu_read_lock();                                                \
        hlist_for_each_entry_rcu(blkg, n, &blkcg->blkg_list, blkcg_node) {\
-               if (blkg->dev)                                          \
-                       seq_printf(m, "%u:%u %lu\n", MAJOR(blkg->dev),  \
-                                MINOR(blkg->dev), blkg->__VAR);        \
+               if (blkg->dev) {                                        \
+                       spin_lock_irq(&blkg->stats_lock);               \
+                       snprintf(disk_id, 10, "%u:%u", MAJOR(blkg->dev),\
+                                       MINOR(blkg->dev));              \
+                       cgroup_total += get_stats(blkg, cb, getvar,     \
+                                               disk_id);               \
+                       spin_unlock_irq(&blkg->stats_lock);             \
+               }                                                       \
        }                                                               \
+       if (show_total)                                                 \
+               cb->fill(cb, "Total", cgroup_total);                    \
        rcu_read_unlock();                                              \
        cgroup_unlock();                                                \
        return 0;                                                       \
 }
 
-SHOW_FUNCTION_PER_GROUP(time);
-SHOW_FUNCTION_PER_GROUP(sectors);
+SHOW_FUNCTION_PER_GROUP(time, get_stat, get_time_stat, 0);
+SHOW_FUNCTION_PER_GROUP(sectors, get_stat, get_sectors_stat, 0);
+SHOW_FUNCTION_PER_GROUP(io_service_bytes, get_typed_stat,
+                       get_io_service_bytes_stat, 1);
+SHOW_FUNCTION_PER_GROUP(io_serviced, get_typed_stat, get_io_serviced_stat, 1);
+SHOW_FUNCTION_PER_GROUP(io_service_time, get_typed_stat,
+                       get_io_service_time_stat, 1);
+SHOW_FUNCTION_PER_GROUP(io_wait_time, get_typed_stat, get_io_wait_time_stat, 1);
 #ifdef CONFIG_DEBUG_BLK_CGROUP
-SHOW_FUNCTION_PER_GROUP(dequeue);
+SHOW_FUNCTION_PER_GROUP(dequeue, get_stat, get_dequeue_stat, 0);
 #endif
 #undef SHOW_FUNCTION_PER_GROUP
 
 #ifdef CONFIG_DEBUG_BLK_CGROUP
-void blkiocg_update_blkio_group_dequeue_stats(struct blkio_group *blkg,
+void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
                        unsigned long dequeue)
 {
-       blkg->dequeue += dequeue;
+       blkg->stats.dequeue += dequeue;
 }
+EXPORT_SYMBOL_GPL(blkiocg_update_dequeue_stats);
 #endif
 
 struct cftype blkio_files[] = {
@@ -171,16 +397,38 @@ struct cftype blkio_files[] = {
        },
        {
                .name = "time",
-               .read_seq_string = blkiocg_time_read,
+               .read_map = blkiocg_time_read,
+               .write_u64 = blkiocg_reset_write,
        },
        {
                .name = "sectors",
-               .read_seq_string = blkiocg_sectors_read,
+               .read_map = blkiocg_sectors_read,
+               .write_u64 = blkiocg_reset_write,
+       },
+       {
+               .name = "io_service_bytes",
+               .read_map = blkiocg_io_service_bytes_read,
+               .write_u64 = blkiocg_reset_write,
+       },
+       {
+               .name = "io_serviced",
+               .read_map = blkiocg_io_serviced_read,
+               .write_u64 = blkiocg_reset_write,
+       },
+       {
+               .name = "io_service_time",
+               .read_map = blkiocg_io_service_time_read,
+               .write_u64 = blkiocg_reset_write,
+       },
+       {
+               .name = "io_wait_time",
+               .read_map = blkiocg_io_wait_time_read,
+               .write_u64 = blkiocg_reset_write,
        },
 #ifdef CONFIG_DEBUG_BLK_CGROUP
        {
                .name = "dequeue",
-               .read_seq_string = blkiocg_dequeue_read,
+               .read_map = blkiocg_dequeue_read,
        },
 #endif
 };
@@ -197,6 +445,7 @@ static void blkiocg_destroy(struct cgroup_subsys *subsys, struct cgroup *cgroup)
        unsigned long flags;
        struct blkio_group *blkg;
        void *key;
+       struct blkio_policy_type *blkiop;
 
        rcu_read_lock();
 remove_entry:
@@ -222,12 +471,16 @@ remove_entry:
         * we have more policies in place, we need some dynamic registration
         * of callback function.
         */
-       cfq_unlink_blkio_group(key, blkg);
+       spin_lock(&blkio_list_lock);
+       list_for_each_entry(blkiop, &blkio_list, list)
+               blkiop->ops.blkio_unlink_group_fn(key, blkg);
+       spin_unlock(&blkio_list_lock);
        goto remove_entry;
 done:
        free_css_id(&blkio_subsys, &blkcg->css);
        rcu_read_unlock();
-       kfree(blkcg);
+       if (blkcg != &blkio_root_cgroup)
+               kfree(blkcg);
 }
 
 static struct cgroup_subsys_state *
@@ -293,13 +546,32 @@ static void blkiocg_attach(struct cgroup_subsys *subsys, struct cgroup *cgroup,
        task_unlock(tsk);
 }
 
-struct cgroup_subsys blkio_subsys = {
-       .name = "blkio",
-       .create = blkiocg_create,
-       .can_attach = blkiocg_can_attach,
-       .attach = blkiocg_attach,
-       .destroy = blkiocg_destroy,
-       .populate = blkiocg_populate,
-       .subsys_id = blkio_subsys_id,
-       .use_id = 1,
-};
+void blkio_policy_register(struct blkio_policy_type *blkiop)
+{
+       spin_lock(&blkio_list_lock);
+       list_add_tail(&blkiop->list, &blkio_list);
+       spin_unlock(&blkio_list_lock);
+}
+EXPORT_SYMBOL_GPL(blkio_policy_register);
+
+void blkio_policy_unregister(struct blkio_policy_type *blkiop)
+{
+       spin_lock(&blkio_list_lock);
+       list_del_init(&blkiop->list);
+       spin_unlock(&blkio_list_lock);
+}
+EXPORT_SYMBOL_GPL(blkio_policy_unregister);
+
+static int __init init_cgroup_blkio(void)
+{
+       return cgroup_load_subsys(&blkio_subsys);
+}
+
+static void __exit exit_cgroup_blkio(void)
+{
+       cgroup_unload_subsys(&blkio_subsys);
+}
+
+module_init(init_cgroup_blkio);
+module_exit(exit_cgroup_blkio);
+MODULE_LICENSE("GPL");